VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Driveshaft leak

Hi, I know I am posting a lot of questions about my newly acquired Bel air but I am still waiting on the service manual. In the meantime, I am working through the bugs.
I notice a small leak coming from my driveshaft, somewhere about midway, near the emergency brake release spring. It looks like there is a seam there.
Any idea where the leak is coming from?

Not knowing the year of the Bel Air it is hard to accurately speculate on the source. Based on my experience most likely the leak is transmission fluid that progresses down the shaft until it is slung off. Any change from relative smooth cylinder will cause the lube to sling off.

Yes, that information would be helpful. It is a 1954 Bel Air, 3 spd on the column.

If it is a 1954 it should have an enclosed drive shaft.

There are 2 places that assembly could leak. One is the seal around the ball housing on the back of the transmission. The other is the packing seal where the tube from the transmission joins the larger tube that is attached to the rear axle housing.

The ball housing has to swivel within the stamped seal retainer as the rear axle moves up and down. The packing seal has to allow the inner tube to a telescope within the other tube as the axle moves up and down. The length changes slightly.

Great explanation. I would assume the oil that is leaking is from the 3 speed transmission gearbox in both instances?

I agree that most likely it is transmission lube. You should be able to feel the difference between it and engine oil.

I mention engine oil only because there might be a path from the engine to the rear. That is unlikely.

Here is the online manual. http://chevy.oldcarmanualproject.com/shop/1949_53/index.htm

Thanks!

I am going to replace both of the seals because I think they may be original.

Any idea where I can find these parts? I have been looking at Rockauto and Ecklers but nothing seams to match "seal around the ball housing and the packing seal."

Chevs of the 40's or The Filling Station will have these.

Thank you. How about the packing seal? I can not find any reference or find that item.

Unless I am missing something that kit includes the torque tube seal. It is the small diameter cork ring.

Rusty is correct. Kit contains all you need.

Thanks. You guys have been a big help. I have owned many cars from the 1960s but this is my first 1950s car. It is a little harder to find information on and locate parts.

DSVW,

Don't get your hopes up for a permanent fix here. Temporary slowdown is all you can expect. Get a pan for underneath the car and avoid new white looking driveways at your friends house or mansion if they own a Fleetline. Especially, circular driveways. It's a mystery but the spotting left by the transmission and mentioned parts, is much more pronounced when on new, white, circular driveways. Is too! Just park on the street (or anenue if your friend owns.. you know.

Best,

Charlie

Charlie is correct that while you hope for no leaks the best will be reduced leakage.

Charlie is also correct about checking where you park. When I have been invited somewhere that I do not want to be I do park in the clean driveway. I typically do not have to worry about being invited back there.

Ok. I have the flange and ball housing disconnected and pushed back on the shaft out of the way towards the rear of the car.

I disconnected the four nuts holding the universal joint in place and separated the joint.

I can not clear the housing forward of the universal joint to pull the ball housing and shaft straight off to change the cork gaskets. I tried to drop the axle a little but the emergency brake is in the way. I did remove the e-brake spring.

I tried moving the axle to the side but it won't move and I don't want to force anything.

Not seeing anything specific in my manual, am I missing something here?

Something that works for the earlier cars is to position the rear jack stands to hold up the the chassis, not the rear axle. That will allow the rear axle to hang lower and therefore, pull away from the end of the transmission, thus increasing the distance in the u-joint area.

Cheers, Dean

Dean’s approach has worked for me.

Some people suggest that you can loosen the u-bolts that hold the rear axle to the springs and slide the axle to the rear.

Most people let the axle tube rotate down. Then they pull the bell housing forward off the tube. On your car you might need to loosen the bolts that attach the axle to,the spring through the rubber bushing.

Remember that the weight of the car must be on the suspension when you tighten those bolts. Otherwise the rubber bushing is improperly pre-loaded.

Got it by jacking up the chasis. It looks like I will be using two shims (gaskets). I think that is what I took off, it was hard to tell they were so old. Does two gasket shims sound usual, I got 5 of them in the kit.

The key is that you want the cork seal in the external bell to fit tightly around the bell shield. It should take quite a bit of effort to move the bell tube. The kits have that many shims to accommodate the full range of fit between the parts.

The last time I sealed one of these I had to send a lot of time making the cork gasket fit properly. The one in the kit was way too thick. I hand sanded it down to the right thickness.

You also need to almost polish the surface of the bell. If it has any dents or rough spots where the cork seal rides it will leak or wear the cork away quickly.

I have everything ready to put back together but ended up hanging it up for the night. I spent the last couple hours trying to reconnect the universal joint. I just can't seem to make it happen. I have done a few universal joints in my day and never had a problem like this. It just doesn't want to line up. I have dropped engines in less time and while the service manual is full of good information, I don't find it very helpful but that is just me. Hopefully get it tomorrow!

Did you finally get the u-joint assembled? Whenever I was having trouble getting something to assemble my Dad would always say “You’re not holding your mouth right!”

Anyway , hope things are going back together.

Here is one other idea based on experience. I assume that you installed the new cork seal between the 2 steel washers on the front end of the driveshaft tube behind the packing nut.

Get a strap wrench to tighten that round packing nut. The cheap ones at Harbor Freight work great for this job.

You can try to tighten it with a big pair of adjustable pliers (Channel-locks) or a pipe wrench. But you won’t really get it properly tightened. The problem is that the thin round packing nut will deform due to the pressure in only 2 areas from the plier or pipe jaws. That makes you think it is tight. A strap wrench applies uniform pressure around that nut so you can really get it tight from compressing the cork seal.

Yes, I got around to it today. I needed some daylight and a break from the situation. Everything is back up and running and there is no leaking. I appreciate the guidance. I don't think the gaskets were ever replaced. It looked like someone had attempted to use a silicone type product to slow down the leaking around the bell instead taking everything apart, cleaning and replacing with new gaskets. The rear cork gasket was virtually non-existent.

My car is now completely leak free................for now!