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Grease leak at u-joint
Posted: Sat Mar 08, 2025 4:21 pm
by nathanw90
I inherited this 1919 roadster from my dad. Trying to stop, or at least reduce all leaks. So far I've resealed the inspection cover using aircraft sealant and neoprene/metal washers. No more drips there! Then the outside oil line and persons for the oil level with ezturn. Tightened up all the block to pan and hogs head bolts and cotter pinned. Sealed up gen mount, put one of those seals in the starter with a new busing and all new gaskets. Everything coated with aircraft sealant.
The one spot I cannot figure out is why a sliver of the grease hole shows at the top of the ujoint housing.
Grease just oozes out of here when running, driveshaft spinning.
The car has "float-a-ford" springs all around, but that doesn't seem to affect the height from the rear end. Any thoughts? Wrong rear leaf? Take a few leafs off? Any input is appreciated!
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 4:57 pm
by speedytinc
That is a tough area to seal or even slow down. But a constant ooze whall running points to possible reasons & ways to limit the leak.
One of biggest causes is a poor 4th main to output shaft fit. Clearance should be .0015" A missing output shaft plug can contribute.
A looser fit, thin & overfilled oil will allow oil past the shaft into the U-joint pocket. An exacerbator is the modern transmission screen which dumps its excess oil right on the 4th main. The 4th main has a lube hole on top. It can be rotated 180 degrees to limit some of the excess oil that comes from the screen. (If it was correctly center machined) & the pan is in alignment.
There can be excessive wear on the ball & flange fit. A shim is available to fill/take up for the wear. It is a ball joint & must be able to freely allow the DS to move up & down.
Use a thick grease.
I have tried a thin layer of ultra black under the outer edge of the flange.(Flange oil free) Run a small bead , let it set up an hour or so.
place in position to form the soft ultra.(Ball well oiled or greased) Bolt on with about a 2 thread gap. Let the ultra dry overnight. Snug home the next day.
This worked a few hundred miles, but eventually pounded out the sealer. So, I live with the ooze.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 4:59 pm
by big2bird
The quick answer is nothing you can do. There is no seal there, and no rear main seal.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 6:06 pm
by RajoRacer
With the T jacked up like it is, engage & disengage the handbrake as you would in normal driving conditions - look very closely at the ball socket for ANY fore & aft movement - could be a worn torque tube ball.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 6:36 pm
by Jerry VanOoteghem
Remove this gasket and it may help you some. Only 1 gasket is needed here, between the 4th main and hogshead.
Other than that... they just leak.
I will say, however, that your retainer ring kind of looks stretched out, letting ball go too far back. It almost looks like the lube hole in the ball is peeking out.

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Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 6:50 pm
by Allan
Jerry is correct about just one gasket needed at that joint, between the pan and the fourth main. However,I am not convinced that he is seeing an extra gasket there, just the back edge of the fourth main bearing flange.
If there is a gasket there, it opens up the ball housing, allowing excess movement and grease escape.
Allan from down under.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 7:07 pm
by speedytinc
Jerry VanOoteghem wrote: ↑Sat Mar 08, 2025 6:36 pm
Remove this gasket and it may help you some. Only 1 gasket is needed here, between the 4th main and hogshead.
Other than that... they just leak.
I will say, however, that your retainer ring kind of looks stretched out, letting ball go too far back. It almost looks like the lube hole in the ball is peeking out.
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Jerry might be on to something with the edge of the fill hole showing. I thought it was a bit of grease.
The hole may be uncovered by the frame being up on jack stands? It would appear so looking @ the wear pattern around the ball.
I first thought there was a gasket also, until I studied the different pix. I think its a clean 4th main edge.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 7:12 pm
by nathanw90
Jerry VanOoteghem wrote: ↑Sat Mar 08, 2025 6:36 pm
Remove this gasket and it may help you some. Only 1 gasket is needed here, between the 4th main and hogshead.
Other than that... they just leak.
I will say, however, that your retainer ring kind of looks stretched out, letting ball go too far back. It almost looks like the lube hole in the ball is peeking out.
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I will try this and report back.
I do have a shim on hand to try also.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 7:14 pm
by RecklessKelly
After filling the ball cap with grease, mine oozed grease out for a half dozen drives and then slowed right down. I wrapped a piece of oil absorbent mat around the bottom of the joint and tied it off with wire. I collect and reuse the exuded grease for my motorcycle chain. Would also be good for chassis joints as it has a little engine oil in it, making easy to push into the grease cups with a small syringe.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 7:15 pm
by nathanw90
Jerry VanOoteghem wrote: ↑Sat Mar 08, 2025 6:36 pm
Remove this gasket and it may help you some. Only 1 gasket is needed here, between the 4th main and hogshead.
Other than that... they just leak.
I will say, however, that your retainer ring kind of looks stretched out, letting ball go too far back. It almost looks like the lube hole in the ball is peeking out.
1.png
Wait, that you are pointing to is the 4th main. It's one of those sealed ball bearing units. This drivetrain was fully rebuilt a few years back.
What is between the cap and the bearing is a small bead of rtv.

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Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 7:35 pm
by speedytinc
If the DS ball was chopped/BUTCHERED per instructions, there is normally more slop added to the joint. A ball shim may help. Not a fan of the ball bearing conversion. Another repop part causing more problems than stock. IMHO.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 7:50 pm
by RajoRacer
Amen to that, John !
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 9:55 pm
by Jerry VanOoteghem
nathanw90 wrote: ↑Sat Mar 08, 2025 7:15 pm
Jerry VanOoteghem wrote: ↑Sat Mar 08, 2025 6:36 pm
Remove this gasket and it may help you some. Only 1 gasket is needed here, between the 4th main and hogshead.
Other than that... they just leak.
