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View Full Version : OBX goes frickin BOOM!!!!!!



turbovanmanČ
05-20-2006, 01:25 AM
Well, I guess if anyone can break one, its me. On my fourth run tonight at the street legals, just brake torquing it to do a burnout, aprox 15psi and it free revs, catches then a horrendous boom, followed by clicking. I shut it off and the starter goes your leaking tranny fluid bad. We push it off the track, a flat deck truck is there so we load it up, I jack up the van hoping an axle shaft let go. No such look, the aluminium diff case is cracked. $140 tow bill home, I guess no more drag racing for me. Sucks, I was just getting this thing dialed in. :banghead: :censored:

Whorse
05-20-2006, 01:35 AM
I have a picture of the crack if you want. Lemme know if you want me to upload it.

turbovanmanČ
05-20-2006, 01:40 AM
Here are some pics-

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics122.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics120.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics121.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics126.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics127.jpg

Whorse
05-20-2006, 01:44 AM
What did your Van weigh in at finally?

boost geek
05-20-2006, 01:56 AM
Sorry to hear that man, I can barely believe it! I was really looking forward to chasing your bumper. There's not a whole lot of options left now, without spending a pile of $$$$. Mission's spectator attendance at street legals will probably dwindle now...

turbovanmanČ
05-20-2006, 01:57 AM
What did your Van weigh in at finally?

3520 lbs with me in it, I weigh 190 lbs, 3 gallons of fuel and no rear seats.

jckrieger
05-20-2006, 02:16 AM
I'm curious to see what broke. Did you remember to torque those 8mm bolts on the housing? I'm willing to bet it's a spacer problem or a bolt problem.

turbovanmanČ
05-20-2006, 02:29 AM
I'm curious to see what broke. Did you remember to torque those 8mm bolts on the housing? I'm willing to bet it's a spacer problem or a bolt problem.


Yes I did.

Forgot to mention, I can spin the wheels now, there not locked together so its the diff, :censored:

jckrieger
05-20-2006, 02:34 AM
That sucks, you've gotta be running low on trans cases at this rate!

DodgeZ
05-20-2006, 02:37 AM
shat I am minutes away from installing my obx. pull the cover and lets see if it was the diff.

turbovanmanČ
05-20-2006, 02:37 AM
That sucks, you've gotta be running low on trans cases at this rate!


Actually, this is my first tranny case, I have 2 spare cases at work but no time. If I don't go away this weekend, I'll take it apart and see if I can get it welded back up in the van.

SpoolinGLH
05-20-2006, 02:50 AM
Damn, I am REAL curious to see what exactly went wrong. I thought it was practically impossible to break a obx or quaife. Leave it up to you simon :rolleyes:

Mike_Shepard
05-20-2006, 02:59 AM
jezus man that sux

WOP'R
05-20-2006, 04:19 AM
:faint: WOW

im sorry Simon,thats...thats freakn nuts!!:mad: :censored:

Rattlesnake
05-20-2006, 04:39 AM
Sorry Simon, But look at it like this: She is getting faster.:thumb:

show-off
05-20-2006, 07:04 AM
Sorry to hear that man. You have an automatic that you had to rig the OBX into right? Did you do any work to the diff?

Lets hope the manuals don't have that problem!!! We will find out if the OBX will handle big power this week...we the beast goes to Darlington.

GLHSKEN
05-20-2006, 07:51 AM
That's racing.. lots of pain ($$$ and time) for those gains. Sorry to hear it Simon!

uwilluz
05-20-2006, 08:58 AM
I thought it was practically impossible to break a obx or quaife. Leave it up to you simon :rolleyes:


I'm surprised Ken hasn't broken one by now.... or maybe he HAS??

LOL what was that motivational poster up a while ago? ANVIL: Yes, Ken Adler could break it! :p

mcsvt
05-20-2006, 09:23 AM
Sorry to hear that Simon :(

BadAssPerformance
05-20-2006, 09:35 AM
Wow, that sucks Simon... being a 5-speed guy I hope its not the diff itself.

Glad to hear it went faster tho! :thumb:

"Top Fuel" Bender
05-20-2006, 09:36 AM
I'm surprised Ken hasn't broken one by now.... or maybe he HAS??

LOL what was that motivational poster up a while ago? ANVIL: Yes, Ken Adler could break it! :p


Not BRO-KEN
You did see his broken trans case right?
I crack my auto too but not like Ken
He did it right

The S is Silent
05-20-2006, 10:32 AM
I also hope it isn't the OBX...I have on sitting in my a555 right now, and I'm stuck with it, good or bad.

boost geek
05-20-2006, 11:41 AM
I wonder if his ring gear bolts let loose, they had quite a bit of the head ground off...

jckrieger
05-20-2006, 12:37 PM
And bolts lose their strength when you heat them up (ie after grinding).

turbovanmanČ
05-20-2006, 02:13 PM
It has to be the diff, hence it freewheeled then went BOOM and I can now rotate the wheels one when is held, it will move both at first then you can spin just one if you spin it harder. Its done. :(

boost geek
05-20-2006, 03:03 PM
Could this be another case of ATF used in the place of gear oil? Do Torsen gears get proper lubrication with ATF? I know, your running an auto, you dont really have a choice. Are there many other auto OBX's out there?

turbovanmanČ
05-20-2006, 03:17 PM
Could this be another case of ATF used in the place of gear oil? Do Torsen gears get proper lubrication with ATF? I know, your running an auto, you dont really have a choice. Are there many other auto OBX's out there?

