Stump1883

Okay here I go again asking what I think is stupid question but it has been bugging me for a little while now. What are the CV joints that get worn out after lifts, and what are their funtion. I know the boots get torn alot after lifts and I know their funtion is to keep stuff from damaging the joint, but I don't know what the joints are for.

My friend just got a new(to him) 92' Jeep Wrangler. I know I know, why didn't he get a yota, he simply couldn't afford one and for some odd reason likes Jeeps. Ah well go figure, you can't save um all. . To make a long story short, he has a torn CV boot on the drivers side and I was trying to get him to hit some trils with e the other night but he was reluctant about it b/c the guy he bought it from told him about the torn boot, and he was wondering what the joint did in the first place, so I knew someone here would know.

Would it be an okay quick fix to Duct Tape the boot rip up and then hit the muddy trails, we ae trying to get into somethings right after it just rained the other night. Thanks guys, hope EVERYONE had a Merry Chirstmas.

metal22lica

i think CV stands for constant velocity. once the CV boot blows..most places wont just change the boot..they will only replace the whole axle because dirty and all that other good stuff gets up in there. hmm..i thought that SFA vehicles didnt have CV boots... here is a cool link i found LINK im not sure about taping it but i guess since you are probably going to have the replace the axle taping it wont hurt..just make sure you dont tape it so tight that the boot cant turn and stretch. if it does hurt it..no worries..its only a jeep...

Jay

Metal22lica is correct, it stands for constant velocity.

Lifting the vehicle will change the angle of the front driveshafts, causing the flexable ribs in the boot to rub themselves. Its this friction that causes the boot to wear and ultimatly tear. Replacement of the boot would be required if caught soon enough. However with extended driving on a torn boot, will cause the grease to fling out and accelerate the wear on the joint the boot use to protect.

No, Duct tape does nothing for you here.

Jay

supascout

On an IFS car, moast half ashfts ahve 2 CV joints, one at each end of the shaft. The purpose is to allow the half-shaft (axle) to effectivly bend so that when the suspention moves the shafts can still apply power to the wheel. They are simelar in function the the universal (u) joints on a drive shaft however there is a sliding function that allows the CV to apply power at greater deflection angles. Due to this sliding factior the CV wll wear out verry quickly if it is not kept steril!!! This is why the boot is so important.

That sead I believe that the Jeep with its solid front axle has U joints which are sealed by small rubber gaskets and not large boots. Verry verry rairly will the gaskets on a u joint go bad. Your friend needs to learn his truck better so that he can go and play more!

_traivs

jx94148

This is all correct except the tape part. Tape will help keep dirt out of a torn joint temporarily just like a band-aid keeps dirt out of your torn skin temporarily. If it tears you need to replace it ASAP. Too bad trucks don't grow new boots the way your body grows new skin. That would rock!!

Seriously... A Constant Velocity joint allows torque (twisting force) to turn a slight corner. On an IFS front axle the torque has to turn 2 corners. One for both steering and suspension changes (outer joint by the wheel) and the other for suspension and slight shaft legnth changes caused by suspension flex (inner joints closer to the engine).

That's about as simply as I can explain it. I hope I didn't make any spelling or grammatical errors.

Anyone else want to take a shot at this question?

Jay

Driveline 101

Jay

khaug

What a great site! IMHO, this oughta be required reading (with a test to follow!) for anyone thinking of lifting or lowering their vehicle.

Years ago, I owned a Porsche 944 Turbo S, which I'd lowered and which ate a set of CV joints every 5-6 track events. I finally figured out that lowering it had forced the CV joints to work at angles they never were designed to handle. I un-lowered it and the trouble disappeared.

Thanks, Jay. Have great holidays.

jx94148

Oh yeah, the driveshaft owners manual... .

That might be over some people's heads.

What's a shim?? :confused:

Stump1883

Well dang, I don't know how long the boot has been torn, he just picked up the Jeep from the guy a ew days ago. The guy had told him before he bought it that the boot was torn. But my friend not knowing a dang thing about Jeeps or anything 4WD for that matter had no idea how serious it was. I knew it was serious, not as serious as you guys have just now informed me of, but I knew it was.

My friends reley on me o help him understand his cars(Ford Escape, LOL ), and now his Jeep. He really needs to learn some of this on his own, but this whole post here would go way over his head, so I kinda help him break things down.

He is part of a Jeep Forum, but the people there don't help half as much as you all do. They would consider what I just asked a stupid question and not answer it for him, so I reley on you guys. Jeep people just aren't as friendly as us yota boys are I guess, go figure, they must just be mad over having a Jeep, must bea hard thing to live wth .

Thanks again guys.

jx94148

As far as I know the only Jeep with CV joints and rubber boots is the Liberty since it has independant front suspension.

All other Jeeps have straight front axles with Universal joints, no rubber boots. The joint is exposed and visible.

Stump1883

Yeah I noticed that today, this was the first time that I crawled under my friends Jeep since he got it a few days ago. I realized then that he didn't have any CV boots,or joints. But yeah, long story short we wen wheel'n and shorted out the alternator on his Jeep, LOL . I'm sad that his rig is out of comission for awhile but it just shows what Jeeps are really made of, funny mine has never flooded..... TOYOTA 4EVER(literally)