The Stovebolt Site Forums The Shop Area Driveline Gaining access to driveshaft u-joint

I'm pretty sure that I have a u-joint rebuild in my future. The seals at the balljoint, and the seal at the rear have been leaking since I bought my 52 3100 six years or so ago. Just after I bought the truck, I changed fluids. Was shocked to find that my tranny was bone dry and no telling how long it had been that way. I've been filling it up regularly, and seem to be oiling the highway and my garage floor. I've had a hi-frequency vibration that becomes apparent about 35 mph and then seems to smooth out about 45. I'm thinking that vibration is caused by the u-joint which has been starved of lubrication for no-telling how many years. I have searched this forum, and read a lot about the fix. Pretty sure I can handle the mechanics of it. The problem is that I don't have a lift. I've had both my shoulders surgically repaired in the past decade. I cannot lay on my back and hold my arms up for any length of time without being very painful. So, here is my question: I see that there is an access cover in my floorboard that appears to give access to the transmission. It appears to me that with that cover removed, I would have access to the rear of the tranny, u-joint, balljoint, etc.. Yet, I don't see anyone in this forum talking about doing that. What am I missing? Does this sound like a logical, viable way to gain access for this repair? Or, is that cover a booger to remove? Thanks for any help and also any additional guidance for someone attempting this repair for the first time.

If the weight of the vehicle is on the springs, there will be a considerable amount of down pressure on the torque tube. You'll need to jack up the frame high enough to take the weight off the wheels and support the frame (not the rear axle) with jack stands before unbolting anything at the rear of the transmission. You might be able to do some of the preliminary work from inside the cab, but I'd strongly recommend recruiting some help before you get to the point of actually unbolting the torque tube and the U joint. A friend back in high school in the early 1960's got himself pinned under the torque tube when it slammed down during a transmission swap on a 47 Chevy car because he had the jack stands under the axle housing, not the frame. He got lucky, with only a few cuts and bruises.
Jerry

I don't think you can do the job from the top. I suggest also that you check your rearend fluid level. The seal behind the bushing in the tube could be bad and allowing fluid to run back into the rearend. If you get enough over full in the rearend it could get past the axle seals and into the brakeshoe area.

Yes, I've read that tube has pressure on it. Thanks for the tip.

I've checked and don't have any fluid getting past the axle seals. Not only that, but there is a big puddle directly under my transmission.

Could be as easy as just needing new gaskets for the universal ball and collar. I would have a u joint kit too, just in case you find your vibration in the in the form of a u-joint.
Remember there is a seal at the end of the ball collar, that is retained around the end of the torque tube, make sure you have that seal in place and there are the two flat washers -one either side of the cork seal, if not it will be a leaker. I have seen a few trucks with zero or just one flat washer in them before.

I'm in the middle of an engine/tranny swap on a 49 now and if theres one thing that I'd rate as the worst part of the job it's having to crawl under that 70 year old beast with all it's accumulated grit and grime to get at those bell housing and rear tranny mounts, plus cleaning the torque tube up enough inorder to slide the slip nut and ball collar back enough to get at the U joint clamp bolts. I studied trying to avoid crawling under but determined I didn't have long enough arms with additional pivot joints, LOL.

re. leaks, like sstock pointed out you may only need to replace the seals on the ball collar, unfortunately thats one of those gotta get under to do it jobs....

I've got tendonitis in both shoulders and some kind of arthritis in my thumbs.
So I know from whence your coming from in having to limit the amount of time one can utilize said appendages in certain endeavors.....

Good luck
Dave

Spend a few bucks at the local coin car wash, and use the "engine degrease" stuff to spray away most of the age-old gunk. Reaching under there with the car wash wand is a little tricky but any crud you can dislodge that way won't need to be scrubbed/scraped away by hand.
Jerry

The day I can no longer crawl under the green turd.........sigh!

I feel for those who can't do things due to bodily injuries or surgeries of the past. I'm just waiting for my day to come along.

To the OP, can you try laying down on your back and then rest for a few minutes before you take the next step? A baby step, then rest?

I will say that once you have gotten your hands dirty from dealing with the gearbox, driveline, brakes, etc, the next time will be a little easier.

Had the truck's bottom side steam cleaned days after I bought it.


Mr. Steamer