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Lifted KJ's and CV Boot Damage
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=3&t=19499		 Page 1 of 1
Author:  Kugellager [ Mon Apr 09, 2007 11:45 pm ]
Post subject:  Lifted KJ's and CV Boot Damage
A week ago I noticed green goo on the front suspension on the passenger side of my Lifted Liberty. I soon discovered that the inboard CV boot had split on one of the middle folds neard the outer edge. Upon closer inspection I saw that it had appeared to split at a 'seam' near the edge of one the fold. I then noticed that several other folds had similar looking 'seams' that were, upon closer inspection, actually a groove near the edge of the boot folds. I lifted the passenger tire off the ground and spun the wheel so that I could watch the CV boot as it turned. I quickly noticed that these grooves are at the exact point where one of the edges of a neighboring fold touches the groove at the bottom of the rotation of the boot where it compresses.

Basically what you have on a lifted Liberty is that the CV angles are much steeper that the stock angle. This steeper angle causes the boot to compress together at the bottom of the boot. Since the entire boot rotates with the CV axel, the squished area and rubbing of the adjacent folds in the boot rotate as well. This is what causes the grooves around the edges of the folds and the subsequent failure of the boot.

I would strongly suggest that EVERYONE with a lifted Liberty regularly check their CV boots for this wearing condition.

If you see grooves, as you will in the following photos of my stock boot, that you are getting wear as I did and it will be only a matter of time before your boot fails. My boot failed after about 5k miles with the lift. I'm sure the other inboard boot is about to go too. The outboard CV boots don't look as bad on my Jeep.

I used a split boot for a replacement (Empi Part #86-2858-C) but this is only a temporary fix until I (or someone) can find a replacement boot that does not rub against itself due to the steeper CV angles. I may try moving the smaller side(cuff) of the boot out a little further along the CV axle shaft to slightly increase the spacing of the folds on the boot to see if this remedies the rubbing situation.

The Photos are as follows. Click the thumbnails

Boot showing several folds with wear grooves. Arrow is pointing to one groove. Also notice that the upper two folds on the upper right of the photo have no groves...They don't touch when boot is compressed at the bottom of the rotation :wink:
Image

Close-up of grove.
Image

Image showing how compression of folds cause groove to wear in boot. Note how the adjacent fold fits nicely in groove.
Image

Image showing split in boot at deepest point of groove.
Image

Cut away showing how thickness of boot as been greatly reduced at the groove due to the rubbing of the adjacent fold in the CV boot.
Image

Maybe this is sticky material...maybe for the tech section??? ...not sure.

John
];')
Author:  JJsTJ [ Tue Apr 10, 2007 7:48 am ]
Post subject: 
How many miles total are on those boots? I have two KJ's that have spent their whole lives lifted and (knock on wood) I have not seen any CV boot problems.

FWIW, I do inspect them before and after wheeling trips and I do make sure they get sprayed off to keep dirt from sticking between those ridges and causing wear. I also hit them w/ silicone spray every so often, I figure that helps to keep them from wearing. :?
Author:  Eddo [ Tue Apr 10, 2007 8:44 am ]
Post subject: 
Interesting I have probably almost 30k of lifted mileage and my boots look fine. I don't have any of those wear grooves.

Yes if you pull the boot up on the axle to stretch it out more it will help eliminate some of the compression and binding of the boot.
Author:  Kugellager [ Tue Apr 10, 2007 9:21 am ]
Post subject: 
JJsKJ wrote:
How many miles total are on those boots? I have two KJ's that have spent their whole lives lifted and (knock on wood) I have not seen any CV boot problems.
About 8700 miles on my 2005. I put my lift on at about 2500-3000 miles.

Hmm I like the idea of spraying them with silicone. I have thought of rubbing them down with graphite as there would be no liquid for anything to stick to.

I would suspect that the wear would vary from Jeep to Jeep. But that is how long it took with mine.

