AWD pictures, video, weight, measurement

[Ondonti]

Here is what I did tonight. I lost my measuring tape so i need to buy one. I will take apart the rear end and weigh the pieces separately after weighing them together if possible.
Consider this a work in progress. I am out for good pictures and helpful info, not lots of posts in this thread. The AWD omni thread can be about that.

Measurements
63" wide at the rear end from the mating surface of each axle.
119" long from PTU shaft to center of rear end.

Weights:

PTU - 35 lb
driveshaft - 20 lb
Axle - 15 lb x2
Rear End - 57 lb
Coupler - 60 pounds
misc parts and bolts - 6 pounds

148 pounds minus coupler (probably 10 more pounds for lengthened driveshaft).

208 pounds with coupler.

Then add the weight of rear disc brake setup attacked to rear axle, or using your own axle. (not using crappy huge 8" wide minivan drums).



http://www.youtube.com/watch?v=Lv9RuNQVCdE



http://img300.imageshack.us/img300/3119/img3775xh3.jpg
http://img401.imageshack.us/img401/662/img3776jy5.jpg
http://img401.imageshack.us/img401/9228/img3777yf2.jpg
http://img186.imageshack.us/img186/7388/img3778wj4.jpg
http://img186.imageshack.us/img186/7008/img3779as0.jpg
http://img186.imageshack.us/img186/889/img3780gh4.jpg
http://img186.imageshack.us/img186/995/img3781ov9.jpg
http://img186.imageshack.us/img186/995/img3781ov9.jpg

[bradp]

Very cool, can't wait to see it finished

[Speedeuphoria]

So is that the diff from the donor? is it the same as a normal diff? or does it have extra splines like people have said?

[black86glhs]

Looks like a handful to drive. Otherwise, should make it real easy to put in something.

[CSXRT4]

does the driveshaft have any in-and-out moveability at the PTU end? Im thinking about attempting this AWD stuff too, id rather do a solid axle in the rear but that would require some in and out play for the driveshaft to accommodate for the up and down travel of the axle

[Ondonti]

Driveshaft cant move end to end.
Video states that the AWD Diff is being used.

If someone can get stock Diff's machined for AWD use, then maybe we can machine LSD's for the front.

[Speedeuphoria]

I just wanted to confirm that the diff was specific. The 3spd diff and the 4spd diff are not the same so people thinking this will swap into a 3spd auto need to know this.

Would help if you could post some pics of the diff so we can see if it what needs to be done to a stocker or if its possible.

[turbovanman²]

Interesting. I must resist the temptation to make mine AWD, lol.

[Ondonti]

you would have the easiest swap of all of us!
If we can make the rear ends easier, then its like nothing to go awd!

[turbovanman²]

you would have the easiest swap of all of us!
If we can make the rear ends easier, then its like nothing to go awd!

True but time and money on short order. It would be fun though, :nod:

[CSXRT4]

How much did that stuff cost you? I found a 92 AWD van and they want $350 for the PTU, pass. axle, and differential.

[BadAssPerformance]

Good tech! So whats it going in? :eyebrows:

[j4278h]

How much did that stuff cost you? I found a 92 AWD van and they want $350 for the PTU, pass. axle, and differential.


there are 2 97-99 awd vans local that you can get that stuff from.

if your interested pm me.

[Ondonti]

Weights. I have pictures but I dont know when I will feel like posting them all.

PTU - 35 lb
driveshaft - 20 lb
Axle - 15 lb x2
Rear End - 57 lb
Coupler - 60 pounds
misc parts and bolts - 6 pounds

148 pounds minus coupler (probably 10 more pounds for lengthened driveshaft).

208 pounds with coupler.

Then add the weight of rear disc brake setup attacked to rear axle, or using your own axle. (not using crappy huge 8" wide minivan drums).

If a Mod could add this to the first post, that would be nice.

[Clay]

Done.

[CSXRT4]

I grabbed this out of a '92 today, still no speedo cable :(

snapped a couple pics of interest, they gave me the torched off axle so this is what it looks like with the axle in

http://img221.imageshack.us/img221/8124/59513451um9.jpg
http://img221.imageshack.us/img221/5576/65554306uv2.jpg
http://img119.imageshack.us/img119/4913/98018260ab1.jpg
http://img261.imageshack.us/img261/2492/36101194gi9.jpg

[zin]

does the driveshaft have any in-and-out moveability at the PTU end?

The driveshaft has a spring-loaded slip joint allowing for the rocking of the engine.

Mike

[Aries_Turbo]

take the speed sensor out and pop in the earlier one with the speedo cable.

