The Stovebolt Site Forums The Shop Area Driveline Leaking 49 Chevy truck

Hi Fellow Members
I have a 49 Chevy truck 1/2 ton. I’m seeing a leak of oil coming from the drive shaft near the transmission. See the attached photo. The leak is coming from the area with sealant around it. Several questions. Is this transmission oil? Where would I add this oil? Is there a seal that can be replaced? How much of a problem is this? Any info is greatly appreciated.

"Is this transmission oil? Where would I add this oil? Is there a seal that can be replaced? How much of a problem is this? "

"Is this transmission oil?" - most likely (unless the rear torque-tube seal is bad)

"Is there a seal that can be replaced?" - the smallest ring-seal (rubber) in these sets, at least (the other seals/gaskets in the set might also be leaking).
https://www.classicparts.com/1935-54-U-Joint-Ball-Gasket-Seals/productinfo/92-111/
https://www.chevsofthe40s.com/detail/6244/Chevrolet_Transmission_Gasket_Set_3Speed.html

The Shop Manual describes the procedure (in Transmission Installation, steps 5. a-e).
You will have to open the u-joint cover, and disconnect the u-joint

if needed: u-joint assembly and lock plates/bolts Chevs of 40s
Classic Parts U-Joint
Classic Parts lock clip (you need two)
Classic Parts bolts - you need four

Even after a full rebuild on mine with new seals, I still get some seepage around the ring. Not a big problem really. This is a slip joint and must slide as the rear suspension articulates. So that goop on there as you see will never work. Open her up, clean, inspect, and reassemble per Tims links, and periodically check and retighten the ring.

** The operation you have been linked to is pretty simple and can be done in a couple hours. Be sure to order needed parts be fore disassembly. **

I agree with the above comments, especially Nhluvstruck, who states that even with a rebuild you may still get some seepage and also that the light colored goop will never work. Before tearing into the assembly why don't you try tightening the knurled ring with large pliers to see if that will slow the leak. That oil is from the transmission which is easy enough to check and refill.
Kent

I agree with the above comments, especially Nhluvstruck, who states that even with a rebuild you may still get some seepage and also that the light colored goop will never work. Before tearing into the assembly why don't you try tightening the knurled ring with large pliers to see if that will slow the leak. That oil is from the transmission which is easy enough to check and refill.
Kent

Try completely cleaning and polishing the outer surface of the torque tube before installing the new rubber seal (also, put a little grease on the tube/seal, before gently/snugly tightening the rear cap onto the bell/ball/cover).

Thanks for your advice. I’ll try tightening first. If not I’ll take it apart and change the seals.

The way that seal works is by compressing the donut seal near that collar. Tightening the knurled ring is what does this. It requires a large pair of channel locks to do it right. If it doesn't want to turn with relative ease, loosen it all of the way and slide it to the rear and clean the threads with brake cleaner and give it another go.
If it still leaks after that, the seal probably has a crack in it.
Carl

A number of us here are more concerned if that joint stops leaking.

Ok I’ll try that. Just wondering since I’ll have the truck on a lift, is there any chance the drive shaft will drop down if I loosen it?

As in, no more leak means no more fluid in there...where did it go?
Probably into your diff which means you need an Okie job!

No, the u-joint inside the ball housing keeps it together.

I was able to tighten a quarter of a turn.

What’s an okie job?

Cheap and dirty - git er done
(as per the poor depression-era Okie farmers (Grapes of Wrath) who had nothing and had to migrate from their worthless dust bowl farmland to poverty in California, etc.)

Robert, in this case, an "Okie job" refers to installing an Okie bushing, apparently so called because it was patented in 1946 by T.C.Gerner of National Machine Works, Oklahoma City. The prior post by NH suggested that the reason the transmission fluid stopped leaking out of the ball housing was that all the fluid drained out and was no longer there, that it may have drained down the torque tube (potentially overfilling the rear axle housing).

In case you aren't familiar, the Okie bushing assembly includes two bushings and a seal. It completely replaces the forward torque tube bushing and provides an additional rear bushing and the seal that keeps transmission fluid in the ball housing where it belongs. The repair bushing assembly was developed to be an easier fix than what the shop manual called for at the time - disassembling the rear end and removing the driveshaft - to remove and replace the two stock torque tube bearings and seal. The Okie bushing can be inserted once the forward bushing is removed, with the driveshaft still in place and without disassembling the rear end. Fixes both worn torque tube bushings and bad seal in one operation. Still available in three variants for different model years, from various parts vendors (sometimes misspelled as Oakie Bushing). See the image...

I thought it was sort of cool to see the original patent, which is here: Okie Bushing US Patent 2,403,520

https://www.classicparts.com/searchprods.asp

Search on: drive shaft bushing

A tool will also be displayed.
Maybe members will comment on the use/usefulness/necessity and ease-of-use of that installation tool?

photo of an original, packaged bushing

Thanks Doug of elaborating on my cryptic reference as I was on a 1200 mile road trip.... It is exactly what I meant!
Replacing this bushing was the single most exasperating job in my entire restoration.
The cheap tool is marginal at best, and I destroyed one completely trying to remove my old seized bushing. After a few unsuccessful attempts at making my own tool, I ended up making a small relief cut in the torque tube, lots of heat and penetrant, and a new tool later was finally able to get it out. Welded and finished the torque tube and the new okie bush went right in.
Next time I'll probably follow the shop manual approach, and hammer it out with a long pipe from the diff end.

Thanks Doug for a clear explanation of the seals and fix. Your response was terrific. The oil is still leaking despite my tightening the large flange nut.

I have had leaks several times from the same area. Each time I found the knurled nut needed to be tightened. Not sure if the seal was wearing or the nut just loosened over time. I remembered a tip someone once posted about using 2 hose clamps with a bridge between them that prevents the nut from loosening and I tried that the last time I tightened the nut. Very minimal leaking so far but I haven't put on too many miles since doing that. One hose clamp goes around the knurled nut, the other just forward of that on the ball tube. I used a slightly stepped piece of metal clamped between them thus preventing the nut from turning.

You are welcome, of course.

I have currently an Okie bushing for my '53 which needs to be installed. The rear axle was overfilled when I go it, and it appears that there is a slight leak at the right rear axle seal. I have the forward torque tube bushing removal tool - which is getting some pretty negative reviews, recently - and will try that before attacking the rear axle assembly for driveshaft removal. My prior experience was with the older dowel-pinned bushings, and removal of the forward bushing wasn't much of an issue. Just hoping I don't need to remove the driveshaft because of the press-fit torque tube bushing in the '53, but if I do, I will evaluate the driveshaft for wear to see if replacing the OE-style bushings and seal would make sense. Once an Okie bushing is installed, they are not easy to remove.