Carl aka DblTbl is using one in an auto. I also use synthetic lube. I could have got a bad one but I will see exactly what happened when I tear it down, sometime next week.

looneytuner
05-20-2006, 04:35 PM
You are such a hit at the track, you might just get some money from the track to keep the attendance up. ;)

Dave
05-20-2006, 08:07 PM
Damnit Simon. I thought you were done breakin' stuff!

Did the OBX's come with any kind of gaurantee? You had it for installed for less than a month.

Ergh, oh well, get a new one and try again.

BTW, get us some pics with the cover removed.

To everybody else, OhioRob is using a Quaiffe (similar posi) in his A420 automatic tranny. He's making around 550HP and hooks right up (1.6 60's). I don't think he's every had a problem.

GLHSKEN
05-20-2006, 08:17 PM
Not BRO-KEN
You did see his broken trans case right?
I crack my auto too but not like Ken
He did it right


Why thank you... Thank you very much!!! I make everyone else faster and break my own stuff.. Oh well.. Gives me time to play in the garage.

Subliminal
05-21-2006, 07:12 AM
Damn, Simon, that sucks to hear!

Time for a 555. Racing autos is for girls and children anyway. ;)

BadAssPerformance
05-21-2006, 08:30 AM
So with a 555, he can break axles and clutches like the rest of us 5-speed guys :thumb:

also, see previous BRO-KEN posts about breaking 5-speeds

tryingbe
05-21-2006, 12:19 PM
Time to upgrade.

Whorse
05-21-2006, 01:48 PM
Simon, you keep saying you've got a 568 lying around, and for the life of me I want you to change your mind to actually use it, or else give it to me in exchange for my rebuilt 413 so you can have a backup tranny if you want to race yours as is.

boost geek
05-21-2006, 02:52 PM
It doesn't matter what kinda tranny he is running, he will always have issues with the diff being such a heavy vehicle. His tranny seems to hold up fine.

Whorse
05-21-2006, 03:56 PM
I thought there were other problems before that I guess seemed to be fixed with more clutches, new TC, higher line pressure. People are running much more power in vehicles almost as heavy, so there has to be a logical solution out there.

Ground Rat
05-21-2006, 08:30 PM
Hmm, I guess I won't be going with an OBX in my mini then. :(

WVRampage
05-21-2006, 10:26 PM
Sorry to hear that Simon Id realy liek to see what went wrong in there.

turbovanmanČ
05-22-2006, 11:23 PM
I just got back from bike racing and next week is cancelled so I have alot more free time. I will take it apart and see what happened, maybe even tomorrow night????

Jason, I love my auto, I have all the little nagging issues fixed except a diff I guess. I have only broken one tranny and it was my fault for not tightening down the transfer gears properly. As Dick said, no matter what I install, I am going to break it by the looks of things. :(

Whorse
05-23-2006, 12:00 AM
Yes we all know you love your auto transmission, but I think if you want to keep it auto, you'll have to save and spend the money on something like a quaife.

DodgeZ
05-23-2006, 09:24 AM
I just got back from bike racing and next week is cancelled so I have alot more free time. I will take it apart and see what happened, maybe even tomorrow night????

Jason, I love my auto, I have all the little nagging issues fixed except a diff I guess. I have only broken one tranny and it was my fault for not tightening down the transfer gears properly. As Dick said, no matter what I install, I am going to break it by the looks of things. :(
The wait is killing us!

Clay
05-23-2006, 11:55 AM
yes! Killing!!!!!!

ludwig340
05-23-2006, 02:26 PM
I bet you couldn't break these brake pads!! ;) Heh. Just kidding dude, that's really weak...hopefully you'll find something stupid, get good and drunk, then come back to it later and get it back on the track!

I hadn't seen your more recent faster times - keep it up, man!

turbovanmanČ
05-23-2006, 02:31 PM
Keep waiting, muhahaahahaha! :evil:

BadAssPerformance
05-23-2006, 05:17 PM
Keep waiting, muhahaahahaha! :evil:

Get off your duff bro! ;)

Frank
05-23-2006, 08:36 PM
I lay a beer on it being the OBX-ATX spacer, or a fastner, that broke your tranny, not the OBX. If I am right, then I will finish my statement as to why.


Frank

turbovanmanČ
05-23-2006, 08:44 PM
I lay a beer on it being the OBX-ATX spacer, or a fastner, that broke your tranny, not the OBX. If I am right, then I will finish my statement as to why.