Brian

[135sohc]

what do those tanks on the rear end do ? looks like something with brake proportioning ? or is related to the power transfer

[CSXRT4]

take the speed sensor out and pop in the earlier one with the speedo cable.

Brian

I just noticed that was possible at work today lol. Do the later PTUs even have a speed sensor there at all?

[j4278h]

I just noticed that was possible at work today lol. Do the later PTUs even have a speed sensor there at all?



nope thats why the desire for the older one.

[CSXRT4]

nope thats why the desire for the older one.

that stinks that the later ones dont have it. Id like to have a couple extras and finding early AWD vans is going to be a lot harder :(

[CSXRT4]

Im trying to figure out the shear strength of the hollow shaft. I did some calcs based on this site http://physics.uwstout.edu/StatStr/Statics/Torsion/torse51a.htm


In a FWD system the driver axle gets half the load and the passenger axle gets half the load. In this AWD system the driver axle gets a quarter of the load, the passenger axle gets a quarter of the load, and the PTU input shaft gets half the load. This of course based on a perfect world, but likely the PTU input shaft would receive a little bit more load at a launch because the back tires will probably grip more than the front. But in a perfect world the input shaft of the PTU will see about the same torsional loads as the driver or passenger axle would normally see in a FWD system. After some rough calculations with rough measurements of the stock axle diameter and PTU input shaft diameter(internal and external) I came to the conclusion that the shear loads in the PTU input shaft are about 40% less than those on either drive axle in a FWD layout. Or I guess you could say the shear strength of the PTU shaft is about 40% greater than either drive axle in the FWD layout while also carrying the same torsional load. So it really should be able to hold a good amount of power.


Keep in mind I am not a physics pro, so if anybody could double check me that would be cool. Ill see if I can get some exact measurements of the PTU shaft and axle tomorrow

[CSXRT4]

Ok I did some measurements with a dial caliper and came up with this

PTU Input Shaft
Shaft Dia. = 1.355" but necks up to 1.495"
Inner Dia. = 1.115"
Wall Thickness = .12" (1/8th inch)
Dia. at Teeth = 1.455"

Stock Axle
Shaft Dia. = 1.045"
Dia. at Teeth = 1.075"


I re-did my shear calculations, I dunno if I did something wrong last time or maybe this time? But I came up with the PTU input shaft being 15% stronger in torsion at the shaft directly after the teeth, and 51% stronger in torsion when it necks up in diameter. Im guessing this is the weakest link in the PTU, but it should still be able to hold some good power. When people usually break an axle isn't it at the CV joint and not actually a shearing of the shaft?

I think when I put this in my car im going to throw in a spare PTU and beat the heck out of it with the front axles out so that all the power goes to the rear. I think this would be a good way to test the torque capacity of the PTU. If we have any problems with the PTU input shaft there is also the possibility of having a custom one made, the wall thickness could be increased on the inside a bit and it could be made out of a stronger material and from a stronger process.

[Ondonti]

I dont know how much room there is to go smaller inner diameter. The axle has to fit through. Maybe just the Steve locket heat treat....

Any ideas on sealing off the holes for the axle when you remove the front axles?

[Ondonti]

that stinks that the later ones dont have it. Id like to have a couple extras and finding early AWD vans is going to be a lot harder :( I am betting you can drill out the spot where it belongs and there will be something inside...i hope lol.


I have a bunch more pictures but I have not posted them yet. I took apart the rear coupler. The old style will NEVER break lol.

[Reaper1]

The REAL question about the strength of the PTU hollow shaft is what material is it made of and what kind of strengthening technique did they use on it? You REALLY need to know that stuff, then look at MIL Hndbk 5 to see how the shear stress you calculated compares to the yeild strength of the material.

Also, remember that the torque from the engine is multiplied by the gears of the transmission, so you have to take that in to account as well. Our axles see a LOT of stress when we lauch. IIRC the solid front axles can deflect up to 3* elastically during launch and the good hollow ones can see up to 7*!! That's a LOT of force!!!!

[Aries_Turbo]

the rear isnt going to see the total brunt of the attack because of the viscous coupling back there. now if you are contemplating RWD only like CSXRT4/Brent is talking above and using another axle, yeah then its gonna get the full force and the shock of the launch.

brent, just use those rubber plugs with the bolt/wingnut and crank them in there with the seal still in, that way it isnt permanent.

you could also have a metal piece machined with the diameter of the axle where it meets the seal with a lip on the inside and a threaded hole in the center that you could bolt a plate over the outside that is bigger than the seal inner diameter. bolt that over the seal and tap the seal back in.

