The Stovebolt Site Forums The Shop Area Driveline How to get to ujoint

I took the four bolts out of the rear of the transmission and moved the cover back to reveal the ujoint. Now how do I get to it. Repair manual was pretty vague on it.

Scrape the grease off the torque tube all the way around and slide that collar and the ball back toward the differential. Once you do that you'll see 4 screws holding on the bearing/bushing caps (to the front yoke). Remove those and you should be on your way to disconnecting it. There are two bearings on the rear yoke which as I recall are retained by inside lock rings. Good luck!

You may have to unscrew the collar at the end. Sometimes those are sort of tight there. There should be a felt ring and one or two washers behind the collar part which will unscrew.

First- - - -call your insurance agent and make sure your life insurance policy is paid up. You're getting dangerously close to that torque tube slamming down and pinning you underneath it, possibly with some of the vehicle weight on your chest. That's especially true if you have the vehicle supported on jack stands under the rear end tubes. You need to have the frame rails supported so there's no weight on the rear axle at all. One of my friends from high school back in the 1960's was seriously injured by the situation I just described.

Once you have that situation handled, scrape as much crud off the torque tube behind the knurled nut on the pivot ball as possible, and "shoeshine" all the rust off the tube with a piece of emery cloth. You can then unscrew the nut with a big pair of Channel Locks and slide the ball back to reveal the U joint. Before you unbolt anything, support the tube with a floor jack to keep it from falling as you unbolt the four bolts of the bearing caps that hold the joint together.
Jerry

Jerry. Where are you saying to put the jacks. On the frame forward of the forward spring bolts was where I was planning to put them. Is that about right.

Anywhere under the frame, either ahead of or behind the springs. I prefer to put them closer to the rear behind the spring shackles, as I don't like a lot of weight hanging unsupported behind the stands and maybe making the vehicle unstable.
Jerry

My auto mechanics teacher in high school always told us to try and knock the vehicle off the jack stands after we placed them. If you couldn't do it, it was safe to go under. Any wobbble or movement meant jacking it up and starting over.

Jack stands can be placed directly under the springs between the u-bolts. A lot of jack stands aren't tall enough to get the wheels off the ground if under the frame. The plus side of having them under the springs is that they don't need to be extended so high and thus are in a more stable position. Pay attention to Jerry's suggestion on having something under the torque tube to support it. I have a scar to attest the the need for that.

Kevin, that method loads the torque tube downward with several hundreds pounds of vehicle weight since there's a pivot built into the axle housing mounts. It's not the same as supporting an open driveline vehicle under the springs. Disconnecting a torque tube with weight on it can get deadly dangerous.
Jerry

Trying to remember how I attacked my truck when dropping the gearbox and I believe I use to jack up the back end. Place floor jacks under the rear frame x2 behind the rear leaf spring coupling. Loosened the leaf spring U bolts. Placed another floor jack under the torque tube for support. Removed the rear gearbox cross member and it's connectors to the ball joint. Opened the ball joint, sliding the collar backwards after some good cleaning. Then disconnected the ball joint while again reassuring that I had a floor jack supporting the torque tube. Once disconnected I was able to raise the front end of the torque tube upwards until it contacted the bottom of the flooring.

I stand VERY corrected if I am forgetting something. It's been awhile.

Jerry, With the wheels off the ground, the vehicle weight would be on the springs when supported at the u-bolts, not on the torque tube, but there is a bit of force from the rubber in the pivots. If one were to loosen the pivot bolts, then there would be no force on the tube. The one that hit me in the head (on a '54 Station Wagon), dropped down and then rebounded up to a neutral position a bit below the u-joint. A ratchet strap over the top of the frame rails and under the torque tube should be enough to restrict it from moving, and could be used to jack the tube upward to allow removing the u-joint pieces.

But if the jack stands were to be placed on the axle, then yes, there would be vehicle weight forcing the torque tube downward.

Craig, there would be no need to loosen the spring u-bolts. But the loosening the pivot bolts would allow the axle to move easier.

Hmmm. What if I don’t jack anything up and just work with it that way.
Still going to put a jack stand under the torque tube.

Wouldn’t that be a neutral load on the torque tube?

Doug

What makes this more dangerous or different from a normal driveshaft? Is the rope drive torqued or under tension? Does it drop with a force greater than its weight?

That would work, but a jack might be better so you can move the torque tube up or down as needed to disconnect the u-joint. But the load on the torque tube won't be neutral because of the leverage from the pivot position (see below.)

The pivot point of the rear axle is forward of the centerline of the axle by a few inches. What makes it drop with more force than it's weight is the leverage of the weight on the rear wheels translating to a downward force at the torque tube, But like a teeter-totter that's short on one end, the long end of the torque tube needs less force to move the pivot. But if unrestrained, it would move faster than the wheels would rise relative to the spring mount point.
Also the rubber bushings are supposed to be neutralized (loosened and then tightened) with the truck's weight on the wheels and the u-joint connected. When the truck is jacked up by the frame, the wheels are unloaded, but the "spring" in the rubber pivot bushings is wound up from the axle dropping. That turns the pivot spring tension into a downward force on the front of the torque tube. If the torque tube is not supported, it can snap downward when the u-joint is disconnected. But it likely won't go all the way to the ground, and will probably rebound back up partway.

Thanks.

