AFAIK, all WJs use a CV on the front shaft. In reality, a double-carden IS a constant velocity joint, but using a CV on BOTH ends makes for a smoother power flow with less vibration. If they used a DC on both ends, the shaft would tend to vibrate a lot in the middle, right where the slip joint would be.

Remember, front wheel drive cars weren't popular in the US until the CV joint as used on the drive axles. U-joint drive axles tend to try to straighten out the steering when power is applied in a turn. You'd have to have driven an early European front drive car to know this.

I'm getting a little long winded, but the physics of a u-joint are interesting. With a single u-joint, the shaft velocity changes every 1/4 turn and the change is dependent on the angle of the drive, the more angle, the more velocity change. A double-carden cancels this out, but the centering ball takes a licking. A CV joint has an internal yoke with ***** that ride in grooves to do the velocity cancelling. The major problem with a CV joint is it doesn't have much of a provision for length change. There are internal splines, but they are short. To me, I think the best driveshaft would be one with CV joints on BOTH ends without internal splines attached to a shaft with long splines in the center. That way there would be smooth power flow with the length change needed for suspension movement. Now I'm trying to be a drivetrain engineer!

 

Last question. Do you know if all WJ's have cv joints on the axle shafts versus the u-joint type on the XJ's? If so, how to they hold up an a lifted vehicle with 33's? Is it better to swap the axle shafts over to the u-joint style?

I am just trying to get a cost idea of how much to change everything over. I like the way the WJ's look when lifted but there seems to be more modifications needed to make it work versus the XJ.

 

WJ axle are wider than a XJ axle. So not sure if u can change it out to u joint style

 

I was wondering if someone makes an aftermarket axel shaft with u-joint ends for the WJ. Seems like I saw it somewhere or someway you can modify?

And also how well does the cv joint on the axel shaft hold up on a lifted vehicle with larger tires? I would think larger tires would limit the life of a cv joint.

 

CV's do fine on my 5.2 ZJ. I did bust one but I think it was original with 160k on it. The whole axle assembly was ~$70 from autozone with lifetime warranty so if anything you could afford to buy a pair and keep stashed with saran wrap or whatever. So much smoother than the u-joint too. If you do find a cheap option to upgrade to the U-joints they can definitely be made stronger but IMHO CV's are good enough/cheap enough/easy enough to replace. I could probably do one on the trail in ~30 minutes if I wasn't poking around.

 

MY opinion is the CV joints actually should last longer because of the smoother power flow with less shock at the wheel. As stated,all axles will fail if pushed hard enough, but they are just as easy to change as u-joints. The only bad part might be the rubber boots could get punctured easier. I'd put my money on CVs. U-joints are easy to change on the trail if you need to and require less space to carry spares, BUT you can change a CV shaft quicker.

As I've said before, the real problem is the 3-link rear. It needs to be converted to 4-link if you want to get serious. The attachment point of the upper control arm is a ball joint on top of diff and is not very strong. The idea with this design was to eliminate the track bar.

 

Great thread on CV vs U-joint: http://www.jeepforum.com/forum/f9/wh...nt-one-854790/

Edit: Even has animations!

 

Ok yall, I didnt find anything in the search that seemed to fit my issue. Ever since i got my jeep (94 ZJ limited 4.0) I have had to constant problems. The alarm and a very loud knock. I believe the knock is coming from the top end but not sure with all the extra noise. It speeds up with the engine and does not get quieter as it warms up. I tried seafoam and some others with no luck. Just changed my oil and went with a heavy oil to see if that helped. It didnt. if anything it got worse. As for the alarm, I have tried almost everything and it still sometimes goes off. I have grounded every purple/yellow wire I can find and removed the small relay in the glovebox and it still went off when my battery died. I really dont want to take the dash apart for the vtss box. Any help is appreciated.

 

Thanks guys for the great information. I had a choice between that sweet looking 2002 GC or another 98' XJ. I ended up going with the XJ. A GC will be in my future though. I do want to build one eventually.

 

Replaced all the o-rings and replaced the one injector that was leaking, now I have two more leaking and still a rough idle. They are leaking from the eletrical connector. Any suggestions?

 

Leaking from the electrical connector? Definitely broken. Replace them

 

Yeah, leaking from the electrical connection is no good at all, definitely need to be replaced... just as a general thought, electric and gas is not a good mix at all but, I'm sure you know that.

 

It was suggested that i use new bolts when changing valve cover gasket. But i cant seem to find them online. Any idea where to get them? 93 zj 4.0

 

they may be talking about head bolts. You will be fine reusing valve cover bolts

 

Cylinder head bolts are under tremendous stress and should be replaced when you do a head gasket, but valve cover bolts only hold the gasket seal. no need to change them unless the hex heads are rounded.