U Joint Lube
 

I have rebuilt my 1939 deluxe trans and in the process I degreased the u-joint attached to the rear of the trans. I believe this is a trunion type bearing (see pictures). Is this the case? If so, can i just lubricate with oil before reassembling the trans back in the car? If not, what do you suggest?

Re: U Joint Lube
 

I used sta-lube gl4 left over from my trans rebuild to pre-lube my ujoint. As this stuff is going to creep up into the ujoint anyway from the trans eventually, but I've been told numerous times to fill the ujoint housing from the grease fitting with dear John cornhead grease, I've picked that up but haven't filled yet

Re: U Joint Lube
 

I have been using cv axle boot grease. Napa has it in blister packages. Usually takes two of them. Figure its basically the same sorta situation.

Re: U Joint Lube
 

John Deere corn head grease or other semi-fluid type works very well for U-joints in the torque tube drive Fords.

Re: U Joint Lube
 

Several of you mention grease. The u=joint is not currently disassembled. There is no zerk fitting, do you mean to disassemble and grease? By the way, can someone explain how this unit is lubricated during operation?

Re: U Joint Lube
 

Thanks for the explanation. So at this point I should use some of the trans lube to lubricate the trunions on the u-joint to provide lube until the normal process begins.

Re: U Joint Lube
 

I thought that was what the hole in the inner cap was for.

Bob

Re: U Joint Lube
 

Try to find a old post by Dick Spadero ?? (Spelling ?). If you look at a Ford lube chart it calls for 600 wt mixed with soap grease(it keeps 600 from foaming? And injected into cavity. I think 4ozs. I have done this and used a cast clam shell with 1/8 pipe fitting on each 1/2 and put clear hose between the 2 fittings and filled with 4 ops. Don't use the cork. Find rubber hose that fits tight in the groove of clam shell it acts like a o-ring around the torque tube much better than cork. This way the u-joint is always getting lube.do not fill above parting surfaces. John. Ps I just used 140 wt grease from Speedway. Same stuff for Q-change.

Re: U Joint Lube
 

Dick had some great information on early FORDS!!!! He will be missed..!!!!!

Re: U Joint Lube
 

Ford used gear lube mixed with soda soap which was an early form of semi-fluidic lubricant. The JD corn head grease turns fluid with movement of the u-joint yokes then solidifies when the joint is at rest. This makes it more preferable than gear lube and soda soap mix. Gear lubricant by itself will usually find a way to leak out of the u-joint cavity and that was why Ford used the soda soap mix. Regular grease will be pushed to the outer periphery of the cavity under centrifugal loading and generally stay that way for the duration.

Servicing the u-joint is through the grease zerk fitting in the lower half of the outer ball cap. I agree that it isn't the best routing for service but if the outer cap lip seals will hold the grease in, it will make it's way around the tube bell and into the tube bell cavity where it will drool into the inner cap cavity. Your only other recourse is to pump some lube in there when the rear axle is out of the car for one reason or another and the inner cap is exposed.

The transmission rear slinger ring does a relatively good job of containing the lubricant inside the gear box. If the trans case is overfilled, the oil will seep through the bearing. Normal trans oil level will usually not allow this unless the car is parked nose up on a steep hill or something of that nature. You will get some case to cavity seepage but it shouldn't be much.

Originally the outer ball cap shells had a felt seal that compressed into the lip there. The modern cork stuff doesn't work as well. When the vehicle is setting dormant the fit in the torque tube bell area is relaxed somewhat and it allows for some lubricant transfer. A person can take the speedo drive housing off and watch for lube to come out at that location. That will tell you when to stop pumping or if lubricant is moving. That hole in the inner cap should be near the zerk but at a high enough level for grease to stay in the cavity.

Re: U Joint Lube
 

my inner cap had 2 holes in it at opposite sides just in case, i assume, you installed it or the outer clamn shell backwards to allow the grease from the fitting to get in there

Re: U Joint Lube
 

you can mistakenly order sealed bearings though.

Re: U Joint Lube
 

Tom W on the A board says to use a little grease. :D

Bob

Re: U Joint Lube
 

Rotowrench,
So again, I have an assembled u-joint, do I just smear the JD corn head grease onto the u-joint, if so approximately how much (thin coat, heavy coat, just on the ends of the trunions?). Or do I need to disassemble the u-joint?

Re: U Joint Lube
 

At least a tube if not more. I think this is one place that more is better
than not enough.

Bob

Re: U Joint Lube
 

Just squirt some GL4 over the joints let it rest then a light coating of semi fluid grease is all that's needed .. NOW while you have the trans at this stage with the uni tightened up check NOW where the oil baffle is sitting is it hard up on the rear bearing or is it just a tiny bit off as it should be? .. the uni should feel free when done up .

Re: U Joint Lube
 

☆Edit: after thinking a bit more about this last night, before I bolt the u joint to the transmission output shaft, I did apply some oil to the four trunions and bushings, allowing it to wick in, providing some initial lube to those bearings rather than starting them off almost dry. This does not require taking the u joint apart. Then I proceeded to apply the JDCHG as described below.

Yes, just smear the JDCHG all over the U joint. Some call this "buttering" the UJ. I apply as much as I can get on, in, and around the assembled UJ. Then when the inner cap, torque tube bell and clam shell halves are all bolted back in place, I pump more JDCHG into the torque tube opening where the turtle bolts on and in the zerk fitting on the clam shell cover. This will lube between the inner cap and the torque tube bell, plus it will push some into the U joint cavity thru the two holes in the inner cap. When I change oil and lube the chassis, I also pump a little JDG in the zerk fitting just incase some lube has leaked out of the UJ housing.

Re: U Joint Lube
 

Thanks to all those who took the time to supply answers.

Re: U Joint Lube
 

Assume your referring to the ISO VG scale which is ~140 gear oil on an SAE scale. Can you provide a reference to the Ford lube chart, thanks.

Re: U Joint Lube
 

The old manuals of the late 30s/40s just say steam cylinder oil & soda soap so a person has to assume they meant the old 600W. That has an ISO viscosity grade of 460 so it is near the SAE 140 mark.