Frank

Then explain the fact I can turn the wheels opposite of each other, when one wheel is on the ground, I can turn the other one, and the fact I was loading it when it freewheeled for a few secs then caught and went boom? :(

The spacer letting go won't affect any of the 3 things I mentioned.

Frank
05-23-2006, 08:56 PM
I think the OBX is the last thing to go. Typically I would say the axle snapped inside the case. However since it makes a lot of noise, I bet you the ring gear came loose from the spacer, or those from the carrier, which will give you the same effect... typically.

BadAssPerformance
05-23-2006, 09:53 PM
By the way, Simon, did you open it up yet?

BadAssPerformance
05-23-2006, 09:53 PM
How about now? :D

Frank
05-23-2006, 09:54 PM
What about now?

BadAssPerformance
05-23-2006, 09:55 PM
Is it apart yet?

Turbo Joe
05-23-2006, 09:56 PM
simmon please let us know, i'm about to finish my tranny and before i put it in the car i want to know what happened..please...

MiniMopar
05-23-2006, 09:58 PM
Simon,

My OBX acts like an open diff too, now that it is broken in. They are not LSDs. They just bias the input torque. When free-wheeling, they have no torque to work with so they act like an open diff. Think about how they work...it's just a bunch of free-spinning gears.

As I mentioned in the other thread, when new, the gears bind up. It's probably due to the poor quality machining inside. I could torque the lug nuts just by having the other wheel on the ground when I first put it together. It acted really wierd for the first few miles, but now it is pretty much normal. I only notice the heavy steering when I get into it...but at that point its hard to tell the difference between the biasing and the torque-steer.

MiniMopar
05-23-2006, 10:02 PM
No pressure man...LOL.

Clay
05-23-2006, 10:14 PM
how about now??

jckrieger
05-23-2006, 10:22 PM
I'll paypal you $1 if you take it apart tomorrow. It'll even be one of those cool US dollars :)

Clay
05-23-2006, 10:43 PM
wow! thats like enough to buy an OBX in canada!!!!!

Whorse
05-23-2006, 10:44 PM
that's a whole 89 cents simon. That goes a long way to getting an SMP tranny!

turbovanmanČ
05-23-2006, 10:47 PM
I'll paypal you $1 if you take it apart tomorrow. It'll even be one of those cool US dollars :)


Your US money is worthless, its like 92 cents now, :lol:

And NO, its not apart yet. I think with enough donations, I could take it apart tonight, hehehhee! :evil: :eyebrows:




Simon,

My OBX acts like an open diff too, now that it is broken in. They are not LSDs. They just bias the input torque. When free-wheeling, they have no torque to work with so they act like an open diff. Think about how they work...it's just a bunch of free-spinning gears.
.


Russ, putting my slicks on, it still would lock the free wheel, I could tighten my lug nuts with one wheel on the ground. Also, I couldn't turn the wheels in the opposite direction either? weird.

Dave
05-23-2006, 10:59 PM
Simon, get in that damn garage, and you rip open that *** **** case, RIGHT NOW! Or I'm getting the belt. :mad:

Aries_Turbo
05-23-2006, 11:01 PM
even quaifes free wheel when a wheel is off the ground. I had one in my SHO and frank had/has one in a shadow. I even got stuck in a snowdrift once in the SHO cause I forgot that you had to apply the brakes to get the torque to shift from one side to the other cause its not a LSD. I bet you broke those bolts that you ground.

Sorry to hear about the bad news but it might not be a wash yet. :)

Brian

turbovanmanČ
05-23-2006, 11:02 PM
Simon, get in that damn garage, and you rip open that *** **** case, RIGHT NOW! Or I'm getting the belt. :mad:


Holy crap, patience my young lad, ;)

Whorse
05-23-2006, 11:05 PM
Are you there yet?

Turbo Joe
05-23-2006, 11:10 PM
how about now?????

Whorse
05-23-2006, 11:12 PM
What about now?

MiniMopar
05-23-2006, 11:25 PM
Russ, putting my slicks on, it still would lock the free wheel, I could tighten my lug nuts with one wheel on the ground. Also, I couldn't turn the wheels in the opposite direction either? weird.

Dude! It wasn't even broken-in yet! Hopefully it isn't just plain broken now...LOL.

turbovanmanČ
05-23-2006, 11:30 PM
Oh, it was broken in all right, :eyebrows:


Anyhow, NO, not NOW.

Whorse
05-23-2006, 11:34 PM
What about now?

BadAssPerformance
05-23-2006, 11:47 PM
Are you done yet?

turbovanmanČ
05-23-2006, 11:56 PM
Yep, its apart and NO ONE got it right. I had a small idea at the back of my mind but refused to believe it.

BadAssPerformance
05-23-2006, 11:57 PM
So what was it? pics?

BadAssPerformance
05-23-2006, 11:57 PM
Got pics yet?

