U-Joint Rear Drive Shaft

[PaulN]

So I may just be being dumb but you guys have always steered me right in the past. Have been having some bad vibrations and clanking when putting into reverse along with tranny fluid leaking from the transfer case so I thought I should check the U-Joints.
Have been away at college for awhile so haven't been driving it too much but when I went to check was noticing some slippage and rubbing and saw that the inner U-joint on the H yoke was missing the external retaining clip and pushed to one side and had been rubbing the yoke. Looked like I should just replace it so I marked and pulled the driveshaft today and loaned a press from a buddy. Hours later and still couldn't get any of the caps off that joint. Started to work on the outer joint that hooks up to the tranny thinking that I needed to take that off first to get the inner one out but that didn't really make much sense to me. Is that the case and if so do I need to replace the cv joint inside the H yoke? Everything is pretty seized up now and thinking I might have done some damage to the inner CV or ball joint...but I'm new to the drivetrain so might not be calling it the right name but the inner ball joint between the two U joints on the spicer style shaft.

Is it worth it to just take the driveshaft to a shop and have them press it out and replace the joint or should I just give it a little more. I've mostly just been worried about damaging the yoke or shaft but might just be being stupid. I was planning on just replacing the one U-joint because it is only about a 5 year old shaft.

Any advice would be appreciated.

 

[EPB72]

If the centering ball is rusted /siezed as well you might be better off just ordering a new shaft ,,if you have a drive shaft shop rebuild it you probably be close to the new shaft price.. but maybe someone could get I apart for closer inspection and plan on both joints and centering ball in the double cardan joint as a standard rebuild..

 

[unimogger]

The H yoke is commonly called a double cardan joint, and there are several videos on Youtube showing the order in which they are disassembled and reassembled. It really only works in the correct order, so check it out. They are not for the faint of heart, it needs a delicate touch to hold everything in place while pressing the caps in and not getting a needle loose in the cup. The centering ball is spring loaded, which doesn't help, just one more thing to wrestle with.
Good luck

 

[66BlueGoose]

Order does matter, going from memory, disassemble joint closest to the main shaft first (I don't remember which side of that joint to do first), then do the outer one. Reassemble in reverser order. Soak the heck out of it with PB Blaster or other favorite solution. Make sure to pull any grease fitting first, they will get in our way. A good puller with breaker bar and/or impact gun may be needed.

 

[PaulN]

Okay great thanks for the help. I was thinking it was a double cardan joint but wasn't 100% sure and saw a few videos but may have started before doing enough research. Helps a lot knowing to rebuild they should all be replaced. I was hoping that I could just replace the one U-joint but that makes sense since they all have such small tolerances and I was thinking how could I take the one U-joint out without the centering ball needing to be replaced also.

Do you think that the vibrations and tranny fluid leaking a little was coming from the U-joint rubbing and being off center? I also was having some slippage when I was turning so I was thinking it had to have just been from the angles off the off center U-joint?

 

[SteveL]

I just had my suburban checked out for vibration I thought 2as u-joints. U-joint was bad but also had a worn out yoke ont the rear end. Never hurts to have the driveline shop check things out. If yours has ben vibration for a while i might have wore out the seal in the output.

 

[Rustytruck]

If you have a good driveline shop take the shaft to them. by the time you buy all the parts your halfway to a new shaft. for about a 100 bucks in labor its done. 2 years ago my local drive line charged me about $150 to replace all u-joints and the centering ball assy check and balance the shaft. its a pain in the ass job. pull the shaft extend the shaft, clean the splines and check for looseness if loose dont waste your money and buy a new shaft. they are a bargain in comparison these days. they last 20 years with proper care so expense divided over time is nothing. a failed bad shaft can roll your rig and do great damage. not worth the risk on a rear shaft doing full time duty. replacing one joint is a trail fix or a fools repair. all the joints went into the shaft at the same time and did the same mileage so while a bad joint is a warning the others are on their way out. heed the warning the next time you may not get one. I have thrown a shaft under load its not a great experience and don't wish it on others.

 

[PaulN]

Alright thanks so much for the help guys I appreciate it. Ended up just taking it to the driveline shop and talking to them about it instead of messing anymore with it. Seems I'm gonna have to go for a full rebuild. I came back home to try and drive the bronco over to have them take a look at the differentials but couldnt get the 4wd to engage at all.

 

[DirtDonk]

Well better to find out in your driveway I suppose, than sometime out in the field when you truly need 4wd.
Now you've got two projects, but at least they're both leading to a more reliable drivetrain.

Some of these things need regular maintenance anyway. Whether you drive them or not sometimes!
A typical double-cardan type driveshaft with slip joint has five Zerk fittings to grease periodically. If you have non-greasable joints, you still have the female grease fitting in the double-cardan yoke and the joint in the slip shaft to take care of.
Not to mention wheel bearings and gear lubes to think of.

Good luck. Hope the rebuild fixes the issues, but likely at least not all of them.
A vibration could come from several issues. Leaking trans fluid from the transfer case is usually nothing to do with u-joints.
Doesn't hurt to make sure it's all new of course, but you probably have other issues still to deal with.

Clunking can be the driveshaft, transmission, transfer case or more likely the differential.
While the shaft is out, spin the rear pinion yoke by hand to see how much play there is in the differential.
Have you replaced the gear oil in the differentials ever? Wheel bearings? Transfer case fluid?

Sounds like you have an automatic. Is it a stock C4? If it's truly ATF coming out of the t-case and you did not fill the t-case with ATF, then it sounds like the seal between the rear of the auto trans and the t-case has failed.
But I've never had to deal with that one, so others will have more knowledge on whether that's the likely culprit or not.

Good luck!

Paul

 

[PaulN]

Paul thanks for the advice I seriously appreciate it a ton. Either way if it fixes them or not I'm glad I'm doing it because its helping my understanding so much more what I think I know which I dont typically! Definitely have some other issues as I have not been maintaining much while I was away at school. I do have an automatic and I believe it is a stock C4 but not 100% sure, 3 on the tree but my knowledge on it isn't the best.

 

[DirtDonk]

Happy to help. Good luck with it all. Lots can happen while you're at school, the beast part of which is getting edumacated so you can get a job to pay for the fun stuff with the Bronco!
Hopefully this "spare time" many of us have right now can get filled with some more learning. The fun stuff...

When using the phrase "three on the tree" that is only used for manual transmissions.
You do in fact have a three on the tree with an automatic that is a three-speed too of course, but nobody uses that phrase except to describe a manually column-shifted manual transmission.

The C4 is the stock Bronco automatic for '73 through '77. The '78 and '79 used the larger C6 with their larger engines, but all Early Broncos with autos were the C4 from the factory.

Paul