Brian

[Ondonti]

The old school coupler is not viscous, its mechanical. If its on, its 100%.
It looks like a dog tooth engagement on a dog box.
I just wont get around to posting them till december, sorry. They are good pics.

All that vacuum stuff just ends up messing with an Actuator that moves a fork that brings the driveshaft coupler together to give RWD action.

If you want to break stuff, set up RWD only, slicks, put it in gear with the coupler released, rev limiter, actuate coupler. I sorta doubt it would engage but if it did, weee. It wouldn't be the thing breaking.

The new style viscous coupler sends power to the wheels that are not gripping right? So yeah, it would probably make the PTU and rear end much happier but I wouldn't be so happy. Somebody here needs a 9 second car on street tires :P

[Aries_Turbo]

i dont think the differences are quite what you describe. both systems are supposed to have a viscous coupler. whats that housing right before the driveshaft goes forward.

that vac stuff was supposed to be just for reverse i thought.

Brian

[zin]

i dont think the differences are quite what you describe. both systems are supposed to have a viscous coupler. whats that housing right before the driveshaft goes forward.

that vac stuff was supposed to be just for reverse i thought.

Brian

This is what my understanding is as well. The dog clutch is engaged when in reverse via the vacuum motor/solenoids. The big coffee can looking thing on the front of the early rear is the viscus coupler, at least as far as I can tell. I have yet to break it down to inspect each component.

Mike

[Ondonti]

i dont think the differences are quite what you describe. both systems are supposed to have a viscous coupler. whats that housing right before the driveshaft goes forward.

that vac stuff was supposed to be just for reverse i thought.

Brian

Do you see room for a viscous coupler anywhere?
If it had a viscous, then there was really no point for this part since the later version obviously doesn't have it.
http://img401.imageshack.us/img401/2087/img3814jz4.jpg
http://img136.imageshack.us/img136/4594/img3816pq4.jpg

[Aries_Turbo]

not in there goofball. the thing at the end of the torque tube like mike said.

Brian

[black86glhs]

Actually, between the diff and the actuator opening is enough room. I thought the item in front of the torque tube was a c/v joint.

[zin]

Actually, between the diff and the actuator opening is enough room. I thought the item in front of the torque tube was a c/v joint.

There is a flange for the drive shaft to attach and it has what looked like a CV joint rather than a simple U-joint. What I expect is the viscus coupler is the coffee can looking thing that the drive shaft attaches to.

Mike

[black86glhs]

There is a flange for the drive shaft to attach and it has what looked like a CV joint rather than a simple U-joint. What I expect is the viscus coupler is the coffee can looking thing that the drive shaft attaches to.

MikeYour right, I missed the C/V joint after the K frame. That can is the viscous coupling.

[Ondonti]

Anyone have any breakdowns on viscous coupler insides?

What exactly is the point of the clutch?
Other AWD vehicals dont have one...

[Aries_Turbo]

other awd vehicles have a center differential. the van doesnt. in the dry, youd be lurching around corners like a 4wd pickup and breaking stuff and wearing out your tires with no viscous coupler.

Brian

[Garffus]

hahaha! man! all the gear and no idea! hahaha!

a viscous coupler...http://217.34.53.228:9876/uploads/flvc1.jpg

yeah, the lump just forward of the rear case, Brent you crack me up :lol: phh, you’re lucky to have Brian to keep you in check...

Brent, seriously now, the viscous coupler is much like a torque converter for an auto box. It uses a series of disks with holes in very close together; half connected to the input, half to the output, but not touching and is filled with silicon oil as the resistance. normal driving with no slip means the silicon will transfer X amount of torque through it from the engine prop depending on its viscosity, but silicon goes hard when worked/heated which means that if a front wheel were to slip, the VC would see a differential in speeds and would work the silicon through the disks making it hot and go hard, which will have the effect of making a solid drive, thus, when slip occurs, the coupler quickly eliminates this by diverting the torque equally between the axles. Furthermore, the best bit is if you were so say change the silicon oil for a slightly heavier version, you can go from say, 60/40 front/rear to say 50/50... or any combination in between which means once set up, we can modify our AWD to whatever needs we may have at many transmission shops.

sorry if this is patronising to some, but it is clear many do not know what a VC even looks like, let alone what it is or how it functions and these are the forerunners of our awd TDs. Anyway, kudos to you Brent for getting stuck in and getting it done!