BadAssPerformance
05-23-2006, 11:58 PM
How about now?

turbovanmanČ
05-23-2006, 11:58 PM
Maybe I'll let you guys hang, muhahaaha! :evil:

Whorse
05-24-2006, 12:02 AM
Didn't you leave enough people hanging on Friday?

Heh, sorry low blow, but all things said, once they got the track going after your little mess it rained. Quite a few unhappy campers.

turbovanmanČ
05-24-2006, 12:05 AM
Didn't you leave enough people hanging on Friday?

Heh, sorry low blow, but all things said, once they got the track going after your little mess it rained. Quite a few unhappy campers.

Too frickin bad, I am not the only one who has ever done that, I have lost numerous runs to crashes and broken parts by other cars. As the old saying goes, sh*t happens.


Anyhow, the teeth stripped off the output shaft gear to ring gear, :censored:


So now WTF do I do?

Whorse
05-24-2006, 12:20 AM
Yeah I know. Most of the guys who seem like they've been there many times didn't care and were supportive of you and your van, it was mostly the douchebags in mustangs and the imports complaining.

The way I see it, if you don't break anything while racing once in a while, you're either not trying hard enough, or you didn't build the car yourself.

turbovanmanČ
05-24-2006, 12:25 AM
Yeah I know. Most of the guys who seem like they've been there many times didn't care and were supportive of you and your van, it was mostly the douchebags in mustangs and the imports complaining.

The way I see it, if you don't break anything while racing once in a while, you're either not trying hard enough, or you didn't build the car yourself.

Thats funny, last Friday-before last Friday, lol, 2 Mustangs let go and we were delayed for 45 mins.

jckrieger
05-24-2006, 12:36 AM
Too frickin bad, I am not the only one who has ever done that, I have lost numerous runs to crashes and broken parts by other cars. As the old saying goes, sh*t happens.


Anyhow, the teeth stripped off the output shaft gear to ring gear, :censored:


So now WTF do I do?

You need to get one of dem solid pinions and try it again! There might also be another final drive ratio that would be a little stronger. It's like RWD apps, the higher numerically the ratio, the weaker the gearset.

Whorse
05-24-2006, 12:39 AM
You should in a way be proud. I'm almost in awe after witnessing one of the first people to break an OBX. I had it on video, but no sound sadly. Too bad eh.

jckrieger
05-24-2006, 12:42 AM
It wasn't the OBX that broke, right? It was the final drive ring and pinion!

turbovanmanČ
05-24-2006, 01:29 AM
You need to get one of dem solid pinions and try it again! There might also be another final drive ratio that would be a little stronger. It's like RWD apps, the higher numerically the ratio, the weaker the gearset.


I have one but I doubt it will help. What difference would a solid one make?

Anyhow, pics 'cause people are bugging me.


http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics132.jpg


http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics135.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics136.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics137.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Broken%20trans%20and%20OBX%20LSD%20pics/Canoncamerapics141.jpg

TurboJerry
05-24-2006, 01:59 AM
The 2.85:1 is the strongest. 21 pinion teeth, and 60 ring gear teeth. I know the 3.05 will go 8.30's and faster.(20 and 61) The hole has nothing to do with it. I've seen the pinion crack to the inside of the hole though. The gears are 59 to 60 rockwell.(hardness) Maybe this is just a fluke? They may have been hardened to the point of being brittle from the factory........ I'd use a solid 1 just to play it safe.

Frank
05-24-2006, 08:13 AM
I would really love to see pictures up close pictures in natural light of the teeth that broke off the ring and pinion to see what types of breaks they are.....


Frank

MiniMopar
05-24-2006, 08:58 AM
Is the spacer made of steel? I'm wondering if case flex or something else moving caused poor tooth engagement? That's the theory behind the chrome-moly plate on the A525/520/555 anyway, not that one of those would help here. Do you suppose that grinding on the trans case is leading to strength problems?

Folks have been putting crazy torque through these things for a long time now. You don't see this kind of failure very often on an A413.

As far as being right...we were right that it wasn't the diff. ;)

Even so, I'd take it apart to make sure there are no gear teeth inside.

MiniMopar
05-24-2006, 09:03 AM
Actually, I suppose it's possible that the OBX did go and then locked-up, which then killed the output shaft gear.

Clay
05-24-2006, 09:04 AM
SO, is the OBX still good with all the crap that was running through the trans?

Frank
05-24-2006, 09:06 AM
Is the spacer made of steel? I'm wondering if case flex or something else moving caused poor tooth engagement? That's the theory behind the chrome-moly plate on the A525/520/555 anyway, not that one of those would help here. Do you suppose that grinding on the trans case is leading to strength problems.

Folks have been putting crazy torque through these things for a long time now. You don't see this kind of failure very often on an A413.