I will say, however, that your retainer ring kind of looks stretched out, letting ball go too far back. It almost looks like the lube hole in the ball is peeking out.
1.png
Wait, that you are pointing to is the 4th main. It's one of those sealed ball bearing units. This drivetrain was fully rebuilt a few years back.
What is between the cap and the bearing is a small bead of rtv.
IMG_1599.jpeg
Okay, that makes sense. I didn't know it had the ball bearing fourth main. I'm just seeing the edge of that.
Re: Grease leak at u-joint
Posted: Sat Mar 08, 2025 11:47 pm
by DHort
I wonder how many people have found much grease inside after they have separated the torque tube from the engine? Yes, the universal joint is greasy and the walls are greasy, but most of the rest of the space is just air. Ford only installed a grease cup there, not a zerk fitting. Even if you pump it full of grease, a month later you will find most of that grease is gone.
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 3:15 am
by Craig Leach
I'm going to go out on a limb here, we are dealing with 100 year old parts here that could not fit together well if they wanted to. If when
you grease your U/joint and that's how much grease comes out you have not greased it enough.
Craig.
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 10:24 am
by Jones in Aiken SC
Pump it full of a high temp grease after you go through the aforementioned fixes. High temp grease will resist dilution from hot engine oil that invariably seems to leak past the 4th main.
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 10:26 am
by Dan Hatch
Here is something that might help. There is a blue grease that is hard to thin with anything on the face of the earth. Leaking of oil from the 4th main wear is one cause of this leak.
This grease will slow down the leak, may even stop it.
I use it in all mine. Dan
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 11:40 am
by RajoRacer
If one enlarges the top photo, clearly seen is the wear pattern that John spied - no doubt the modification to a ball bearing 4th main has exacerbated the sloppiness in the unit thus the grease releasing !
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 12:45 pm
by nathanw90
RajoRacer wrote: ↑Sat Mar 08, 2025 6:06 pm
With the T jacked up like it is, engage & disengage the handbrake as you would in normal driving conditions - look very closely at the ball socket for ANY fore & aft movement - could be a worn torque tube ball.
Bingo. Moved forward quite a bit. Will try to install the shim and report back.
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 3:56 pm
by TXGOAT2
Be sure it isn't too tight. That will cause big trouble in a hurry! You don't want any binding, and no free play. Be aware that BADLY worn parts may bind when the car is loaded or goes over dips, and not when it is standing unloaded.
Re: Grease leak at u-joint
Posted: Sun Mar 09, 2025 5:56 pm
by troutjohn
Hi Dan, you mentioned blue grease in your post. Which one do you use?
Thanks. John
Re: Grease leak at u-joint
Posted: Fri May 30, 2025 2:55 pm
by skyhunter
For what it's worth I got an response from Lubriplate and their Max Tac Red grease is non-conductive (no moly or graphite) water resistant as there is no clay base and has a thick #2 lithium 'complex' and a melting point higher than the oil operating temp.
Re: Grease leak at u-joint
Posted: Fri May 30, 2025 3:27 pm
by TXGOAT2
If it doesn't ooze grease, it needs greased. No seals. About all you can do is get out and under and wipe the grease off once in a while. Don't overfill the engine with oil. A "diaper" of soft leather could be made up to help confine the grease. It would need lacing or some kind of snap closures to allow it to be removed and cleaned out from time to time.
Many old 4X4 front axles had a "closed knuckle" design at each outer end that was similar to the Model T u-joint ball assembly. They had seals or wipers of a sort, but most all of them that had been on the road much leaked.
Re: Grease leak at u-joint
Posted: Fri May 30, 2025 3:39 pm
by TXGOAT2
A butyl rubber football bladder might make a good boot or cover for a T u-joint ball.
Re: Grease leak at u-joint
Posted: Fri May 30, 2025 5:14 pm
by Norman Kling
Best seal is a round tail shaft and with the engine turned nose down the crankcase must be aligned so that the the 4llth main will slide up and down on the tail shaft when the bolts are started, The babbit must be snug but not binding. I have had no experience with the ball bearing conversion. Then when you grease the joint, be sure to use thick wheel bearing grease without any graphite or molybdnem which will foul the magneto. Just plain grease. Pump it as full as you can so the grease will act like a seal. If everything is right, you will have very minor leak at the u joint and engine oil will not run down the tube into the differential.
Re: Grease leak at u-joint
Posted: Fri May 30, 2025 6:38 pm
by Mark Chaffin
Once you put weight on the car, you will no longer see the hole.
Re: Grease leak at u-joint
Posted: Fri May 30, 2025 8:04 pm
by Allan
It needs to leak somewhat. If it is not leaking, the ball may not be lubricated all round, thereby accelerating wear. Just live with it, like owners of British motorcycles do.
Allan from down under.
Re: Grease leak at u-joint
Posted: Sat May 31, 2025 1:33 pm
by TRDxB2
nathanw90 wrote: ↑Sat Mar 08, 2025 4:21 pm
Grease just oozes out of here when running, driveshaft spinning.
The torque ball fits into the fourth main ball & ball cap. Its a simple ball & socket fit needing lubrication. There is no seal like for a CV joint.
The movement of the torque tube is bound to cause some grease to be squeezed out. The more wear in these parts, the more ooze of grease. But its good to see some ooze so you know things are getting lubricated. There appears to be a wear line on the ball end of the torque tube from its movement. I'll let others weigh in on the degree of wear. Suppliers have a shim to tighten things up, doubt if you need it because it may already be in use.
Re: Grease leak at u-joint
Posted: Sun Jun 01, 2025 7:25 am
by Jerry VanOoteghem
Mark Chaffin wrote: ↑Fri May 30, 2025 6:38 pm
Once you put weight on the car, you will no longer see the hole.
Bingo!