Bad axle u-joint?

Jeffncs

Jeffncs

Well-Known Member
Joined
Apr 4, 2017
Location
Wake Forest
Is this a bad axle u-joint? I installed new bearings and gears couple years back and all parameters were dialed in perfectly (pattern, backlash, pinion bearing preload)

Took it out in the snow and heard a rhythmic clunking. Only hear it when in 4H and 4L. Not present when hubs licked but in 2H

77 Bronco D44
Rebuilt driveshaft with new u-joints
Old axles u-joints (unknown age!)


 
Shake the axle shafts with your hands, see if there is play.
 
Jack each front wheel up off the ground and have someone else spin the tire back and forth while you look at the shaft, play would be visible there. Also push on the top and bottom of the tire to see if ball joints are good.

Id do the same for the driveshaft, and push up on the driveshaft really good to see if the pinion bearings are tight. If it’s new gears with a crappy crush sleeve or if you used the old crush sleeve it could be a loose pinion nut
 
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shawn said:
Shake the axle shafts with your hands, see if there is play.
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The diff is still assembled so it’s tough to tell for sure b/c I can only access the yokes to wiggle and shake… but if there’s any play, it’s fractional.

Here’s a pic of the oil - this was right after I parked running the 4wd so it’s still aerated and looks shiny. The shiny flakes are really just miniature bubbles.

IMG_0519.jpeg
 
Shreddinlettuce said:
Jack each front wheel up off the ground and have someone else spin the tire back and forth while you look at the shaft, play would be visible there. Also push on the top and bottom of the tire to see if ball joints are good.

Id do the same for the driveshaft, and push up on the driveshaft really good to see if the pinion bearings are tight. If it’s new gears with a crappy crush sleeve or if you used the old crush sleeve it could be a loose pinion nut
Click to expand...

I’m wrapping my day but did a quick test of the d/s. The pinion doesn’t budge but the slip joint in the middle of the d/s wobbles. It also has a lot of rotational play…. It’s worn out. The rear slip joint doesn’t wobble at all. Could that do it?
 
You don't even need to jack it up to check the axle joints. If the hubs are locked and the t case is in 2wd, there will be enough play in the drive line to see if there is movement between the yokes on the axle.


Jeffncs said:
The rear slip joint doesn’t wobble at all. C
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Was it in gear? In my experience the driveshaft slip joints always have a small amount of play, unless they're under load. If it's in gear, it won't be able to move so will feel tight.

Also, has this setup ever worked properly? Is the sound new? The only reason I ask is that there may be things like driveshaft angle that need to be checked if the lift height/caster/etc has changed.
 
shawn said:
You don't even need to jack it up to check the axle joints. If the hubs are locked and the t case is in 2wd, there will be enough play in the drive line to see if there is movement between the yokes on the axle.



Was it in gear? In my experience the driveshaft slip joints always have a small amount of play, unless they're under load. If it's in gear, it won't be able to move so will feel tight.

Also, has this setup ever worked properly? Is the sound new? The only reason I ask is that there may be things like driveshaft angle that need to be checked if the lift height/caster/etc has changed.
Click to expand...

Thanks - I’ll check the axle play with the hubs locked later tonight.

I’ll also check the front d/s for play with it in 4H. The rear d/s had zero wobble nor any rotational play. The front d/s (not in gear but holding each half) had obvious wobble and rotational play. The wobble was 1/8 - 1/4” displacement; rotational movement was probably 3/16” (the sections spun 3/16 or more when twisting each in opp directions).

This was a complete, ground up rebuild. The D44 center was rebuilt. Axles were installed as they were with used u-joints. I installed new u-joints in the d/s but didn’t touch the slip joint aside from shooting some grease into the zerk. Aside from running around town, the 4wd is largely untested until now. Wife just putts around town with it. I took it out into the snow.

I pulled a spare front d/s out of storage. It had some minor wobble and minimal rotational play. Wobble and rotation was … maybe 1/16” each.

I believe the d/s is shot. I’m planning to replace the axle u-joints and will check the ball joints TD which are also an unknown age. They were tight when I assembled and didn’t mess with them when rolling the axle assembly under the truck.
 
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Some more videos and results…

T-case in 4H and hubs locked - no obvious play in the axle u-joints.






T-case in 4H and hubs locked - tested play in the d/s with some reference points.



 

Attachments

  • IMG_0527.mov
    7.6 MB
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For comparison, this is the slate d/s in a vice. Almost no rotational play.





Also - driveshaft angle is 18°

IMG_0525.jpeg
 
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Jeffncs said:
Yes. All new parts except the actual steel housing.
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Well that rules that out. Honestly u-joints can click and pop without seeing discernible play. If they were ran dry (even if you have greased them up since ownership) the needles could have fractured or otherwise inside the cap and when force is applied they will talk to you all about it lol
 
skyhighZJ said:
Well that rules that out. Honestly u-joints can click and pop without seeing discernible play. If they were ran dry (even if you have greased them up since ownership) the needles could have fractured or otherwise inside the cap and when force is applied they will talk to you all about it lol
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I’m really thinking the clunking noise is the axle u-joints. They’re unknown age and I assumed my truck would be done to scratch the 4wd itch…I was wrong. I need to get hers working correctly b/c it’s the right thing to do but also b/c it’s bugging the heck out of me!!
 
Jeffncs said:
I’m really thinking the clunking noise is the axle u-joints. They’re unknown age and I assumed my truck would be done to scratch the 4wd itch…I was wrong. I need to get hers working correctly b/c it’s the right thing to do but also b/c it’s bugging the heck out of me!!
Click to expand...
I think a fresh set of spicers would solve you’re issue and even if not it’s a good bit of assurance that they are new and won’t bind or bust causing more issue in the gorgeous EB of your wife’s.
 
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