John
];')
Author:  Jeger [ Tue Apr 10, 2007 9:43 am ]
Post subject: 
Kugellager wrote:
JJsKJ wrote:
How many miles total are on those boots? I have two KJ's that have spent their whole lives lifted and (knock on wood) I have not seen any CV boot problems.
About 8700 miles on my 2005. I put my lift on at about 2500-3000 miles.

Hmm I like the idea of spraying them with silicone. I have thought of rubbing them down with graphite ans there would be no liquid for anything to stick to.

I would suspect that the wear would vary from Jeep to Jeep. But that is how long it took with mine.

John
];')


Thats a good thought with the graphite, has anyone tried that yet?
Author:  jereosbou [ Tue Apr 10, 2007 10:08 am ]
Post subject: 
ive got close to 60,000 miles lifted and havent had this issue i would do as you said and try stretching them all out. also measure your jeep to find out how much lift you have exactly maybe youve gotten more then usual somehow and it has caused this.
measure the height at you front skid plate and let us know what it is. id hate for it to trun out that your running more then about 3 inches as you will find replaceing the cvs themselves is a lot more pricey. fwiw i believe that about 11 inches under you front skid is max before you will start to have problems. anyway just a thought
Author:  Kugellager [ Tue Apr 10, 2007 10:11 am ]
Post subject: 
jereosbou wrote:
measure the height at you front skid plate and let us know what it is. id hate for it to trun out that your running more then about 3 inches as you will find replaceing the cvs themselves is a lot more pricey. fwiw i believe that about 11 inches under you front skid is max before you will start to have problems. anyway just a thought
It was about 10.5 inches under the front skid when the lift was new. Should have settled a bit since then.

John
];')
Author:  Jeepjeepster [ Tue Apr 10, 2007 10:22 am ]
Post subject:  Re: Lifted KJ's and CV Boot Damage
I always keep some silicone on all of the boots and bushings under the Jeep. I usually spray them at every oil change or after offroading.

I noticed you also had the Franken lift.. This probably wouldnt happen with the rustys lift for those that are worried and have that lift.

I have 9.5in on the lowest point of the front skid plate with 245/70/16 tires. :)
Author:  jereosbou [ Tue Apr 10, 2007 10:22 am ]
Post subject: 
you should be good to go with the actuall cvs then as i was at 11 till i put built my bumper now i back down to about 10 and 1/4 so im not sure i think you may just have bad luck.... let us know how graphite works for you adn if the problem comes back up.
Author:  DaveKJ02 [ Tue Apr 10, 2007 11:27 am ]
Post subject: 
What about if you cut the halfshaft band, pull the boot end outward and reclamp it? It wont be so "squished" onto itself. That's what I was planning on doing but never did.
Author:  Kugellager [ Tue Apr 10, 2007 11:31 am ]
Post subject: 
DaveKJ02 wrote:
What about if you cut the halfshaft band, pull the boot end outward and reclamp it? It wont be so "squished" onto itself. That's what I was planning on doing but never did.
That's what I mentioned I will try in the paragraph where I put the part number for the split boot.

Definitely going to try that. The replacement split-boot is Neoprene and a lot more flexible than the stock boot. I will have to find a regular solid replacment boot made from the Neoprene for when I do my Ball Joint and A-arms and do a proper replacement then.

John
];')
Author:  Blue KJ in PA [ Tue Apr 10, 2007 11:37 am ]
Post subject: 
Not that I know anything more than anyone else...but I have always sprayed the boots on my vehicles with WD-40 from back in the days before I could drive and was doing routine work on my parents cars. He told me to do on his cars and I have continued to do so since then till now. Inly time I ever lost a boots was when some friends and I took our cars in a mudding grass field/paking lot and did some"wheeling"...mostly donuts and mud flinging...ahh the carfree days of youth... and the boot ripped when it was put in contact with a big stick flung along with mud.
Author:  gopherbeats [ Tue Apr 10, 2007 12:34 pm ]
Post subject: 
I like the picture of the x-section... very interesting
Author:  deboy922 [ Tue Apr 10, 2007 2:34 pm ]
Post subject: 
I have 25k on my boots, and I recently failed the passenger side inner cv boot. I did not inspect it close enough to notice any grooving. I will definitely check the driver's side tonight.

