Should I make the diff use its own oil like they used to?

[turbovanman²]

I am putting my trans back together and now is the time to make it so the diff has its own lube, just like in the old days. So, should I do it? I am running an OBX so ripping out spider gears isn't a concern but I would be able to use a nice synthetic gear oil in there, :thumb:

[Boogieman142]

i would

[Clay]

the gears and bearings in that system are designed to run on the lube called for. You could have issues running a much thicker/heavier lube in a system designed for something else.

[boost geek]

Roller bearings are used in multiple applications, some of which use grease. The bearings dont differ in material, just different sizes. I know you have an auto, but I believe many 5 speed cases would be saved with gear oil, as usually the same bearing always seems to go, and eventually spit out the case. Did your bearing blow beside the pinion gear, or is it too munched to tell? That could explain how you ripped the teeth off the gears if that bearing had a sudden failure. Using ATF or even 5/30 is mighty thin, works for synchros, but not much cushioning effect on bearings.
I know you already know about thin oil, and that's why your thinking about gear lube. I dont know how you can do it, but you do, because hey, YOUR THE TURBOVANMAN, and if you can make it work, go for it! Your diff bearings and gears will love you for it!:thumb:

[turbovanman²]

I put brand new bearings on the diff when I put it in and they have some serious wear on them, they look like they've been in there for years. I haven't got the output shaft out yet, probably in a few days.

Clay, trust me, gear oil won't effect the LSD and it will probably cushion the bearings nicely. I have made up my mind, if i can the required piece for the output shaft/transfer shaft, I am going to do it.

Anyone know how far the level goes, I have to make a fill/level plug in the diff cover?

[Clay]

hey, go for it!! I think if it works (which is probably will) it will be the better setup for the diff and the bearings.

All Im saying is that some bearings internal clearances can be made looser/tighter for the application they are used in. 'bearings are all the same' is a little off base.

[looneytuner]

Ask SMP. I kthink he has the answer. One turn with all those pieces in there would wipe out a bearing.
There is Hemi Anderson on the TC site. When he buys a used Turbo car, he cleans the engine by running atf for x miles in the ENGINE. His car has 255,xxx miles on the original engine.
I think maybe REchecking the preload after running. Maybe gentle break in for the diff. (well that's too late) If anything, the chinese gears got pollished and the preload was not enough. Just a thought. Where did all the excess crap that got polished off the OBX go?

[turbovanman²]

Ask SMP. I kthink he has the answer. One turn with all those pieces in there would wipe out a bearing.
There is Hemi Anderson on the TC site. When he buys a used Turbo car, he cleans the engine by running atf for x miles in the ENGINE. His car has 255,xxx miles on the original engine.
I think maybe REchecking the preload after running. Maybe gentle break in for the diff. (well that's too late) If anything, the chinese gears got pollished and the preload was not enough. Just a thought. Where did all the excess crap that got polished off the OBX go?

Even with the open diff, those pieces still float in there so thats not an issue.

[86Shelby]

How are you planning to go about this? Find a seal or two that will seal very well on the output shaft and then machine the case to accept the seals?

Might do you good to work in a vent cap of some sort for the diff cavity so pressure doesn't acidentally overcome whatever you use to seal it from the rest of the trans once it's all good and hot. I doubt gear lube will work very well in a converter or valvebody.

For the level I would take a cue from level of the fill plug on manual transaxles and other differentials. Possibly take notes from a PTO/transfercase/rear diff unit off an AWD Chryco minivan or an old AWD Pontiac 6000 for starters.

[turbovanman²]

How are you planning to go about this? Find a seal or two that will seal very well on the output shaft and then machine the case to accept the seals?

Might do you good to work in a vent cap of some sort for the diff cavity so pressure doesn't acidentally overcome whatever you use to seal it from the rest of the trans once it's all good and hot. I doubt gear lube will work very well in a converter or valvebody.

For the level I would take a cue from level of the fill plug on manual transaxles and other differentials. Possibly take notes from a PTO/transfercase/rear diff unit off an AWD Chryco minivan or an old AWD Pontiac 6000 for starters.

Well, from 78-82, they had a oil pump gasket that blocked off the open area if it wasn't machined open at the factory, at the transfer shaft-aka Pinion gear, this one step one. Step 2 was the transfer gear bearing retainer, this had a seal on it to yep, seal it off. I can still get that retainer, theres one left and the seal is local stock. Step 3 was a vent in the speedo housing, so that part is easy. I would still need to weld up one hole in the diff, near the top.

BUT, I ran into a big obstacle, they don't make the oil pump gasket thats NOT cutout to lube the diff, so I have 3 options-weld it shut, make my own gasket or forget about it. I am going with the latter, tired of it sitting at my shop, dead in the water.

[Clay]

fill level is easy. Fill to just below the centerline of the ring gear.

Thats the "rule of thumb" for submerged lube systems.

[Clay]

so I have 3 options-weld it shut, make my own gasket or forget about it. I am going with the latter, tired of it sitting at my shop, dead in the water.

Go to your local industrial supply house and get some gasket material. Easy 'nuff.

[Tony Hanna]

I may be way off base here, but when you get this up and running Simon, you might consider a good "climbing" gear lube or a little of the Lucas additive in with the regular stuff. That stuff really does wonders at making sure the lube gets everywhere it needs to be. I like it especially in lifted trucks where the housings have been rotated to get a decent matchup to the drive shafts.
In cases like that the pinion bearings can starve for lube. The lucas stuff goes a long way toward correcting that.
Just thought I'd throw that out there for you to think over.