As far as being right...we were right that it wasn't the diff. ;)

Exactly.... my unfinished statement has to do with the spacer and how it is constructed. I have serious concern over it. My original plan with Cliff was to build a set of these using aluminum and a single set of extended fasteners which just clap the spacer. We felt aluminum is fine since the load is shared between the spacer and the fasteners provided you build the spacer with proper tolerances and such. The spacer that Simon has a set of fasteners which clamp the ring gear to the spacer and then a set which clamp the spacer to the carrier. It is also made out of aluminum. Not only is the meat between the fasteners reduced, but it is making the spacer completely load bearing. BAD IDEA and I will continue to say that even if it isnt what causes Simon's damage.

From the looks of Simon's damage, aka, the cracking of the case, something pushed the ring gear away from the pinion. So that means either something large was caught between the ring gear and pinion, or their was torsional flexing of the ring gear with respect to the carrier since the cracking occured along the bearing centerline.


Frank

Frank
05-24-2006, 09:09 AM
Actually, I suppose it's possible that the OBX did go and then locked-up, which then killed the output shaft gear.


I dont see how that is different then a brake stand since he was barely moving. If he was moving at a good clip, then I could see it causing something, but I would suspect the insides of the OBX to rip apart first before causing output shaft gear... (what I tend to call pinion gear, which maynot be right.)

DodgeZ
05-24-2006, 09:22 AM
Actually, I suppose it's possible that the OBX did go and then locked-up, which then killed the output shaft gear.


Wouldn't just acted like a welded up diff?

DodgeZ
05-24-2006, 09:24 AM
From the looks of Simon's damage, aka, the cracking of the case, something pushed the ring gear away from the pinion. So that means either something large was caught between the ring gear and pinion, or their was torsional flexing of the ring gear with respect to the carrier since the cracking occured along the bearing centerline.


Frank


If one of the teeth busted off couldn't it have got caught in the next pair of teeth? causing it to tear up more and push the diff away?

MiniMopar
05-24-2006, 10:28 AM
Wouldn't just acted like a welded up diff?

Yeah, it would. It's was just a thought. For instance if the splines stripped, and diff would start to free wheel, then if the bits got jammed in the element gears, it would suddenly lock up.

I was just trying to make Simon feel better, since he seems bummed that the OBX isn't obviously destroyed.

MiniMopar
05-24-2006, 10:30 AM
Exactly.... my unfinished statement has to do with the spacer and how it is constructed. I have serious concern over it. My original plan with Cliff was to build a set of these using aluminum and a single set of extended fasteners which just clap the spacer. We felt aluminum is fine since the load is shared between the spacer and the fasteners provided you build the spacer with proper tolerances and such. The spacer that Simon has a set of fasteners which clamp the ring gear to the spacer and then a set which clamp the spacer to the carrier. It is also made out of aluminum. Not only is the meat between the fasteners reduced, but it is making the spacer completely load bearing. BAD IDEA and I will continue to say that even if it isnt what causes Simon's damage.

OK, I didn't realize how the spacer worked. I assumed that it was just clamped between the gear and the carrier using a long set of bolts. It seems like the method used here would work OK if the spacer was made out of some strong steel.

Frank
05-24-2006, 10:35 AM
Yeah, it would. It's was just a thought. For instance if the splines stripped, and diff would start to free wheel, then if the bits got jammed in the element gears, it would suddenly lock up.

I was just trying to make Simon feel better, since he seems bummed that the OBX isn't obviously destroyed.


And this is why I want to see an up close and personal picture of the teeth to see the type of fractures. Kind of hard to explain, but I feel that the fractures will be versley different if something got wedged (a tooth broke off), the ring gear started to free wheel and recatch (like if the OBX flexed), or different markes if they broke under stress (what Simon seems to think, except it doesnt explain the MASSIVE crack of the case).


Frank

Frank
05-24-2006, 10:36 AM
OK, I didn't realize how the spacer worked. I assumed that it was just clamped between the gear and the carrier using a long set of bolts. It seems like the method used here would work OK if the spacer was made out of some strong steel.

Exactly how Cliff Ramsdell and myself felt about it.


Frank

looneytuner
05-24-2006, 10:56 AM
The spacer is Steel with a double set of bolts. Bolts are one set stock and one set cap head 12.9. It's possible the case had fractures from previous dif grenades. Stock dif grenade, AB grenade. The ring gear did not look great in pics of the obx install. I seem to remember wondering about some marks on it. It's possible the case broke and the gears climbed over each other, then destructed.

altered7151
05-24-2006, 11:17 AM
I have to agree with Frank on this one. There is alot more shear stress on the bolts the way they are set up now. Actually I take that back, same shear stress regardless of design, but the way they are set up now there is alot less bolt there to deal with it. Is it possible that there was enough torsional stress on the ring gear to twist it on the spacer and misalign it with the pinion? I think maybe the broken teeth were a result of the problem not a cause. Maybe the gears misaligned from the torsional twist to the point it started eating up the gears, which would explain the freewheeling, then a broken off tooth got wedged inbetween the two and pushed the pinion away from the ring gear hard enough to crack the case.