[Aries_Turbo]

you know what would be a cool test as well. get an extra viscous coupler from the JY just in case.

remove the front axles and plug the holes. go around and beat the living crap outta the car/van/whatever and see how much abuse that coupler can take before it starts slipping alot/the fluid gets too hot/any failures occur. then let it cool down and see how long it takes before you can start moving again.

that will tell us how long one of these setups would last on say a road course or a rally stage or whatever.

yeah the coupler is going to take alot of the shock out of the rear driveline as its progressive and not like a clutch going "BAM!" when you drop the hammer.

i wonder how long it will take before we have to change the fluid.

I have some parts lined up from a 2001 caravan. i should be going to get them early dec. then next spring, ill be starting my fab work.... that is unless by some miracle, i get my garage cleaned out and organized. :)

im going to have to deal with the lack of a speedo drive. ill probably swap a stock speedo in there from the 89 GTC dash panel cause it was an electric driven speedo and ill either use the entire dash panel or just swap the speedo into my K car dash panel and probably install a VR sensor in one of the diff housings to take a reading off of the ring gear bolts or something and dream up some electronic brain box to drive the electronic speedo. that shouldnt be too bad i dont think. i can probably use the sensor off of an intrepid bellhousing that reads the flywheel or the one off of the back of a neon motor/2.4L.

if i was really ambitious, i could have the "brain box" drive a stepper motor to spin a speedo cable as well but we'll see about that.

when that goes down, ill detail the process.

Brian

[Garffus]

you know what would be a cool test as well. get an extra viscous coupler from the JY just in case.

remove the front axles and plug the holes. go around and beat the living crap outta the car/van/whatever and see how much abuse that coupler can take before it starts slipping alot/the fluid gets too hot/any failures occur. then let it cool down and see how long it takes before you can start moving again.

I like that idea, if someone was savage enough to put their coupler through the abuse..

The one pictured is from a freelander, ive changed countless ones of these, they are a weakspot on them if your running much more than stock power and really use them hard off road.

[Ondonti]

hahaha! man! all the gear and no idea! hahaha!

a viscous coupler...http://217.34.53.228:9876/uploads/flvc1.jpg

yeah, the lump just forward of the rear case, Brent you crack me up :lol: phh, you’re lucky to have Brian to keep you in check...

Brent, seriously now, the viscous coupler is much like a torque converter for an auto box. It uses a series of disks with holes in very close together; half connected to the input, half to the output, but not touching and is filled with silicon oil as the resistance. normal driving with no slip means the silicon will transfer X amount of torque through it from the engine prop depending on its viscosity, but silicon goes hard when worked/heated which means that if a front wheel were to slip, the VC would see a differential in speeds and would work the silicon through the disks making it hot and go hard, which will have the effect of making a solid drive, thus, when slip occurs, the coupler quickly eliminates this by diverting the torque equally between the axles. Furthermore, the best bit is if you were so say change the silicon oil for a slightly heavier version, you can go from say, 60/40 front/rear to say 50/50... or any combination in between which means once set up, we can modify our AWD to whatever needs we may have at many transmission shops.

sorry if this is patronising to some, but it is clear many do not know what a VC even looks like, let alone what it is or how it functions and these are the forerunners of our awd TDs. Anyway, kudos to you Brent for getting stuck in and getting it done!

I was referring to driving in reverse, not what at viscous coupler actually does. Whats so special about reverse?

[Ondonti]

http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3825.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3824.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3823.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3822.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3821.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3820.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3819.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3818.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3817.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3816.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3815.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3814.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3813.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3812.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3811.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3810.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3809.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3808.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3805.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3800.jpg

[Ondonti]

Here are the pics from when I took the thing apart. Trying photobucket now and I love it. This would have taken an hour on imageshack.

http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3798.jpg
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/IMG_3796.jpg

[Ondonti]

63" wide at the rear end from the mating surface of each axle.
119" long from PTU shaft to center of rear end.

[Reaper1]

Good pics! The rear diff doesn't actually look all that bad. It's so tempting to think(I didn't study it that hard mind you) that you *may* be able to use one of the front diffs back there! That would be pretty sweet!!

[Ondonti]

No real active AWD threads going on so I bought up this old one.

Picked up what I call the AWD holy grail, the AWD diff that has the small driver side bearing. That and another T case.
Now I have

2 speed sensor transfercases
2 non speed sensor transfercases.
6 long passenger AWD specific axles (2 styles)
2 double large bearing AWD diffs
1 passenger side small bearing AWD diff.