When re-installing it, is there anything special that needs to be done? I assume it can be lifted back into position like a normal driveshaft?

I should have the transmission installed before that so will use the floor jack to move it into position if needed.

Got the flywheel cover off finally. Will be using bolts instead of screws going back in. Had to use channel locks to get half of them out. Especially the two above the cross member.

Oil seems to be external only. Flywheel and pressure plate look dry. And rusty.

Next is the U-bolt cover. Then a break I think.

Got the bell cover moved back so have access to the ball joint now.

Added picture of the inside of the flywheel cover also.

Side note. The tranny fluid was still milky even after putting in fresh. When I get the tranny out I’ll try to rinse it out. I plan on using turpentine. Anyone done it with something else and get good results.

Once you get everything reassembled, fill the trans with Diesel fuel and idle the engine with the transmission in neutral for a while. The spinning cluster gear will splash the fuel around inside the trans case like the agitator in a washing machine. Drain the trans and let it drip dry overnight, then refill with 90 weight straight mineral oil, not hypoid rear end lube or some kind of synthetic "mouse milk". Stovebolt transmission gears are heavy, and super slick synthetic gear lubes don't let the synchronizers work right- - - -you'll grind gears, especially on a downshift.
Jerry

What kind of mineral oil Jerry. Never used it before.

Here it is Doug.

https://www.tractorsupply.com/tsc/product/traveller-ford-tractor-hydraulic-oil-2-gal-t806600

The transmission only holds a quart so you don't really need to buy a $40 jug.

Thanks Otto.

Oh. My trans holds 2 1/2 guards btw.

Now how do I get the u-joint apart besides removing the four bolts. Lol

Doug

Use a pry bar. The rear half of the joint slides back on the splined driveshaft. That's when the torque tube will slam down if it's not supported properly.
Jerry

You mean the part still attached to the trans will move forward or the part on the torque tube will move back...
Doug

What transmission do you have? Mine is the 3 speed and I swear it only took 1 quart after it was fully drained.

I have a 4 speed.. forget the number on it

This. It slides on the splines.

Ok. Got the ujoint separated and on a jack stand. I hate to admit it but I’m not as strong as I used to be. Maybe getting to 74 slowed me down some. Anyway I can lift the tube but that’s as far as it goes.
Can I jack the tube straight up to the floor and put both jack stands on it. Not sure of what the limits are on moving it are.

Doug

Jack the torque tube up against the floor and wedge a piece of 2 X 4 into the frame channel, with a C clamp or two to keep it from slipping. Then you can remove the floor jack.
Jerry

awwww, such fond memories. I totally forgot about the 2x4 trick. One of the many great suggestions I got from here, back when I was so busy under my truck.

Your SM-420 holds 6 pints (3 quarts) of 90wt Mineral Oil...

Mike B

Sounds like a plan.
Thanks for all the good advice

Doug

Ok. Got the tube up but the transmission still won’t clear it. Tried to move it to the side with no luck.

Doug

If I remember correctly, the rear tires needed to be hanging off the ground and the torque tube jacked into the floor before I was able to get the clearance to remove rear yoke. Once that is removed you should be able the slide the tranny back enough to remove it.

I’ve got it jacked to the floor. Did you have a 3 speed or 4 speed?

If you jack the frame up (or take the rear wheels off) and let the springs extend down that effectively shortens the torque (or at least moves it farther to the rear.) It's basic trigonometry. In a triangle with the hypotenuse (the torque tube) held constant length, and you lengthen one of the sides (the distance from the frame to the axle), then the other side HAS to shorten (move the end of the torque tube to the rear.)

I was never good at geometry. 😁 but I think I understand what you’re saying.
So I’ve got it up to the floor now and have a 2x4 wedged across to the frame. Both sides have c-clamps to hold in place. Can I leave that as I and jack up the rear and put it on jack stands. And do I put the stands on the axle tube or the frame?

But can I lower the tube to the ground instead then move it to the side?

Doug

You can't put the stands on the axle tube. What you need to do is let the springs relax (drop the axle in relation to the frame.) You might want to move the torque tube down a bit while doing that.

It's not possible to move the torque tube sideways unless you unbolt the axle from the springs, which is an option (but not a good one IMO.)

Here's another option. Does your truck have a crossmember (see attached pic) and transmission mount at the rear of the transmission? If so, that should be removable (5 bolts on each frame side rail). Once unbolted, it can be slid back and removed, then the torque tube can be dropped below the transmission, allowing you to remove it.

[On edit] from the last pic you posted, I see that you don't have a crossmember at the rear of the transmission, so you should be able to drop the torque tube below the tranny. You can then pull the yoke off the driveshaft, giving you more room.

How does the yoke come out. Just pulling on it. I had to use a crowbar to get separation on the joint to raise the tube.

Doug

Doug,

Yes, the rear half of the yoke should slide off (forward) of the splined shaft. It may be a bit hard pressed back onto the splines after your disassembly process, so may take a bit of persuasion.

You do have to make sure there is enough clearance between the torque tube ball/shaft/u-joint and rear of the transmission housing to allow the yoke to move forward off the shaft.

You could lower the front of the torque tube with a jack to allow clearance of the transmission housing to remove the yoke and then raise it back into place while you do what needs doing on the u-joint assembly.

Dan

Yup! Just make sure you take all safety steps while doing this. Keep that torque tube well supported during your presence under the truck.