Got a new WUMP-WUMP I can't figure out -UPDATE-

Landy · **Posted:** Thu Nov 26, 2009 12:22 am

A new "WUMPER" going on underneath, isn't that what we all need? Joy.

Please help me with your thought's if you can. 2006, manual, 2-1/2 lift (not spacer). New Toyo 16" 245's MT,s and I just did new ball joints and a front end alignment 1 week ago. 58,000 miles...

I have a marvelous new WUMP that came on right about late August when I did the last rotation on my old set of 245x16 MT's. I actually thought it was something to do with the knobby tire being cupped. It was only a mild bumpity-bump so I ignored it thinking it would go away when the tire did. Then a week ago I got the new set of tires and did the front end work. In 1 week's time it is now a major noise. Scary like it will strand you.

It is smooth until right at 40mph then a constant wump-wump-wump sets in. It seems to "hide" at 70mph. Slow down to 50mph and is whumps and slow to 35 or so and it'll growl a bit. Stop, and it goes away until 40mph again. Repeat.

I tried to push hard back and forth on both ends of the drive lines and the CV joints. Truly, nothing there seems to have any play? I see no evidence of anything rubbing weird or anything else? Glad I got the 8-80 on the drive train when I bought it.

Your thoughts welcome.

Thanks,

Landy

InCommando · **Posted:** Thu Nov 26, 2009 1:06 am

front drive shaft?

Landy · **Posted:** Thu Nov 26, 2009 1:15 am

Wondered the same thing. I pulled over beside the road twice coming home tonight and crawled under Libby with a flashlight. Both drivelines were 'firm' when I tried to move them. Since the exhaust was scream'n hot tonight, I'll go out in the morning (before overeating and watching football) while everything is stone cold and try to determine better if a front "U" joint could be gone.

Could the driveline get out of balance somehow? I don't remember running over any stumps lately or hammering the underneath.

This is now bad enough you can definately "feel it" when it's in it's WUMP'n.

kskj · **Posted:** Thu Nov 26, 2009 2:12 am

Rear boot on the front drive shaft. Look real close I bet its gone.

candpliberty · **Posted:** Thu Nov 26, 2009 2:27 am

Try rotating the tires front to back. If the noise moves or goes away it's a tire.

Landy · **Posted:** Thu Nov 26, 2009 3:23 am

Rear boot, front drive shaft. I don't remember seeing one when I was under there with a flashlight beside the road tonight.

I shall look in the morning.

JMSMN · **Posted:** Thu Nov 26, 2009 1:51 pm

I would say a cupped tire. I get a whump'whump when i rotate my tires on my magnum. Noise moves with tires, cupped. 22's are finickey.

Neatus · **Posted:** Thu Nov 26, 2009 3:50 pm

I had a front drive shaft go bad once and it felt firm when I would grab it but it was bad and made a noise at different speeds.

Landy · **Posted:** Thu Nov 26, 2009 10:59 pm

Thanks for the feedback everybody

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

I had a similar problem last year that didn't end up being any of the above ideas that normally solve it. On mine, the factory trash-lock had split apart and damaged the bearings in the rear differential. I had it rebuilt with a DTT.

ShafferNY · **Joined:** Wed Dec 26, 2007 3:51 pm **Posts:** 88

My bet is a tire.

Landy · **Posted:** Fri Dec 04, 2009 4:00 am

Figured out what the clunky-whump-whump is today.

I wish it had been as simple as a tire. The problem started right about the same time I rotated the used up Cepek M/T's. I think it was a coincidence. Libby has new Toyo M/T's now and the problem did not go away. No wheel was bent. Installed new ball joints, second time. Didn't fix it.

Put in all new U-Joints this week. Didn't fix it.

Took a ride with yet a different mechanic from the dealership and he did a quick side-to-side motion. One direction the clunky-whump got worse. So, we thought ahaaa, wheel bearing.

Nope. That didn't fix it either. $320.00 for the bearing and race. -Not under the 8/80. Merry Christmas to me.

The dealership tore the front end apart today and there it was; the stubby end on the CV joint shaft lost it's little holding clip thingy from the inside and the ends of the spines are now munched. Sorry, I do not remember the technical names for the parts.

The dealership is concerned about coverage under the 8/80 warranty for the drivetrain because Libby has a 2-1/2 lift. They don't think Chryselor will warranty this repair. Says he doesn't know why the clip would break if it wasn't for potential over travel due to the lift. Tomorrow morning I will of course go and argue about it. I did call and ask the dealership for approval before the lift was installed, I was told, "Go ahead." -No, I didn't get that in writing.

Anybody else ever heard of such a thing??? I am open for your thoughts, suggestions, ideas and comments. Sounds like potential bucks doesn't it.

Thanks,

Landy

QuestMan · **Posted:** Fri Dec 04, 2009 10:43 am

Try a different dealer. Different dealers will warrant different things. I've had one dealer say "NO!" to replacing a cv under warranty, due to the lift, while another one said, "Sure!" to the same issue. Some dealers are more lift-friendly than others.

Hood297 · **Posted:** Fri Dec 04, 2009 11:45 am

I had the exact same issue and was going to submit it, but i see you have already found it. I had to replace the Passenger diff stub shaft, passenger CV, and the little clip thing you speak of.

I'm afraid that your warranty battle may not end in your favor since not only will they throw anything they can, true or not at you to say your the reason it messed up. but a lift certainly could aggravate the c-clip as well as CV.

Landy · **Posted:** Fri Dec 04, 2009 3:43 pm

I wish I could get Libb to a different dealer, but the little guy is broke and torn apart.

On the diff stub shaft issue, if I am going to have to replace it (them) are there longer ones available to woek better with the lift kits that alot of us have?

I would naturally be concerned for all of us...mine is a Rocky Road Rockfather II 2.5" lift.

tommudd · **Posted:** Fri Dec 04, 2009 4:17 pm

you don't need or want longer ones
I had a similar noise about two months ago, it was the passenger side CV and intermediate shaft, all rusted etc. Intermediate shaft is dealer only item, ( thank goodness I bought a new one for 50 bucks from another member! :wink:

) outer CV cheap from NAPA 55/60 bucks get a reman'ed one
JeepinbyAl does have cut ones available but unless you go over 4 inches not needed. Mine lasted over 95,000 miles lifted over 3.5 inches

Landy · **Posted:** Fri Dec 04, 2009 4:35 pm

OK, thanks Jeepers. I called Rocky-Road and they were friendly, but of course said they'd never heard of such a thing. He thought the travel would be the same, with or without the 2.5" lift. That was his best argument.

So, if you were going down to your friendly dealership, what would your best argument be?

mochodurazo · **Posted:** Fri Dec 04, 2009 5:19 pm

ShafferNY wrote:

My bet is a tire.

x2

Landy · **Posted:** Fri Dec 04, 2009 11:53 pm

Clearly the issue was the stub shaft at the CV joint, broken inside and rattling.

The dealership reviewed the warranty again and decided to honor it. Wonderful. I told them clearly I had owned 3 Jeeps and my wife is on her 2nd so if they wanted me as a continued customer they should consider all the facts. One winning point on trying to blame it on the lift was from Mr. Mudd. 95K with a 1" taller lift and his didn't fall apart.

THANKS for the feedback!

kskj · **Posted:** Sat Dec 05, 2009 12:04 am

Nice to here that they are going to fix it under warranty.

Got a new WUMP-WUMP I can't figure out -UPDATE-

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