33 Tranny to Driveshaft Oil Leak
 

Guys,
On my 33 Pickup I have a standard 3 speed tranny. Not sure what year the tranny is as it came with the truck but I believe its 33-47. Maybe someone can advise me on how to tell the year. Anyway, I'm chasing an oil leak. Oil is coming out of the output bearing, caged ball bearing, and into no mans land. See attached photo when I disassembled. This oil was able to seep through and leave puddles on my garage floor bad enough for me to jerk the rear end to see what's happening. When I look at some of the part catalogs I see a different type of output bearing, more like a sealed bearing than open ball bearing like I have. What's the secret to keeping this oil out of the area? I know there area gaskets for the u-joint connections and so forth, but I can't imagine that Henry would have allowed oil to just spill through the output bearing. Thanks for your help.
Peder

Re: 33 Tranny to Driveshaft Oil Leak
 

The bearing can be replaced with a bearing that has a seal on one side, the output side. You may have too much oil in the case.

Re: 33 Tranny to Driveshaft Oil Leak
 

Oil through the bearing helps lube the ujoint so new gaskets and seals are the best you can do.

Re: 33 Tranny to Driveshaft Oil Leak
 

Do you have the baffle in front of the rear bearing ?

The rear bearing is supposed to let some gear oil past like post 3 mentions .

I use SAE 140 in the u-joint cavity .

Re: 33 Tranny to Driveshaft Oil Leak
 

My guess is that you've over-filled the case. There will always be some oil coming through the ball-bearing, but that is more than I'd expect.

Re: 33 Tranny to Driveshaft Oil Leak
 

Are you sure it is comming from the transmission? Have you checked the oil levels in the rear end and the transmission? The joint cavity should be full of a thick oil. It is very common to have rear end oil migrate forward and drip at the transmission or even seep into the transmission. The back of tre transmission is usually covered with the heavy oil. It looks too clean to me.

Re: 33 Tranny to Driveshaft Oil Leak
 

FILL the U joint with at last a tube of high drop or drip point
grease. This stays stiff to make a seal and softens up as the
temperature from transmission heats up. G.M.

Re: 33 Tranny to Driveshaft Oil Leak
 

Is the truck lowered or raked? That is what causes the axle to trans oil migration. Big and little tyres add to the effect.

Re: 33 Tranny to Driveshaft Oil Leak
 

Put a bearing with a seal on the output shaft; fill the u-joint housing with JD Cornhead grease or the like... if the oil is coming from the transmission, problem solved.

The serial number is stamped on top of the clutch housing which will tell you what year transmission case you have... go to Van Pelt Sales to decipher the number.

Re: 33 Tranny to Driveshaft Oil Leak
 

Thanks guys much appreciated. Lots of good suggestions. Think I'll try a new output bearing with seal and see if that stops it from leaking. New gaskets of coarse. The front end isn't dropped but I am running quite large tires on the rear so possible that it is coming from the differential. I wasn't aware that I should fill the entire U-Joint cavity with grease. I can do that also.

Re: 33 Tranny to Driveshaft Oil Leak
 

Don't use a sealed bearing at the rear a small amount of oil should come through regardless of using a semi fluid grease.

Re: 33 Tranny to Driveshaft Oil Leak
 

Guess I just have to ask "why"?

Re: 33 Tranny to Driveshaft Oil Leak
 

Because a small amount of oil should be coming through its the way it was designed, the uni doesn't have rollers, oil is the best thing to get in there also it must help lube the torque tube bearing. Notice there's a seal on the front of the box not the back. This is not to say dont use some semi fluid grease, personally I dont go overboard with the grease others feel the need to pump it so full it would go back into the gearbox. I have had mine apart a few times now and all has been perfect from years of daily driving.

Re: 33 Tranny to Driveshaft Oil Leak
 

And I'll have to agree to disagree about this. Yes, you would get some oil leakage past the stock rear bearing with a shield which isn't going to hurt anything; as long as you maintain the oil level in the transmission. But; I'm not sure how well the GL does mix with the cylinder oil soda soap grease used in the U-joint housing. Not a desirable combination in my mind...

I put the half-sealed bearings in my transmission as recommended by "rumbleseat" many years ago; no problems, it will work.

Re: 33 Tranny to Driveshaft Oil Leak
 

And yet again this comes up . Pic is factory service bulletin for 1934 . The difference with the u-joint lube is it is thickened with tallow . Melts at the touch . Like REAL water pump grease . If your driveshaft seal is good and installed the proper direction and if you do a good job on the clam gaskets-speedo turtle gasket SAE 140 works great . Actually I use SAE 140 in the steering,tranny and rear also . BTW " low melt grease " like cornhead grease has a dropping point of 450 degrees . Cylinder oil with tallow thickener has a dropping point of about 95 degrees .

Check the rear baffle in front of the rear bearing .
It should be right against the outer race .
If this is not right way too much lube will get past .

Ford didn't think the design of this was bad as it never really changed thru 48 .

Re: 33 Tranny to Driveshaft Oil Leak
 

Guys,
I now believe the excess oil is coming from the rear end. Truck suspension is stock except I'm running 32" OD tires in the back and 28" OD tires in the front. The rear end is now disconnected so I can't tell how the drive tube angle will be until I reassemble everything. Do I replace the drive tub/drive line seal? It didn't seem bad when I had it all apart months ago. Lesson learned that I should have probably replaced it anyway. Or do I take out some gear oil in the differential? Thank you.

Re: 33 Tranny to Driveshaft Oil Leak
 

I think the only way to really stop this is to install one of the seals that is made to fit where the torque tube connects to the axle center section. This is an aftermarket part made to address this issue.

Here is one type, but there are other I believe.

http://www.seabrighthotrods.com/?p=522

https://www.jalopyjournal.com/forum/...stion.1057458/

Re: 33 Tranny to Driveshaft Oil Leak
 

I have roughly a 4" difference in tyre size but Ive never have the oil issue coming from the diff. I do have small ramps that I drive on when I park at home for the front.

Re: 33 Tranny to Driveshaft Oil Leak
 

Most of these original '35-'48 Ford banjo rears that I've torn down for various reasons over the years (and its been quite a few) have had bad axel housing and front of torque tube lip seals that needed replacing. Any of these rears I've rebuilt for my cars, and any of my friends cars, always get those three seals replaced with new.

Re: 33 Tranny to Driveshaft Oil Leak
 

There is not a lot of clearance betweeen the speedo drive gear and the snap ring. If you put something between the torque tube and the rear end, you cut down this clearance. How much clearance you have and the thickness of the new seal should be considered.
I would replace the stock seal. There is a trick to remove the bearing outer race. It is really easy with a simple to make tool. I also made an instalation tool from some conduit and a washer. You can drive the seal out easily but it needs a tool to put one back in.