The Stovebolt Site Forums The Shop Area Driveline Transmission leak

Hey Guys, I posted this over on the HAMB, but didn't get the advice i was looking for. I've just copied and pasted it here, hoping to get better results.

1954 Chevy p/u. stock drivetrain w/ 3 speed manual transmission.

I've been trying to go through my truck and replace a bunch of gaskets to keep it from constantly "marking it's territory". I was hoping to get a little advice on one. I have a slow drip coming from the rear of the transmission. As I've done more and more research I think it's this location is technically part of the torque tube. This is my first project car, and I've never really torn apart a transmission before, nor had I even seen a torque tube before I bought this truck. Anyway. If you open the link, Fig 77. shows where the leak is coming from (drips from where the "G" is in "packing". Is it as simple as replacing the felt packing and washers? My understanding is that this part on the rear of the transmission is simply a housing for the U-Joint??? I have seen comments about transmission leaks allowing oil/fluid to leak down through the torque tube and into the rear differential. Is that even possible??!?!

http://chevy.oldcarmanualproject.com/shop/1954truck/54ctsm0448.html


Thanks

Bryan,

I could not get your link to work, but I think this is the page/photo that you want us to see:

http://chevy.oldcarmanualproject.com/shop/1954truck/54ctsm0448.html

If you are interested in obtaining that rubber seal, it is in this kit. I think that gasket/seal set is similar to Fel-Pro Universal Joint Set part # ES 72843.

Hy Bryan Buser, for some reason I can't open your link, but here goes. The joint between the transmission and the torque tube must be allowed to move a little bit as the rear axle moves up and down. To that end there are "shims" [thin gaskets] to adjust the tension on the joint. There is a cork seal near the o.d. of the bell, over the years of movement the cork can wear, and start leaking, removal of some "shims" will tighten this joint seal up and hopefully stop the leak. The procedure should be outlined in the maintenance manual that you can access through the link you posted. Yes transmission oil can migrate down into the rear axle, if the torque tube seal/bushing is worn, hope that helps.

Thanks for the heads up on the link. I've corrected it. Yes, I saw that gasket kit, but i guess what might clarify my concern is, is the U-joint ball normally supposed to have oil in it? or is it supposed to be dry? I can replace the gaskets easily enough, but if it's not supposed to have oil in it in the first place, then i need to replace some type of gasket or seal in between the transmission and the U-Joint ball. is that clear as mud?

Yes. It has lube from the trans. in it.

So, if the U-Joint Ball has lube in it, what prevents it from running down the shaft to the rear axle? The seal in the link above only appears to seal from the U-ball joint to the outside of the torque tube... If I could just find a good cutaway shot of this whole assembly, it would probably answer alot of these questions.

There is a bushing and seal near the forward end of the torque-tube. If the seal is still good, transmission fluid will not flow back into the rear end.

Seal: Group #5.469

If the bushing(s) and or seal is/are bad, an "Okie" bushing is a common repair/replacement.

Yikes!, that is one expensive seal... I don't imagine there is an easy way to tell if lube IS getting into the torque tube is there? That is, without tearing everything apart? LIke a drain plug in the torque tube?

Hy Bryan Buser, when you fix your tranny leaks and top up your trans lube, check your differential lube level and top up if required. Then take your truck for a couple of drives and recheck your diff. oil level, [make sure to check it at the same temparature that you filled it at] if the level is up in the diff, and down in the trans then the seal in the torque tube is leaking, hope that helps.

Thanks for all the help guys... it sounds like I have some work to do!

"Yikes!, that is one expensive seal..."

Bryan, you are NOT at the mercy of the antique car aftermarket suppliers. Seals are generic and are cataloged by size, ID, OD and thickness.

I recently changed the gearing in my '36 Chevy pickup using a '37 Chevy car rear end. While I had the rear end apart I replaced the original bushings with inexpensive OEM bushings from ebay PRIVATE PARTY sellers (not speculators/hoarders) and got a seal from a local bearing supplier.