The dealer replaced the my torn boot, and the new boot looks much better in terms of a lot less binding. I am not sure if this was accomplished by sliding the boot up the smaller shaft.

I would really like to make my driver's side boot have less binding. But I do not yet have the confidence to cut the factory clamp, slide the boot down the small shaft, and re-clamp.
Author:  RespectMyLibertay [ Thu Apr 12, 2007 12:40 am ]
Post subject: 
I've posted a warning before on other topics, about a problem I faced. I took my KJ in for a t-case problem, and the mechanic, after putting my KJ on the big lift (swaybars still on), noticed my inner CV boots, on both sides, getting pushed inward by the bottom of the strut assemblies/clevis's which were fully drooped obviously. It may sound weird, but jack up your KJ on both sides and take a look at the clevis area. It should be relatively close to your inner CV boots, but contact is something you don't want :oops: It never did damaged my boots as far as I can tell, and I ended up getting Al's arms which fixed the problem; the area that contacted the boot moved out just enough to miss the boot now. I may have been the only one to have had this problem, but it was definitely odd and may be happening others without their knowledge. I have the first version of Frankenlift, but I'd suggest anyone with a lift double-check.
I'm not crazy (I should have taken pictures), but take a look and even if you don't see contact, you'll be able to see what I'm talking about since the strut assemblies drooped move down into that area.
Author:  Kugellager [ Thu Apr 12, 2007 9:46 am ]
Post subject: 
RespectMyLibertay wrote:
I'm not crazy (I should have taken pictures), but take a look and even if you don't see contact,
Riiiiight! :lol:

I would not be surprised that this happens at all. There are always going to be variations in suspension geometry from vehicle to vehicle. After a lift I would not be surprised in some cases that the clevis may hit the boot. In my case the rubber bumper on the lower puck seems to prevent the clevis from hitting the boot.

On that note. I have installed the Empi # 86-2858 split boot and moved the outer cuff out about an inch along the CV shaft. I am convinced that this will only be a very short term solution. The reasons for this are as follows: I jacked up the passenger side under the frame (side with new boot) and let the suspension fully flex. I then spun the wheel and watched what the boot did as it spun. The boot at full suspension flex still compresses quite a bit even though the small cuff is out further out than the stock mounting position. I noticed as I spun the wheel in this configuration that a gap occurred at the split in one spot. This did NOT occur when the boot and suspension is not flexed out with the jack under the lower a-arm. I will continue to watch for CV grease over the next couple of weeks. The correct part number for the non-split inner boot from Empi is 86-2340 and the outer boot is 86-2348.

Empi Jeep Liberty CV Boots

John
];')
Author:  Kugellager [ Sat Apr 14, 2007 9:27 am ]
Post subject: 
Well, less than a week into running the split boot and I am already noticing CV grease seeping out of the seams. It is not splattering out like it did when the stock boot split from the wear but it is seeping out along the seam and I have only put about 30 miles on it since install. Luckily I have a couple of solid replacement boots on my way too me.

The split boots IMO/IME(limited) should only be used as a very temporary bridge to replacement with a solid boot as Jeepin Al recommended.

John
];')
Author:  tjkj2002 [ Sat Apr 14, 2007 9:36 am ]
Post subject: 
Kugellager wrote:
Well, less than a week into running the split boot and I am already noticing CV grease seeping out of the seams. It is not splattering out like it did when the stock boot split from the wear but it is seeping out along the seam and I have only put about 30 miles on it since install. Luckily I have a couple of solid replacement boots on my way too me.

The split boots IMO/IME(limited) should only be used as a very temporary bridge to replacement with a solid boot as Jeepin Al recommended.

John
];')
Yes you are correct,split boots are a temp fix,just good enough to get you back home and put a reguler boot on.Changing the CV boots is really not that hard,just kinda messy with all that grease.Used to change CV boots alot in the military until we found out that it's easier just to keep new CV's on hand.Getting the CV out of the KJ is another fun task but again not hard with the correct tools.
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