[Tony Hanna]

Also, you do realize we expect a full write-up with many detailed pics and a complete parts list if you get this working right?:p

[Frank]

I say leave it the heck alone. Get the dang thing running! ;)

[turbovanman²]

Also, you do realize we expect a full write-up with many detailed pics and a complete parts list if you get this working right?:p


I am not going to bother Tony, I don't feel like making a gasket and the bearing housing is a week away. I guess I should have done this awhile ago but you know how it goes. I will go full Amsoil again.

[Tony Hanna]

I hear ya. Might be worthwhile to test it out on something other than your daily driver/race car anyway. Sounds like a good winter project.

[Frank]

Since you have an old tranny now... I need a clip that sits about halfway down the main shaft right after the last clutch drum.


Frank

[turbovanman²]

Since you have an old tranny now... I need a clip that sits about halfway down the main shaft right after the last clutch drum.


Frank


Got a pic for me, I don't quite now which one you mean!

[Clay]

lucas oil addative is junk......... I wouldn't put that stuff in my friends buddies junk lawnmower.

[Tony Hanna]

lucas oil addative is junk......... I wouldn't put that stuff in my friends buddies junk lawnmower.

I wouldn't run the stuff in an engine I cared about, but from experience a little bit mixed in with the gear lube does wonders. Especially in a rear end with pinion bearing oiling problems like I mentioned in my previous post.

[TurboJerry]

Lucas oil stablizer puts an amazing *crud* on the valves/pistons that takes forever to get off. I don't recomend it. I do recomend something I mentioned in another thread. It works for 8 sec cars, and you can see the difference in the performance. I never found the need to do the separate oil thing. Eventually they *will* mix. I played with the og carb trannys and noticed this. Or there will be no oil in the diff and you won't know it. DOH!

[TurboJerry]

BTW I use 75/90 synthetic in the manuals, and I woulden't use anything else. It may be a little "stiff" when cold, but it's fine otherwise.

[turbovanman²]

Lucas oil stablizer puts an amazing *crud* on the valves/pistons that takes forever to get off. I don't recomend it. I do recomend something I mentioned in another thread. It works for 8 sec cars, and you can see the difference in the performance. I never found the need to do the separate oil thing. Eventually they *will* mix. I played with the og carb trannys and noticed this. Or there will be no oil in the diff and you won't know it. DOH!

What is it?

I ended up putting Amsoil full synthetic Dexron in again. It worked last time and I scored it free this time, :thumb:

[TurboJerry]

Put 1 to 2 qt of 15-50 mobil 1 in it. Gives a little more vescosity to help the bearings, but still allows for quick shifts. More than 2 will cause slippage *sometimes*.

[turbovanman²]

Put 1 to 2 qt of 15-50 mobil 1 in it. Gives a little more vescosity to help the bearings, but still allows for quick shifts. More than 2 will cause slippage *sometimes*.

Awesome, I will do that. :thumb:

Does it have to be Mobil 1?

[Una]

Put 1 to 2 qt of 15-50 mobil 1 in it. Gives a little more vescosity to help the bearings, but still allows for quick shifts. More than 2 will cause slippage *sometimes*.
In an AUTO tranny???

[TurboJerry]

It doesn't have to be M-1, but that's what I use in Mopar FWD auto transmissions. I'm sure other brands will work fine too........

[Tony Hanna]

That's interesting. I figured something as heavy as motor especially an oil as slick as synthetic would cause it to slip under a heavy load.

[turbovanman²]

That's interesting. I figured something as heavy as motor especially an oil as slick as synthetic would cause it to slip under a heavy load.

Why, I am using Full Synthetic tranny fluid and it barks 2nd gear like wouldn't believe, :thumb:

[Tony Hanna]

Yeah, but the tranny fluid should have an additive package (friction modifiers, whatever) designed to work with wet clutches.

[Una]

Well, toss normal motor oil like M1 into a motorcycle and the clutch in those works great (in fact, I've had a slipping one stop slipping with fresh oil in there).. Makes sense it might work well in a tranny as well.. I'd be more concerned about foaming..

[turbovanman²]

^^^Exactly, :nod:

[Tony Hanna]

Yeah, but when you think about it, The motorcycle clutches are designed to work with regular motor oil. They have to be since the same oil is used to provide lubrication for the engine, trans, and clutch. Let me put it this way, you ever ridden a bike with a worn clutch that slips a little? Dump the oil and go with something thinner and it will quit slipping for awhile. Go with a heavier oil and the slipping will get worse. This happens because it's harder for the springs to force the thicker oil from between the plates as the clutch engages. I'd have to think you'd run into the same problems with an auto tranny.

[TurboJerry]

Allison auto transmissions use 30 weight engine oil..... I had problems using synthetic trans fluid with a transbrake. It basically would not hold. Put Dex III in and it held. So I use Dex III, and M-1 and I think it's the best of both worlds. I know more than 2 qts will make it slip, so there is a threshold to how much......

[Tony Hanna]

Allison auto transmissions use 30 weight engine oil..... I had problems using synthetic trans fluid with a transbrake. It basically would not hold. Put Dex III in and it held. So I use Dex III, and M-1 and I think it's the best of both worlds. I know more than 2 qts will make it slip, so there is a threshold to how much......

I bet the Allisons run insane line pressure to handle it right?
I see what you're getting at now. Add enough to improve lubrication, but not enough to make a significant change in viscosity. :thumb:

[TurboJerry]

Now that you mention it........ Allisons are the firmist shifting "stock" transmissions as far as I know.