VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 u-joint ball housing

I am (still) working on a stock 1938 Chevy 1/2 ton pickup with the stock closed driveline. I'm getting ready to put it back in, but am wondering if I should replace the u-joint ball housing and rear transmission case/ball seal. I have read that these become worn and vibrate a lot in low gear and reverse, not to mention leak a lot. Has anyone had any experience with this? Is it common? Is there a way to check the ball housing to see if it is worn enough to cause a problem?

Also, which is better...a cork ball gasket seal or rubber?

Finally, are there brake master cylinder rebuild kits that are incompatible with silicone fluid?

Thanks

chevtrkmn

If the brake kits are of recent manufactor (last 20 years) they will handle Silicone fluid.If there older than that I wouldn't bother installing them for any fluid.Always use fresh rubber brake parts.

You can see if the ball and/or housing are woorn.The area where they make contact will be worn and pitted.Some were is normal and proper fitting is necessary.If you can find new parts in this area I would suggest replacing them.They do show up on Ebay and sell for a low cost usually.The paper gaskets (shims) (round with 4 holes) dtermine how "tight" the ball fits to the housing.Should be tight enough for movement but loose enough to allow ball to move up and down with the torque tube.The drive line vibration comes more from the bushings inside the torque tube.If they are worn the drive shaft will whip and vibrate in them.One bushing rides on the rear yoke of the U joint and one on the front of the drive shaft - just behind the front one.They usually don't cause clutch chatter - but general loosness in other ares can.They had some chatter when new (Chevrolet called it transmission gear rattle) and we would run #140 gear oil in the transmission in the summer time to help eleminate it.
The original gaskets and cork seals, worked fine when new.Some of the seals made today are too hard, etc. and can cause some leakage.A little seepage could be called normal.

Thanks Chevgene

I think I'm going to replace it so I don't have to worry about it. I've never driven this truck...it was a basket when I aquired it...so I don't know if it ever chattered. I already went through the flywheel, clutch, transmission, u-joint and driveshaft bushings. Sounds like the advice I got earlier was wrong anyway...the vibration I heard described for these trucks does not come from the u-joint ball housing. Still, I don't want to have large amounts of oil leaking around the seal because my old part is grooved and/or warped. If it does, it's a bit of work for me to replace it later. Which is another point I wanted to bring up...does this sound right to you? I've got a four speed transmission and I can't split the u-joint while still in the tranny case...not enough clearance. I have to remove the rear end from the springs, pull the whole thing back which removes the driveshaft from the rear yolk of the u-joint. Then I can remove the joint from the tranny by removing a bolt with a deep socket on a long extension from the tail shaft of the tranny. That single bolt holds the front yolk of the u-joint to the tail shaft of the tranny. I have the shop manual which decribes removal of the u-joint for the larger trucks with a four speed and two piece drive shaft, but not for a 1/2 ton with four speed. The manual also says that a four speed could be ordered from the factory for a 1/2 ton truck, so I think the tranny belongs there...although I have not verified the numbers. Since my truck has a single shaft and only one u-joint, I can't figure out any other way to get it apart. There just isn't enough clearance to split the u-joint while it is still inside the rear transmission case and the only way I can see to remove it is by removing the drive shaft. So, I would have to repeat this whole process later in order to replace the ball housing and/or gaskets and seal if it leaks. Am I doing something wrong or has my truck been modified in the past?

Thanks for the continued support.

You will have to slide the rear axle asm. rearward to allow enough clearance to remove the "U" joint. The 1.5 ton you can remove the center shaft support and center shaft to get it out. The 1/2 ton could be ordered with the 4 speed transmission

On silicone brake fluid, I wrote some articles in G&D some years ago, and more recently in VINTAGE TRUCK. the bottom line is 'Raybestos' brand gives a guaranty their cups are compatible with their silicone fluid. NAPA also used their BPI parent, Brake Parts International, so NAPA elastomers should be compatible. I believe the Vintage Truck articles are on my website.
Bob ADler
Adlersantiqueautos.com

Thanks for the advice.

Silicone brake fluid meeting Dot 5 specifications will be compatible with the natural rubber brake parts. All Dot brake fluids must have acceptable swell with the rubber brake parts. I could write an article (once worked in the Automotive department of the worlds largest supplier of brake fluid) on brake fluid. We did most of the testing on the first silicone brake fluids which were developed by Dow Corning. Also some of my compatriates worked on the SAE Committee that developed the Dot 5 specifications.

Thanks

Chevtrkmn