1914 differential grease leak

Skolzie

Member
My differential grease is leaking from the U joint area. I rebuilt this unit some 40 years ago and somehow I can't remember where the grease seal is located. ?? Thanks much! Skolzie
 
Are you sure that engine oil has not gone past the 4th main and filled the rear end? What is the level of fluid in the rear end? Did you pull the plug in back to check?
 
The differential grease wouldn't be leaking from the u-joint area. :)
The u-joint housing is filled with grease and when the 4th main gets worn engine oil gets in to the housing and liquifies the oil. There is no seal in the area. I have used the old style wheel bearing grease which seams to resist the being liquified a little better.
The rear end should be filled with 600W or its modern equivalent not grease.
 
Hi, The diff. level was down to about 1/3rd. Filled same with 600W, and that what drips from U-joint is about the same consistency as the 600W.

Is old style wheel bearing grease available somewhere?

thanks, Skolzie
 
Yes any auto parts house should have it on their shelf. Yes it might have the look of 600W but if it was, it would have to work it's way up the drive shaft past the drive shaft bushing to drip out the U-joint.

Unless someone has filled the U-joint housing with 600W oil!

If that is the case you might pull the ball cap retainer back and allow the oil to clear itself then repack with a good non graphite type grease.
 
Does the driveshaft bearing in the diff, have a seal of any kind? Something that would prevent the 600W to follow up the driveshaft? It is my understanding that drive shaft, inside the torque tube, runs dry. Is this correct? thanks! g.
 
No seal at the pinion bearing of the diff. Rare to have rear end lube, heavy 600W to migrate up the angled torque tube to the u-joint. Most likely the engine oil is passing into the u-joint, caused by wear of the 4th main, or no oil plug in the driven shaft from the trans. or loose bolts at the u-joint to hogshead allowing grease and oil to leak out.

The u-joint needs to be packed full with wheel bearing grease, using the large grease cup over the ball joint. That will help prevent engine oil leaks. Don't forget to lube the smaller cup over the front driveshaft bearing with grease too. Any good wheel bearing grease is fine, the heavy red stuff is nice.

Many times with large engine oil leaks thru the u-joint into and down the drive shaft, will thin out the rear end lube, and overflow the carrier, and go out the wheels if seals on the rear axle are poor.
 
Just re-packed the u joint with some good thick wheel bearing grease. By forcing it in, it purged the "oil" out, so I should have it almost solid grease.

Will give it a test run in the next couple of days.

What is the makeup of the drive shaft, and its bearing, that connects the u joint to the trans.? You mentioned a plug. I'm looking for a way that oil, if splashed on that area, would drain to the u joint area. I mention this because at the beginning of this season, I installed one of those transmission oil screens. I visualize the oil draining through the bottom end of the screen, being just above this shaft/bearing assembly. I didn't have this oil problem until I installed the oil screen. Any thoughts on this?

thanks much! g
 
I had exactly the same problem after installing an oil screen. Take the screen out & the leak will stop. That does not mean there is not a problem in the 4th main area.
 
There's one thing not mentioned yet that commonly creates problem in the area - there should be a gasket between the fourth main and hogshead/pan but not between the fourth main and the ball cap. An extra gasket would add play and increase leaks. If the ball on the drive shaft is very worn, shims to take up the play are being sold at the vendors. The transmission screen is a good accessory that picks up most foreign objects from the oil and stops them from plugging up the hard to reach internal oil line.

If the fourth main leaks excessively it's probably worn out and should be rebabbitted, but if the play is reasonable and it should be useable for another season, then it can be turned so the oil feed hole is pointing sideways instead of upwards - might reduce the leak.
 
After packing with "red" grease, the oil leak stopped. Not many miles as I don't do much other than car shows, right now. The grease is "ozeing" out of the universal cap area, and the diff has increased it's leak speed. I don't believe the diff leak is relative to the oil leak problem at the u joint. ? thanks!
 
It's probably engine oil leaking into the differential and now that the ujoint leak is stopped, more engine oil is getting into the differential. This will thin the rear end lube and leak faster.
 
Where is the oil/grease leaking at the differential? The center or wheel ends? If it's at the center could be loose rivets holding the tubes on, if it's at the ends, could be bad seals at the wheel end bearing (both outer and inner seals) or over fill. If you have the 1914 rear end, the lube should be about an inch below the filler hole.
 
Diff leak(s) are from the rivets. (I did replace several many years ago when I replaced the gears, etc) The drip is not fast enough to really show a difference of fluid level, without measuring. As of now, I'll live with both problems for a while. I sure thank all who have replied, as I definitely learned alot. Thanks! Skolzie
 
The screen & band oiler puts way to much oil to rear of trans.Remove the screen and that oil leak will be much less.
 
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