I don't think I need anymore differentials because I don't think they will ever fail
I do want to pick up some more transfercases. There were 4 AWD vans in the yard today. Annoyingly they put the junkyard jacks on the K frames of each AWD van (but not some of the others) so even getting holy grail diff out was crazy dangerous. I would have not succeeded if I didn't want it so bad.

I pulled the tailshaft on this transfercase so I could avoid taking apart the K frame top brace. Inside you can see the teeth in the shaft that runs the speedometer sensor.

http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/SANY3606.jpg (http://s546.photobucket.com/user/ondonti/media/Caravan%20AWD/SANY3606.jpg.html)
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/SANY3607.jpg (http://s546.photobucket.com/user/ondonti/media/Caravan%20AWD/SANY3607.jpg.html)
http://i546.photobucket.com/albums/hh426/ondonti/Caravan%20AWD/SANY3608.jpg (http://s546.photobucket.com/user/ondonti/media/Caravan%20AWD/SANY3608.jpg.html)

[moparman76_69]

You don't want to sell one of the speed sensor PTUs do you?

[Ondonti]

You don't want to sell one of the speed sensor PTUs do you?

I plan on breaking these unless further notified by the power transfer unit. Having had the pinion off the speed gear version, the shaft inside has splines in it just like our normal passenger axles, just much larger diameter. Not sure how that works speed sensor gear wise.

[moparman76_69]

Both of my PTUs (transfer cases) don't have provision for the sensor. I would like to have one that does. I'd trade my other non vss one for one that has the sensor. I'd like to keep my stock speedo working.

[Ondonti]

I am in the same boat as you but since I don't know what fails on these things in racing conditions (could be the shaft) I wouldn't let my backup parts go. I was planning on using a GPS sending unit when I only had a non speed sensor PTU in my collection.

[moparman76_69]

Yeah I was hoping to be able to keep the vss connection to the smec. I dissassembled the ptu thinking it might have the grooves cut just not have the boss machined out in the case, but the shaft didn't have the speedo gear cut into it either.

[Reaper1]

I wouldn't go with a GPS based speedo, personally. Now keeping in mind I've only had 1 personal experience with them, and they were fairly new and it was on a bass boat, this is what I saw:

While sitting still or moving slowly it worked fine. On hard acceleration it was jumpy where it couldn't keep up with what was going on...like the refresh rate wasn't high enough. At high speed it would loose its link and stop displaying any speed.

Now, on my phone GPS I don't have these issues, but I think it also uses cell tower triangulation to fill in the gaps in the link (like old LORAN systems).

[Ondonti]

I had researched it quite a bit and even found HUD units that also have an output for running another speedo or sending to a computer etc. THey are a bit more common these days as they now sell electronic aftermarket speedometers. The good ones are 10 updates per second. I think thats the fastest I have been able to find that has an output.

I have had good success with cars not having VSS hooked up to the SBECII computers but still driving the OEM speedo. No stalling problems when everything is functioning on a manual transmission car.

[cj011]

I am just tossing a random idea out there. Why not run a 1 piece drive shaft straight off the PTU and replace the rear with a ford 8.8? Will it cause too much binding?

[zin]

The gear ratio id dictated by the diff, so custom gears would be needed at a minimum, but anything is possible, just might not be the most economical.

Mike

- - - Updated - - -

The gear ratio id dictated by the diff, so custom gears would be needed at a minimum, but anything is possible, just might not be the most economical.

Mike

[Ondonti]

I am just tossing a random idea out there. Why not run a 1 piece drive shaft straight off the PTU and replace the rear with a ford 8.8? Will it cause too much binding?

I have a 7.5" GM rear end with the proper ratio and the only upgrade I know of would be an 8.5 GM. I would not say there is a lot to be gained, especially with the weak 7.5 that I picked. Its possible the OEM rear end is junk or possible it can hold ridiculous power. The 3000gt rear end can hold up against pure RWD supercharged 440ci Mopar making near 1000hp. That makes zero sense why it can do that when the stock output is about 110whp to the rear when in 50/50 torque split.

[c2xejk]

No real active AWD threads going on so I bought up this old one.

Picked up what I call the AWD holy grail, the AWD diff that has the small driver side bearing.

So what vehicle did you get this from?

[Shadow24]

Yes, please, what year/model is this more adaptable setup from?

[Ondonti]

So what vehicle did you get this from?

It might be impossible to tell. Speed gear transfer cases are rare, possibly only 1st year, and I have two, but only 1 small diff bearing.

[moparman76_69]

My diff came from a 93 caravan and had the small bearing. I didn't realize at the time it was different that what others were seeing.