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Vehicle & Technical => Jeep => Topic started by: mgilbert on March 22, 2007, 14:31:08

Title: Engine noise after suspension lift?
Post by: mgilbert on March 22, 2007, 14:31:08
Hello - Just had 2" suspension lift (budget boost) to 04 Grand Cherokee. After fitting, I'm getting a rubbing kind of noise coming from front. The noise creeps in from about 20mph and gradually gets louder as road speed increases. At 70mph it's VERY loud.

Tracking and wheel alignment all check out ok. No death wobble or vibration either. The noise "does" disappear (regardless of speed) if I ease off on the throttle.

After endless web checking I need everything from a greased control arm through to a new front prop shaft. It must be something stupid.

Anyone else had a similar experience? Jeep has only done 27k miles so wearing of joints unlikely?

Thanks!
Title: Engine noise after suspension lift?
Post by: skip on March 22, 2007, 17:55:04
Sounds like the lift has put more strain on the front pinion bearing which could be worn, but that's only a wild guess on my part.

 it's very tricky to even try to diagnose a fault like this, i've given up trying to find the cause of the vibes on my xj.
Title: Engine noise after suspension lift?
Post by: Bishops Finger on March 22, 2007, 19:11:50
Have you tried sites like
NAGCA
Rocznruts
or possibly had a chat with FTE or MDG off road here in the UK who have both I think lifted Jeeps
Title: Engine noise after suspension lift?
Post by: xj.jeeper on March 22, 2007, 19:21:20
Quote from: "Bishops Finger"
Have you tried sites like
NAGCA
Rocznruts
or possibly had a chat with FTE or MDG off road here in the UK who have both I think lifted Jeeps


What's Rocznruts ?  :lol:
Title: Engine noise after suspension lift?
Post by: Bishops Finger on March 22, 2007, 22:23:35
soz ..had a bad day....http://www.rockznrutz.com/forum/index.php
Title: Engine noise after suspension lift?
Post by: mgilbert on March 23, 2007, 09:46:53
All - thanks for your input so far. I've also been reading that having had a suspension lift, the front axle can go out of line by a 1/4 inch or so and needs lining back up with the trac bar.

Is this true? How would lifting the body suddenly make the axle drag to the left/right. The sound I have does have the feeling that the front prop shaft is binding somewhere. Perhaps this is the trouble I've got.
Title: Engine noise after suspension lift?
Post by: greasemonkey on March 23, 2007, 10:18:33
HI
if the lift is such that the u/j has reached it's max angle then it will rub
check it out by looking for new metal or rub marks
i don't think 2 inches will make a difference though but worth looking
also check the compression joint is not out by too much
thats the splined bit
if you have any other questions i have a friend just done a complete
live hylux axel conversion to a frontera so he knows a thing or two
cheers
GM
Title: Engine noise after suspension lift?
Post by: tim_aka_tim on March 23, 2007, 13:23:24
Quote from: "mgilbert"
I've also been reading that having had a suspension lift, the front axle can go out of line by a 1/4 inch or so and needs lining back up with the trac bar.

Is this true? How would lifting the body suddenly make the axle drag to the left/right.


A little difficult to explain without a diagram, so I wont. Have a look here on wikipedia at the Panhard rod entry. http://en.wikipedia.org/wiki/Panhard_rod That should make it clearer why a lift makes the axle kick over.
Title: Engine noise after suspension lift?
Post by: mgilbert on March 23, 2007, 14:24:08
Thanks Tim, Ah, I see now thanks. Raising the body then has a proportional effect to the angle of the trac bar. The higher the angle of the trac bar, the more axle shift will occur (jeez, I sound like a mad professor).

I know for sure the trac bar wasn't adjusted, maybe all I have a shifted axle which is causing a bind on the prop shaft. I'm assuming the stock trac bar can actually be altered to realign the axle?

Thanks - Mark
Title: Engine noise after suspension lift?
Post by: tim_aka_tim on March 23, 2007, 14:55:30
Quote from: "mgilbert"
Thanks Tim, Ah, I see now thanks. Raising the body then has a proportional effect to the angle of the trac bar. The higher the angle of the trac bar, the more axle shift will occur


Presactly. I had to replace mine with an adjustable one, cus the stock one was just too short, but you should get away with the stock one with a 2" lift.
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