Odd noise/vibration

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

I'm a week out after my lift. Before my lift I noticed a slight noise that I thought was related to my having changed tires back in December. Now it's more pronounced since the lift and seems to happen pretty regularly at 1300-1400 RPM's when under load anyway (accelerating) and possible worse going up hills.

When I had the rear shock noise problem we got under the car and shook things and nothing seems to have any slop in it (shocks, sway bars, drive shaft).

Any thoughts?

tommudd · **Posted:** Wed Apr 27, 2011 10:30 am

check rear boot on the front driveshaft
check rear u joints, driveshaft will not show they are loose as it seems ours just rust up and more or less get rusted solid. Drive for a few miles then put your hand close to the rear ujoint, most are hotter than **** if they are going or are bad
start there and then.............. :wink:

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Finally set aside some time to check out these things and neither of them seem to be the issue. The rear boot on the front drive shaft looks perfect. I drove about 4-5 miles and then checked for heat coming off the U joint and the only heat I felt was coming from the muffler. I could put my bare hand on drive shaft and on U joint. Maybe I didn't drive it far enough?

It's an 07 with 52K and since I'm the original owner I technically still have a full drive train warranty. Should I take it to a dealer to have them check it out or will they say too bad since I'm lifted now?

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Anyone have any other thoughts on this issue or experience with a dealer and a lifted Liberty?

mtn_goat · **Posted:** Mon May 09, 2011 1:10 am

Have you had the pcm/transmission flash done? I had a shutter/vibration around the same RPM range. It would get worse anytime I would go uphill at this RPM and my speed at 30-35 mph. It would go away though if I manually downshifted the auto from overdrive to drive or 2nd gear. There is an update for the pcm that will update the shift points in the 42RLE. Your local Jeep dealer can preform this. It cost me about $90 if I remember right. I had this done about 2 months ago and have had no more shutter/vibration problems.

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

mtn_goat-No but I will look in to that. Thanks.

Since this was a TSB they wouldn't have just done it when it was in for service? Looks like the TSB about the flash was put out in 2009. I was getting all of my service done at the dealer for the for the first 36K.

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Dealer is saying it's caused by the angle of the drive shaft and that the only way to fix it is to have a shop that specializes in lifted vehicles change the angle some how. They said they didn't see any info on a PCM flash but if I can find it they will look into it. If anyone has the details on the TSB please post or PM. I'll search a around but I want to find it soon while they still have it in shop. Thanks!

tommudd · **Posted:** Thu May 26, 2011 6:29 pm

Easy thing for them to say that way they don't have to do anything to it!

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Yeah my buddy wondered if they even checked it out or just said "oh, it's lifted that your problem". Actually they did report that they road tested and then they measured the drive shaft angle and said it's 15 degrees and should be like 7-8 degrees. So my buddy finds some internet articles about people lifting vehicles and needed to change their drive shaft angle. I told him I though it was funny that I hadn't ready about that on the forums I read for the standard lifts anyway.

Dealer ended flashing it and it does drive better (shift points?) but still gets the noise or vibration. Guess I'll be getting a second opinion.

BugginKJ · **Joined:** Mon Jul 06, 2009 7:35 pm **Posts:** 4576

bigjimslade wrote:

Dealer is saying it's caused by the angle of the drive shaft and that the only way to fix it is to have a shop that specializes in lifted vehicles change the angle some how. They said they didn't see any info on a PCM flash but if I can find it they will look into it. If anyone has the details on the TSB please post or PM. I'll search a around but I want to find it soon while they still have it in shop. Thanks!

I am using my back up pc so I can't post ya the link. I also have an 07 and am the 2nd owner. I had the torque converter replaced and the flash done for nothing when I pointed it out to the dealer. Search my post's and you'll find the details. :JEEPIN:

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Had u-joints replaced and the it's way better. Is still seems to have a little noise coming on about the same place but maybe that's just normal? Definitely better than it was before. Will be keeping a close eye on it and the mechanic that did the work may look at the angle issue as well since there still seems to be something there. Thankfully he only charged me $50 (sister's friend).

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Resurrecting this as the problem did come back shortly after getting the u-joints replaced. I'm guessing it does have to do with the drive shaft angle change and maybe it's burning out u-joints. I'm going to get back in touch with the guy who changed the u-joints the first time and see if he can find out anything about changing drive shaft angles.

However, I may be getting some Moabs with 245/75 MTR's on them. Since those are an inch taller than my current tires I may need to lower my Liberty down a half inch to get in my garage. My roof bars scrape the molding around my garage door at certain angles as it is. I thought about just removing all the height adders except for 1/8" of clevis to level it. That would lower it down about a full inch all around so basically I would only have the additional height from the springs. Any thoughts on running that height with the new wheels and tires? I know I still need to pound the pinch weld but other than that would the lift of just the OME springs be enough for the larger tires?

If I do lower it a full inch I should be able to enter my garage without any scraping. That's a plus. Can't wait until I get around to buying a new house with a normal sized garage opening.

bigjimslade · **Joined:** Thu Jan 13, 2011 2:37 pm **Posts:** 100

Looks like I'm getting the Moabs!

As soon as I get them I'll schedule a day to lower my Liberty, finally install my LBJ's, pound pinch welds and install my new wheels. :BANANA:

Yep, I'm a little giddy. Also praying that lowering it will get rid of the vibration. How much should I try and sell my factory Liberty wheels for? 4 of which have 245/70-16 Firestone Destination AT's (spare is unused factory tire).

Odd noise/vibration

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