MiniMopar
05-24-2006, 12:11 PM
I suppose some answers may come by observing the torque required to remove the bolts from the spacer. If they stretched at all, they should come out with less torque (though any locktite may skew such results).

Looking back at what Simon said initially, chances are good that the case cracked during the horrendous boom at the end. The question to me is: did the teeth strip off before, during, or after it started freewheeling.

jckrieger
05-24-2006, 12:19 PM
I think it's time to build a trans that hasn't had debris through it and try it again!

If somebody has a LOT of time on their hands, it'd be cool to see a Pro-E model and a rough stress analysis on this spacer design. I'd do it, but it'll be about 8 months before I have the abilities.

turbovanmanČ
05-24-2006, 12:20 PM
Well guys, all good theories, :thumb:

I would say the grinding of the case didn't cause any of this as that part is at the back and far away from the crack.

I would agree jammed teeth caused the cracked case due to the teeth jamming and the force had to go somewhere, IE the cracked case, and the diff cover is bent out at the bottom from more teeth being pushed where they shouldn't.

Spacer bolts-the one's I ground look perfect, no signs of movement etc and there no signs of the spacer moving around.

I was either the mesh is off due to the spacer being used which doesn't really make sense as they were perfectly inline AND its in the same relative position. I would venture to say that the previous diff explosion and resulting caranage weakened the gear. There were no marks I could see on the ring gear and driven gear after my first grenade, just casting marks. When I get it apart, I will examine it more closely.

One other thing is maybe we need to tighten up the bearing preload? due to the extra mass of the OBX, it could be flexing away from the driven gear hence the teeth getting sheared off?????????

MiniMopar
05-24-2006, 12:28 PM
I haven't been paying attention prior to your OBX installation. I didn't realize that this tranny had a prior incident. I would say that it should be safe to put together a clean tranny with known good parts without any major changes. I would definitely take the OBX apart though.


One other thing is maybe we need to tighten up the bearing preload? due to the extra mass of the OBX, it could be flexing away from the driven gear hence the teeth getting sheared off?????????

Good idea, especially on a race car that doesn't see many street miles. What side of the spec'd range were you on when you set it up? For instance, I always go with zero play with a slight drag on the input shaft for manual trannies, even though the FSM specs some play even on new bearings. Once the bearings have a few thousand on them, they end up with the correct amount of play (tight end of the band). I've found that this improves the longevity of the input shaft seal.

Adding a few more inch pounds to the diff preload probably won't hurt anything, especially when you consider the kinds of loads they see under stress. In fact, the case probably flexes so much that any preload is moot anyway.

turbovanmanČ
05-24-2006, 01:06 PM
I put it on the tight side, they call for no play and a 5-10 inch lb turning torque. I was around 10.

The more I think about what happened, the more I believe its one of 2 things, trans case cracked causing the teeth to lose mesh while loading it up OR the output teeth just got fatiqued with age.

I am going to build a thick alumnium diff cover to help keep the case from distorting. 1/4 inch or 1/2??????

MiniMopar
05-24-2006, 01:08 PM
Well, the thicker the better, I guess. 1/4" seems like plenty, though.

inmyshadow
05-24-2006, 01:20 PM
My Quaife doesn't free wheel. I put the car in the air, spin one tire. The other tire turns the same direction.


even quaifes free wheel when a wheel is off the ground. I had one in my SHO and frank had/has one in a shadow. I even got stuck in a snowdrift once in the SHO cause I forgot that you had to apply the brakes to get the torque to shift from one side to the other cause its not a LSD. I bet you broke those bolts that you ground.

Sorry to hear about the bad news but it might not be a wash yet. :)

Brian

MiniMopar
05-24-2006, 01:36 PM
In Park (auto) or in a gear (manual)?

Frank
05-24-2006, 01:59 PM
We didnt say free wheel, put one wheel on the ground... the one in the air will free wheel. (or at least that is what I was talking about).


Anyway, trans-diff cover would probably be better if you where to use a piece of aluminum and machine it into shape to mate up, and then machine the inside to clear the diff. Honestly though, I dont think it will help much. Just get a new case that has no known failures and roll with it.


Frank

ludwig340
05-24-2006, 03:25 PM
What you all failed to notice was the foam tile flaking off of the case and lodging into the mechanism causing the catastrophic failure...we've been using this foam successfully for years without such a failure...

It's sad that Van Hellen has to suffer for our miscalculations...:(



(Sorry, it just sounded like NASA in here for a minute...heh...)

MiniMopar
05-24-2006, 04:11 PM
Heh...it took me a while but I get it now. :p

turbovanmanČ
05-24-2006, 04:25 PM
The 2.85:1 is the strongest. 21 pinion teeth, and 60 ring gear teeth. I know the 3.05 will go 8.30's and faster.(20 and 61) The hole has nothing to do with it. I've seen the pinion crack to the inside of the hole though. The gears are 59 to 60 rockwell.(hardness) Maybe this is just a fluke? They may have been hardened to the point of being brittle from the factory........ I'd use a solid 1 just to play it safe.

