How To Replace U Joints With Plastic Pins

[roymag118]

2004 Silverado 2WD Extended Cab 4.3L: Rearmost U-joint needs replacing. It has the plastic retainer pins that need to be heated/softened/melted. Question is: how will the replacement u-joint be retained? After it's apart will I find the usual external grooves for circlips, or will I find internal grooves? I'm hesitant about tearing this apart and then discovering that I can't get it back together again. I have done "traditional" u-joints before.

[2COR517]

I think the new u-joints will have grooves in the bearing caps, and you use a c-clip on the inside of the yoke. That's how the last set went in the Tahoe.

 

BTW, I have the best luck with the Autozone Lifetime NON greaseable u-joints. Any u-joint with a grease fitting has never lasted a year for me.

[Jsdirt]

Yes, the new ones will have clips.

 

Pay close attention to how far you press in the new ones -- if you go too far, the clips won't fit & you'll be doing it twice. Just watch the grooves as you press them in. If you press one too far, the cross will shove the other side inward. Don't ask how I know this....

[roymag118]

2004 Silverado 2WD Extended Cab 4.3L: Rearmost U-joint needs replacing. It has the plastic retainer pins that need to be heated/softened/melted. Question is: how will the replacement u-joint be retained? After it's apart will I find the usual external grooves for circlips, or will I find internal grooves? I'm hesitant about tearing this apart and then discovering that I can't get it back together again. I have done "traditional" u-joints before.

 

Attempted this repair today. I was unable to remove the old u joint. Heated the area with a MAPP gas torch, tried to push the joint apart using two sockets and a large old machinists vise. Broke the vise. Tried banging it apart with a socket and a three pound hammer. Nothing. Finally gave up. It's going off to a shop to be professionally done. I don't see how a backyard mechanic can ever get this style of u joint apart. This truck has about 90k miles of New England roads on it along with the related salty corrosion. Looks to me like you need a heavy duty press to get these apart, not a bench vise.

[txab]

2004 Silverado 2WD Extended Cab 4.3L: Rearmost U-joint needs replacing. It has the plastic retainer pins that need to be heated/softened/melted. Question is: how will the replacement u-joint be retained? After it's apart will I find the usual external grooves for circlips, or will I find internal grooves? I'm hesitant about tearing this apart and then discovering that I can't get it back together again. I have done "traditional" u-joints before.

 

Attempted this repair today. I was unable to remove the old u joint. Heated the area with a MAPP gas torch, tried to push the joint apart using two sockets and a large old machinists vise. Broke the vise. Tried banging it apart with a socket and a three pound hammer. Nothing. Finally gave up. It's going off to a shop to be professionally done. I don't see how a backyard mechanic can ever get this style of u joint apart. This truck has about 90k miles of New England roads on it along with the related salty corrosion. Looks to me like you need a heavy duty press to get these apart, not a bench vise.

 

Yes you need a large press to break the plastic rings. I wouldn't suggest the heating method on the chance that it might affect the yoke ears and make it where they would bend out of alignment. I've seen it before.

[roymag118]

Why in the world would GM use a U-joint design that's almost impossible to get apart? What's wrong with the external c-clips? I just don't get it!

[2COR517]

Why in the world would GM use a U-joint design that's almost impossible to get apart? What's wrong with the external c-clips? I just don't get it!

 

Cost savings on the assembly line.

 

You should make sure the u-joints haven't been replaced already. When we did the Tahoe, we used a portable ball joint press and big impact gun. Wouldn't move. I think we actually broke one of the c-clips. Pretty easy after we took them out.

[HawkScot]

Some of us backyard mechanics have 30 ton presses to do u joints and axle bearings. Those plastic pins go bang when they break. Only takes a few minutes with a press. Perhaps someone you know has a press?

 

Good luck!

[Mr. Smith]

2004 Silverado 2WD Extended Cab 4.3L: Rearmost U-joint needs replacing. It has the plastic retainer pins that need to be heated/softened/melted. Question is: how will the replacement u-joint be retained? After it's apart will I find the usual external grooves for circlips, or will I find internal grooves? I'm hesitant about tearing this apart and then discovering that I can't get it back together again. I have done "traditional" u-joints before.

 

Attempted this repair today. I was unable to remove the old u joint. Heated the area with a MAPP gas torch, tried to push the joint apart using two sockets and a large old machinists vise. Broke the vise. Tried banging it apart with a socket and a three pound hammer. Nothing. Finally gave up. It's going off to a shop to be professionally done. I don't see how a backyard mechanic can ever get this style of u joint apart. This truck has about 90k miles of New England roads on it along with the related salty corrosion. Looks to me like you need a heavy duty press to get these apart, not a bench vise.

 

 

 

Mapp gass won't get it hot enough. A good oxygen/acetylene will get it hot enough and the nylon injected crap will spiral out like a snake.

[Wingnut]

I did it with a butane torch...basically a small torch that attaches to those little green camping tanks. Or is it propane...Whatever.

 

You just have to keep heating them, they'll squirm out of the holes...LOTS more than you think there is in there. It'll usually "POP" when you're about done.

[winkman]

I used to heat them up with a torch until the Stuff would start flowing out, but Make sure to Aim the cap your heating Away from you because they have shot across the road on me more then a few times. We used to see how far they would Shoot. Ware safety glasses . Sometimes they Pop like a M80 too . Be Prepared

[rattrod30]

Years ago I had an 87 suburban. Pulled boat behind camper with it. Joint failed in Black River Falls Wisconsin. Heated joint with coleman stove to melt plastic. Still seems to have been the best method as one has a large amount of modest fire rather than a small very hot flame. Often tempted to bust out the camp stove when replaceing joints.