U-Joint Caps Keep Falling Off

Ourlife Whirlwind

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I just replaced the front axle u-joints and axle stubs. The u-joint caps keep falling off while driving. I know the c-clips are seated all the way. I just don't know why they keep coming off. Any advice would be appreciated. I am getting tired and annoyed tearing the front end apart.

It's a MOOG 371 U-Joint and Spicer 43205 Axle Shaft. I had to install the ABS tone ring myself so I hope the yoke did not get warped while pounding on the tone ring with the mallet. I put the yoke on a block of wood so not to damage it but it might have.

Also why do you think it is leaked gear oil? Would the loose axle when the cap came off damage the axle seal in the diff?
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Sounds like the 'ears' on the axle shaft that hold the bearing caps are stretched. The bearing cap diameter of that Moog 371 is the same as the preferred Spicer 5-760x so it has to be the driveshaft ears were stretched either during installation or while driving offroad. It happens. And make sure not to lubricate the ears/bearing caps when inserting them. That can make it easier for them to pull free.
 
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Sounds like the 'ears' on the axle shaft that hold the bearing caps are stretched. The bearing cap diameter of that Moog 371 is the same as the preferred Spicer 5-760x so it has to be the driveshaft ears were stretched either during installation or while driving offroad. It happens. And make sure not to lubricate the ears/bearing caps when inserting them. That can make it easier for them to pull free.

Thanks Jerry. I am ordering new Spicer axle shafts, Spicer 5-760x u-joints this time and Spicer ABS tone rings again now. I'll take them somewhere to be pressed on rather than pounding them on. That's the only thing I can think that is causing this issue.
 
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I had to install the ABS tone ring myself so I hope the yoke did not get warped while pounding on the tone ring with the mallet.
Next time you need to install the tone ring onto a axle shaft; place the axle in the freezer and the tone ring in the sun for a couple hours; the ring will just about slide onto the shaft instead of pounding it on with a mallet.
 
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Next time you need to install the tone ring onto a axle shaft; place the tone ring in the freezer for a couple hours and then the ring will just about slide onto the shaft instead of pounding it on with a mallet.

That is a good idea, but do you mean put the axle shaft in the freezer to shrink it so the ring slides on easier?
 
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I just replaced the front axle u-joints and axle stubs. The u-joint caps keep falling off while driving. I know the c-clips are seated all the way. I just don't know why they keep coming off. Any advice would be appreciated. I am getting tired and annoyed tearing the front end apart.

It's a MOOG 371 U-Joint and Spicer 43205 Axle Shaft. I had to install the ABS tone ring myself so I hope the yoke did not get warped while pounding on the tone ring with the mallet. I put the yoke on a block of wood so not to damage it but it might have.

Also why do you think it is leaked gear oil? Would the loose axle when the cap came off damage the axle seal in the diff?
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Unless your mallet was about 5 pounds of steel and you were all John Henry with it, it is unlikely you damaged the yokes. You do have an issue with the interference fit though. The snap rings are used for a far different reason than most understand. They are there mostly to center the joint so the two yokes don't wobble when they are spinning. They are not there to retain the caps.

A buddy visited the other day and when he was about to leave, I noticed one of his axle shafts looked just like your pic and told him we needed to fix that before he drove it home. We needed to order in parts so he left it with us. Upon disassembly, we discovered that none of his u-joint caps had the snap rings installed. Called him up to see who did the install (hoping it was him so I could give him large amounts of ribbing for being a goober) and he relates that he had them installed by a popular local shop about 5 years ago after he broke the stockers. You do any wheeling since then? Yep, been all over, Rubicon, Big Bear, etc. several times.
 
Thanks Jerry. I am ordering new Spicer axle shafts, Spicer 5-760x u-joints this time and Spicer ABS tone rings again now. I'll take them somewhere to be pressed on rather than pounding them on. That's the only thing I can think that is causing this issue.

Honestly just order revolution discovery 4340 chromolys. The price difference isn’t much difference from a new stock shaft and it’s significantly stronger.
 
Unless your mallet was about 5 pounds of steel and you were all John Henry with it, it is unlikely you damaged the yokes. You do have an issue with the interference fit though. The snap rings are used for a far different reason than most understand. They are there mostly to center the joint so the two yokes don't wobble when they are spinning. They are not there to retain the caps.

A buddy visited the other day and when he was about to leave, I noticed one of his axle shafts looked just like your pic and told him we needed to fix that before he drove it home. We needed to order in parts so he left it with us. Upon disassembly, we discovered that none of his u-joint caps had the snap rings installed. Called him up to see who did the install (hoping it was him so I could give him large amounts of ribbing for being a goober) and he relates that he had them installed by a popular local shop about 5 years ago after he broke the stockers. You do any wheeling since then? Yep, been all over, Rubicon, Big Bear, etc. several times.
Mr. Blaine I think I must have hulked the caps onto the u-joint and bent the ear. I used a hard rubber mallet to install the caps but sure bent the ear on the yoke. I'm not sure how the heck I did that. I tried to be gentle enough and only use enough force to get the caps seated on the u-joint. I have a pic of the new axle shaft uploaded also for comparison.

I am in the process of freezing the new axle shaft and laying the tone ring in the sun for a while to make that easier to install. Hopefully the new Spicer u-joints will be better than the MOOGs.


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Mr. Blaine I think I must have hulked the caps onto the u-joint and bent the ear. I used a hard rubber mallet to install the caps but sure bent the ear on the yoke. I'm not sure how the heck I did that. I tried to be gentle enough and only use enough force to get the caps seated on the u-joint. I have a pic of the new axle shaft uploaded also for comparison.

I am in the process of freezing the new axle shaft and laying the tone ring in the sun for a while to make that easier to install. Hopefully the new Spicer u-joints will be better than the MOOGs.


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That could have happened when the cap came out going down the road