Thanks, excellent info. :thumb:

ludwig340
05-24-2006, 04:33 PM
Heh...it took me a while but I get it now. :p

:D

It's okay...my jokes sometimes transcend whole serious/humorous paradigm (read: only funny to me) ;)...

BadAssPerformance
05-24-2006, 08:32 PM
Holy thread proliferation batman! one day ou tof town and this thread goes nuts!

Glad to hear it's not the OBX... :thumb:

boost geek
05-24-2006, 09:18 PM
I've never seen inside one of these automatic trannys, but when the 5 speed pinion side bearing goes, the main shaft will wobble quite a lot, mine had over 1/4 inch of movement when I took it apart (A525), up, down, and sideways. The teeth would then be too far away from the ring gear.

TurboJerry
05-25-2006, 04:32 AM
I don't use the inch lbs method of preload. I do it like the old RWD diffs. I put 0.008" to 0.010" preload on the diff bearings. I put about 0.001" to 0.002" on the pinion bearings. The pinion will not freewheel easily with slight preload when installed all by it's lonesome, but it keeps the pinion from being too loose. (I have a problem with tapered bearings having play like the factory says) Also any wheel hop or tire shake will kill the toughest parts. There's nothing that can be done except to cure the tire shake. Sorry to be blunt, but a "girdle" will not help. The forces of steel gear teeth getting caught between gears will blow anything apart.

turbovanmanČ
05-25-2006, 12:59 PM
I don't use the inch lbs method of preload. I do it like the old RWD diffs. I put 0.008" to 0.010" preload on the diff bearings. I put about 0.001" to 0.002" on the pinion bearings. The pinion will not freewheel easily with slight preload when installed all by it's lonesome, but it keeps the pinion from being too loose. (I have a problem with tapered bearings having play like the factory says) Also any wheel hop or tire shake will kill the toughest parts. There's nothing that can be done except to cure the tire shake. Sorry to be blunt, but a "girdle" will not help. The forces of steel gear teeth getting caught between gears will blow anything apart.

Thanks. I also don't believe in free play. I will maybe tighten it up a bit, it had some resistance to turn but maybe I'll make it a bit tighter.

Looking at the broken teeth, I notice that the first 1/16. lengthwise, is a nice clean break, then the rest is all rough? is that fatique?

Clay
05-25-2006, 02:00 PM
Thanks. I also don't believe in free play. I will maybe tighten it up a bit, it had some resistance to turn but maybe I'll make it a bit tighter.

Looking at the broken teeth, I notice that the first 1/16. lengthwise, is a nice clean break, then the rest is all rough? is that fatique?

typically the 'nice clean break' is catastrophic, ie all at once. The rough area is typically from a fracture that has started at one edge, and worked its way in, slowly (ie fatigue-ish). Once the fracture gets so far across the surface, the rest will just break off, which is why you have the area with a nice clean break.

clay

turbovanmanČ
05-25-2006, 02:06 PM
typically the 'nice clean break' is catastrophic, ie all at once. The rough area is typically from a fracture that has started at one edge, and worked its way in, slowly (ie fatigue-ish). Once the fracture gets so far across the surface, the rest will just break off, which is why you have the area with a nice clean break.

clay

So that would imply what?

Clay
05-25-2006, 02:24 PM
Im going to speculate some kind of repeated impact loading caused the initial fracture, then one last impact finished the job.

Now, why that is could be any number of reasons (teeth depth off, to much lash, inclusion in metal, metal fatigue, pouricty in metal, bad spot in surface hardening, etc) Plus, it could have only been one or two bad teeth, but once that gear mesh gets out of wack, WATCH OUT!

r00tcause
05-25-2006, 04:11 PM
So with a 555, he can break axles and clutches like the rest of us 5-speed guys :thumb:

also, see previous BRO-KEN posts about breaking 5-speeds

If you want to avoid the "ken special" don't use an intermediate shaft.

DodgeZ
05-25-2006, 04:37 PM
So that would imply what?
http://www.joink.com/homes/users/cooke/ohhschnap.gif

Whorse
05-25-2006, 08:10 PM
Hahahahahaha

Aries_Turbo
05-27-2006, 01:11 AM
one question... did you check the whole diff/ring gear /spacer assembly for runout once installed in the case? just checking. if there was any runout the gears might not have meshed completely on the one side as it rotated. just a thought and something to double check for the future.

Brian

turbovanmanČ
05-27-2006, 01:18 AM
one question... did you check the whole diff/ring gear /spacer assembly for runout once installed in the case? just checking. if there was any runout the gears might not have meshed completely on the one side as it rotated. just a thought and something to double check for the future.

