What does a blown CV shaft look like???

NU ARTY BOY · **Posted:** Mon Oct 30, 2006 7:07 pm

Jeepin Al wrote:

A couple of things,

The bump stop is on the top, to put pressure on the entire structure. If the bump stop is on the bottom it it would rip out the lower ball joint right out of the spindle.

And yes the boot is ripped. If you can find the hole and its not tear you can fix it. I used brake cleaner to clean the boot, an file to rough up the area and silcon sealant. inject a little sealant in the hole to make a plug, put some on the outside smooth it over the hole with minimal pressure. Let the KJ sit for an entire 24 hours. Pop the lower band off the boot, slip a needle grease fitting between the axle and boot (make sure you don't put another hole in it and fill that bad boy fill of grease. If there is a tear, you are SOL, time to change the boot.

Next question, is did you forge any rivers or puddles, mud bog or anything else like that before you discovered the hole. If you did you will need to clean the CV joint out. So replace the boot at that time. Most likely the CV is not toast. Keep driving it and it will be.

As for the poor angles, it appears that the ball slots in the housing catch the axle shafts causing the binding. Jeff Daniels Jeep has cut the housing down or back and regrooved the retaining ring, eliminated the bind. Neat trick.

The JE Reel shafts are really HD, I have beat mine to death and they are still going strong with minimal snap crackle pop! In fact if you grease all your CV's the binding noise will all but be eliminated.

Hope this helps a little
Al

No, I haven't taken it off pavement since I installed the lift. I had a problem getting the UBJ to tighten down and didn't drive it until I got that taken care of.

Thanks for the advise Al. I'll see if I can repair the boot. But do you think the dealer will fix this for me if I am still under the warrantee?

KJ-BOL · **Posted:** Mon Oct 30, 2006 7:22 pm

NU ARTY BOY wrote:

But do you think the dealer will fix this for me if I am still under the warrantee?

Most likely not - you gotta try it hard - go to 2 or 3 dealers - I do know that BakerKJ got his replaced but i think he had to pay for it.... when you lift a KJ you changed the factory stuff on the suspension thus probably voiding your warranty on THE SUSPENSION only...

Jeepin Al · **Posted:** Mon Oct 30, 2006 8:42 pm

"are you talkin to me...are you TALKIN TO ME!... Yea I guess, Jeepjeepster,

The bump stop theorically (I wish inginears could spell) are placed in the position to supply a "soft" place for the suspension to hit and to limit its movement before a componet is damaged by a very forceful shock load (4500lbs of static load hitting a stationary object such as a a-arm) thus breaking the part. Something a kin to what happens to the KJ's stock upper ball joint everytime it its the spring.

Example: With my three inch lift, (way back when) I had the stock bump stop. One day I noticed oil on the axel shaft. I thought I tore a hole in my boot. On closer inspection, I put the strut rod of my fairly new Old Man Emu strut right thru the bottom of the strut. So the strut or shock acted like the bumpstop.

So if the ol' bump stop was placed on the lower arm, the force of the hit on the bump stop between the frame and arm would all be transfered to the lower ball joint, tearing it from the lower arm in tension. With the ol' bump stop being placed on the upper arm when it gets hit the the force is spread over two ball joints and the spindle in compression, much better for the ball joints (however repeated compression hits will make the ball joints fail) unlike the full tension load on a single lower ball joint that will tear apart the ball joint the compression load, is equal to the tension load is better handled by the two ball joints and spindle.

One step further, this is why are lower ball joints fail prematurely. The lift on our Libertys, with the stiffer springs, and struts act like the bump stop on the lower a-arm, albeit alot softer, but it still puts a extremely high load on the ball joint. Much more that its working capcity and eventually it fails. It would be much better if the springs and shocks were attached to the upper a-arm. I was looking into a air bag system that would attch to the upper arm, but I stopped when someone told me they would be unreliable off road.

Ok you can wake up now! and yes I have no life I lost it when I brought the Libby home.

Al

If that didn't bore the living pooh out of you, you must be an engineer!

Bakerkj · **Posted:** Mon Oct 30, 2006 11:20 pm

The dealer will not warranty the boot. They consider it a wear and tear item. It was very expensive to have the dealer replace it. I had a trip planned, so i payed up so I could leave town. When it happens again I will just replace it myself.

corwyyn · **Posted:** Tue Oct 31, 2006 3:41 am

Jeepjeepster wrote:

Why do you have a bumpstop for the upper balljoint?

Because it came that way when I bought it from Signcutter?

I know with the Daystar I shouldn't have any contact between the UBJ and spring at full droop, but since the bumpstop was on I decided to leave it (just that little bit of added peace of mind). I do hear something squeaking on that side when I go over bumps/ruts, so I need to pull the wheel tomorrow before work and see if I can isolate the cause. I *think* it is just a slightly loose strut bolt, but I'll know more in the morning.

EDIT: got the tire off and checked it out, looks like the dust boot for the strut is torn so maybe thats the source of the sound? Anyway Jeepjeepster, here's a photo of my suspension at full droop (connected):

As you can see I do get contact with the upper portion of the knuckle, so I guess its a good thing that bumpstop is there :wink:

What does a blown CV shaft look like???

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