U-Joint Q...

[DIGITRUCK]

Hey,


'88 XJ Cherokee Laredo 4.0L Auto.


I had the U-Joints changed (with better ones that have the nipple for lubing) on the rear driveshaft (both ends) and one U-Joint on the front (I think, can't remember exactly where).

The Mechs that did the work said I don't need the Two U-Joints changed on the Front driveshaft (the one with the double-yoke) since those hardly ever break.

My Jeep is almost 18 yrs old (I had her since '96) I've been changing virtually everything whether or not it was bad so I won't have to encounter any surprises later.

1. Are these Mechs correct in that those U-Joints on the Front driveshaft seldom go bad?

2. Also, should I have the U-Joints on the Front Axles changed too or don't worry about them?

Thx, Phil

 

[XgeekstarX]

sounds to me like the mechanics didn't know how to rebuild a double cardan and just said they didn't need to be replaced.

 

[Mikel]

In a part-time 4x4, the front driveshaft either spins with no load (if there are no locking hubs), or doesn´t spin at all, if the hubs are unlocked. In either case, I would expect those U-joints to wear much slower than the rear driveshaft´s.

 

[Matthew Currie]

I would say your mechanics are probably being honest. Those joints can last a very long time, and if they aren't worn out yet they simply aren't worn out yet and don't need to be replaced.

 

[DIGITRUCK]

Hey,


How can I tell if the U-Joints are wornout? Do they make a certain type of noise?


Also, should I have the U-Joints on the Front Axles changed too or don't worry about them? And, how would I know if they're wornout?


Thx, Phil

 

[Ray H]

The front driveshaft u-joints very seldom wear out from use because they usually arent under any power or strain and they dont go through the range of motion that the axle ujoints have to. What happens to them though is they dry out, and the factory ones arent greasable. When this happens theyll usually squeak.
The front axle ujoints will go through much more range of motion than any other ujoints. They will wear out as well as go dry and can bind and make a popping sound when you turn.
I like the ujoints with the grease fitting in the cap, its easier to get to and it doesnt weaken the cross of the joint. If you use ujoints with the fitting in the cross at least make sure they are installed so when they are under power, the grease fitting hole is under a compression load and not tension. the center section is stronger that way.

 

[Johnny V]

Hey,
The Mechs that did the work said I don't need the Two U-Joints changed on the Front driveshaft (the one with the double-yoke) since those hardly ever break.....1. Are these Mechs correct in that those U-Joints on the Front driveshaft seldom go bad?
Thx, Phil

I just replaced both front axle u-joints in my '89 Laredo with 193,000 miles.

Driver's side u-joint looked good as new and the passenger side was going a little dry on one arm. So I think you mechenic was being honest. I replaced the hubs and figured I'd do some preventive manitance and change the u-joints too as I don't want to have to pull the axles for a while.

 

[mattmankow]

Axle joints should definitely be looked at occassionally. They wear at a much greater rate.