Brian


No I didn't but great minds think alike, I was going to do that when I swapped the cases. :thumb:

TurboJerry
05-27-2006, 03:55 AM
Once a crack starts, It runs away. (just like glass)The cracks were very small for a while, but then snapped all the way through very quickly. High rockwell numbers means brittle, then years of use / abuse means problems eventually. I would suggest having the next gears maged........

turbovanmanČ
05-27-2006, 12:35 PM
Once a crack starts, It runs away. (just like glass)The cracks were very small for a while, but then snapped all the way through very quickly. High rockwell numbers means brittle, then years of use / abuse means problems eventually. I would suggest having the next gears maged........


Good idea, although time is not on my side, I need my van back and running. The set I have now look good, solid pinion and no noticeable wear on the teeth. If I can find someone to do it on Monday, I'll get it done.

boost geek
05-27-2006, 10:30 PM
I have a feeling that brown van is going to be at Mission again on friday:eyebrows:

turbovanmanČ
05-27-2006, 10:32 PM
Well I got the tranny out today, took me all of 45mins and that was with plugging a tire for Shaun. Its cracked on top too, doh!

Next Legals are June 9th and I will be in Seattle bike racing so it will have to be July, thats the next one. :(

Frank
05-28-2006, 07:45 AM
More pictures!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

turbovanmanČ
05-28-2006, 03:58 PM
More pictures!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Your such a picture ho! :p

TurboJerry
05-29-2006, 02:13 AM
Look at the teeth *very* carefully if you don't mag them....... Cracks start *very* small.

turbovanmanČ
05-29-2006, 02:14 AM
Look at the teeth *very* carefully if you don't mag them....... Cracks start *very* small.

I realized I have alot more time so I will be getting the new/used output shaft magnafluxed. Should I have anything done to it?

TurboJerry
06-01-2006, 04:11 AM
There's not much else to be done. Cyro treating may help, but it's still a pot luck. I actually wanted to put the man trans gear tooth profile on new ring / pinion gears, because it seems no one has broken the man trans ring / pinion gears that I know of.......... I mentioned getting a TBI "set" elsewhere because the fire breathing HP of the TBI's usually won't be as bad as its turbo brethren.

turbovanmanČ
06-01-2006, 12:32 PM
Well, as far as I know and what people have said, I am the only one to do this. I have heard of breaking off the hollow gear?

TurboJerry
06-02-2006, 01:24 PM
Without analyzing the broken gears for material integrity, there is no way to really know what happened...... But I still think it was a fluke and shoulden't happen again with the right precautions taken. I don't think it's worth it to have them analyzed, since the QC is usually ok. But if you *really* want to know........

turbovanmanČ
06-02-2006, 02:19 PM
Without analyzing the broken gears for material integrity, there is no way to really know what happened...... But I still think it was a fluke and shoulden't happen again with the right precautions taken. I don't think it's worth it to have them analyzed, since the QC is usually ok. But if you *really* want to know........

I will see if I can pull a favour and see if I can get it analyzed.

DBB mini
06-06-2006, 11:25 PM
Sorry I've been out of the ring for a while. Simon sorry to hear about your carnage, but I'm relieved to see the spacer possibly withstood? The TIR (Runout) on all the spacers were held to within .001. Let me know if you need machine shop assistance on anything & good luck.

turbovanmanČ
06-06-2006, 11:31 PM
Thanks.

BTW, I haven't done a thing to it, been so busy at work, and bike racing season has begun so it could be another 2-4 weeks before I do it.

Also, Dodge F*cked up, they priced and sent me the wrong shaft, the proper one is $220 so I just got a good, low mileage used set from my tranny parts supplier, $75. It looks brand new, :thumb:

Turbo Joe
06-06-2006, 11:40 PM
I'm really glad it wasn't the obx unit. glad to hear that the mini is slowly but surely coming back along. take care!!

2.216VTurbo
06-07-2006, 10:07 AM
I'm really glad it wasn't the obx unit. glad to hear that the mini is slowly but surely coming back along. take care!!


I think there are a whole bunch of glad to hear the OBX is getting a clean bill of health on this one;)

looneytuner
06-07-2006, 02:15 PM
I'm really glad it wasn't the obx unit. glad to hear that the mini is slowly but surely coming back along. take care!
I think there are a whole bunch of glad to hear the OBX is getting a clean bill of health on this one
I would guess tbvnmn has mixed reactions.

turbovanmanČ
02-07-2011, 10:43 PM
Ha, old thread but figure its had 4.5 years of beating and so far, so good, :partywoot:

I have the pinion shaft for show and tell in my work office, lol.

black86glhs
02-07-2011, 11:07 PM
One of the first things you fixed that didn't break again soon after!!!! Awesome!!!:thumb::thumb:

Ondonti
02-08-2011, 12:38 AM
I am surprised the splines don't tear out with all the axles I have killed. The metal on the axles LOOKS better then the metal in the obx, a lot better. Recast Dutch oven leftover metal is holding up somehow.

Dave
02-08-2011, 09:37 AM
lol I just re-read the whole thread. Good to hear Simon. :thumb: