Greasing yoke on drive shaft.

[DmaxMad]

I have seen posts regarding greasing the yoke on the rear section of the dirve shaft.I think I read you put grease in it to help stop the jerk feel right upon take off from a stop. Is that correct? Mine has a rubber boot on it with crimp style clamps. Do you have to remove the clamps to pull the drive shafts apart? Or I am missing something on what needs to be done.

[turbowind]

I had the same problem over and over again, re- grease the yoke with all the special greases and techniques, and in time it the thump would come back. Finally a tech changed to GM syn. fluid in the transfer case and solved the problem.

Les

[DmaxMad]

Thanks. No Transfer case for me. I have a 2wd I should have made that clear in the first post.

[DmaxMaverick]

Originally posted by turbowind:
I had the same problem over and over again, re- grease the yoke with all the special greases and techniques, and in time it the thump would come back. Finally a tech changed to GM syn. fluid in the transfer case and solved the problem.

Les GM synthetic ATF? There is no such thing I've ever heard of. They do have Autotrac II fluid, which is for Autotrac 4x4. It may be fine at first in a manual transfer case (which is what you have, even if it is push button), but will kill it in a short time. I hope that is not what they put in your TC. They could have used Transynd, which is an Allison recommended synthetic ATF for the Allison tranny, that some dealers carry. Transynd would be a good choice for the TC.

I don't understand how a change of fluid types in your transfer case could help your issue. Perhaps if it had the wrong fluid in the first place.

[Jim Brzozowski]

DmaxMaverick Can you give more explanation on what would cause a failure in the transfer case by using the GM Blue stuff made for autotrac cases? Seems to me like a full time 4 wheel drive should be much harder on the transfer case than one you shift yourself. Just trying to understand whats going on. The GM dealer that sold me mine said it was synthetic and better for any case. Now what to believe???

[DmaxMaverick]

It is not a matter of one fluid being better, or more capable than the other. They are different because the design and operation of the hardware is different.

The Autotrac transfer case is a completely different animal than our "traditional" TC's. It is not just a gearbox. It has a torque sensing/balancing system that incorporates clutch packs like an auto tranny, or limited slip diff, if you will. The lubricating and friction qualities required by the fluid is very different, as are the operating temps. The internal materials the TC's are made of are also different. I don't know what is in the Autotrac II fluid that makes it so much different, but I do know if you use Dex III in an autotrac TC, it will not work, and will grenade in short order. If I had to make a guess, the difference would involve the friction modifiers required to allow the Autotrac to operate would attack the lubricated surfaces in a traditional TC. The Autotrac II fluid also has a considerably higher viscocity, which we know would not be friendly with the plastic lube pump, which already has issues using the correct fluid. The Autotrac TC has a positive displacement fluid pump, unlike traditional TC's.

[turbowind]

I am not certain what the fluid was...it is my hunch that it is the auto-trac which you have mentioned above....It has cured the problem and it has been in the transfer case for over 20,000 miles...It is time to change fluid now, maybe I better swap to another syn....


Les