The Stovebolt Site Forums The Shop Area Driveline Leaking Drive Shaft

I am finishing up the restoration of my 1950 Chevy 1/2 ton with a three speed transmission and have a small annoying leak of gear oil at the slip joint housing. I installed new gaskets in the ball joint housing and slip joint. It does not appear to be leaking at the ball joint housing. I am scratching my head trying to figure out where this leak is coming from as it would seem to me that if a seal in the transmission was leaking it would leak out the ball joint and I don't see how the gear oil could leak past the universal joint. Prior to the restoration I do not recall a leak at this location so I did not tear into the transmission and replace the seals in it. I have the original enclosed drive shaft and I am wondering if the leak may be from the rear end housing working its way up from there. I drained the transmission and measured 20 ounces oil which is a little less than what the drivers manual lists as it capacity. Any thoughts?
Thanks.
Mike

Fluids do not leak "uphill". Clean the front of the tube with the ball pivot ahead of the gland nut thoroughly, and inspect it carefully for a pinhole or a crack in the weld. Lube from the back of the transmission will be surrounding the U joint, all the way back to the seal in the Okie bushing a few inches behind that gland nut.
Jerry

Thanks Jerry for your reply. I am still trying to understand how GM designed the transmission/universal joint/torque tube to work. Is the transmission supposed to supply the universal joint with lubrication and the bushing in the torque tube (Okie bushing) to keep
It from flowing beyond it?

There is a seal built into the bushing at the front of the torque tube. "Okie" is a term for a replacement bushing built in Oklahoma that could be installed without disassembling the whole rear axle assembly. If the seal failed, transmission lube could run down the torque tube and overfill the rear end. Yes, the U joint and front bushing is lubed by splash from the transmission. Some transmissions have a pipe plug above the U joint where a little gear lube can be added on occasion to assure that the U joint gets adequate lubrication.
Jerry

I have the same transmission and had the same leak and it is definitely transmission oil. During my engine rebuild, I replaced the packing and gaskets during reassembly. I also cleaned the torque tube (including sanding) where the packing slides to enable the ball seal assembly to slide back far enough so it is spotless. I tightened the packing gland (collar), to where I felt it would be sufficient to stop the oil, but it was leaking following my first test ride. I snugged up on it again and it was still weeping. One more time did the trick. Trust me, its really tight.

I did exactly the same as you on the rebuild. All the gaskets are new and I thought tightened enough on the packing gland, but I’ll try to tighten it more. Thanks Phil.
Mike

Thanks again Jerry. There doesn’t appear to be any wear in the torque tube bushing as the oil is leaking before it and there is no scoring on the inside of the ball collar so my guess is I ether don’t have the collar screwed on tight enough or I have a crack in the ball collar or tube.
Mike

There is a procedure in the Chevrolet Truck Shop Manual for adjusting the universal joint ball seal to get the right fit. It’s tough to do while the engine and transmission is in but not impossible. Here is a link to the section of the manual that discusses it. You would need to drop the rear transmission crossmember to get the torque tube to drop enough to clear the tranny. [Link].

Should you decide that this adjustment is necessary, here is a link to a previous post that discuss’s the dangers of disconnecting the torque tube.[Link]

I recommend that you use a strap wrench to tighten the packing collar.

The strap wrench applies uniform pressure to the collar so you can really tighten it. If you use a pipe wrench or a large pair of adjustable pliers (Channelocks) you are applying pressure at 2 points on the collar. That distortion makes it hard to turn the collar but it really is not tight on the packing.

Thanks all for the recommendations. There is no leakage at the ball and I did follow the procedure in the shop manual for determining the number of gaskets, etc. There also does not appear to be any oil running down the shaft from the ball end to the packing collar so I am thinking I just don’t have it tight enough. Rusty, thanks for the recommendation on the strap wrench. I have only used a pair of channel locks.

There are two metal retainers between the quad seal, some times they are missing. (Mine were)

This is a common leak, Ive repaired mine and it will stop .....for a while.
There was a write up somewhere on this site that replaced the quad ring with on o ring.


I could not locate it.

The bigger the better. That is exactly what I used!

Looks like success! I tightened the packing gland nut with a strap wrench tight enough to spin the ball joint and no drip this morning. We will see after a test drive. Thanks again to everyone.
Mike

Glad to hear! Glad to help! With mine, as long as its only an occasional drip that I can wipe up with a rag, I’ll be happy. As least I’ll know it’s still got fluid, LOL!