The Stovebolt Site Forums The Shop Area Driveline help with leaking drive shaft?

I've got a 1953 3600 chevy truck. It has developed a lot of vibration at about 53 and above mph (I know, probably close to max mph, but with my '55 235 out of a bel aire that had a hydromatic and my 4.10 rear it used to do 55-60 pretty well. So after looking into this and thinking it's probably a front u-joint or a bad carrier bearing, We noticed it has developed a leak right at the carrier bearing. My mechanic is really good, 40 yrs+ experience. But he's never worked on something this old. Could someone steer me in the right direction as to how it leaks? is there a seal there (I assume there is) that could be replaced? And can a good mechanic fix it with some advice from you experts?

Please don't get mad at me for posting a question that's probably been asked. I did a search and I come up mostly with seal kits for the front bell housing (looks like that anyway) over the front u-joint. Some other articles I just don't know if they apply to me because I'm not sure how to explain it exactly (and I'm hoping someone on here can say - "duh, it's this"). Just a run down of how it leaks, how you fix it, or a link to a tech tip that talks about the seal (which I assume there must be due to the oil leaking).

Btw, I have a carrier bearing from O'reilly's. I saw them look it up and it said it's for a 53 chevy 3600, but if that's supposed to seal it I'm not sure how.

Again, please don't be short with me - I finally got my truck going and now I've run into this. Engines he knows. Brakes, trannys and the like he knows. But this he's never seen before.

Paul

Does the truck have the driveline with a short torque tube mated to the carrier bearing, and an open driveshaft behind the carrier? If so, it's possible for the seal at the front U joint to fail and allow transmission lube to run back to the carrier. The leak will be at the back of the transmission, not the center bearing. Check the lube level in the transmission- - - -it's probably low.
Jerry

Hi Jerry, It's been a long time.
It has the torque tube to the center carrier bearing and an open drive shaft from there to the rear end.
The oil that I can see leaking is definitely right at the carrier bearing. The "bell housing" or whatever it is at the front of the torque tube (or rear of transmission) does not seem to be leaking at all.

The mechanic is going to take a look at it today but I was hoping for some advice so he doesn't say "nope, not touching that". The guy is smart - he just needs some direction so he's not too uncomfortable to do it. How can oil leak at the carrier bearing?

Please, some advice?

I called you about the inline oil modification and I know you are a wealth of knowledge.

Paul

P.M. sent

Paul, Check out page 4-52 and 4-53 in the 1948-51 Truck Shop Manual for details on the front enclosed driveshaft on your 3600. It should be the same info for your '53. I snagged a pic from my book as the picture detail is a bit better than the on-line scanned pages. That pic shows the probable leaking seal location marked by the arrow in my pic below. The rest of that section of the Shop manual describes tear-down, inspection and reassembly.

According to the 1929-57 Chevy Master parts and Accessories book on page 477, the SEAL - RETAINER, Front Propeller Shaft Bearing for your '53 is GM# 3689176. My best guess is that seal is what is leaking, but there is probably something else worn (could be the carrier bearing) that is causing the vibration. Hope you find this helpful.

NOTE: Just some added info to what Jerry posted above

Gdads51, I have the chevy truck manual (I believe it says up to '51 with a supplement for '52) that I've been using. Would that be in my manual?

Yes sir! Page 4-52 & 4-53.

oops, sorry - I see you put the link on there

No problem!

Paul, If you need the seal, they can be found HERE for a reproduction one at a great price. If you want to shell out more money, there are a couple NOS seals on evilbay and another site, but expect some "sticker shock" with those asking prices. Ouch!!!

Just do a web search using GM# 3689176.

Your vibration may be coming from a worn bush where the front u-joint yoke rides. Once that wears out in will cause vibration and will eat that seal indicated in Dan's post for lunch. Once that happens, it will appear that the center carrier bearing is "leaking", when in fact there is nothing in that bearing to leak out.
The transmission is designed to allow fluid to flow beyond the front u-joint inside the ball to lubricate the u-joint and the yoke bushing. The rear seal is there to keep you from losing all of your transmission fluid.