Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

1 - 11 of 11 Posts

·
Registered
2002 chevy trailblazer_ls
Joined
·
7 Posts
Discussion Starter #1
I Have put a smaxx 2.5 front and 1.5 rear lift on my 02.
since the instalation i have a vibration that feels like it is the rear or possibly u joints. will the lift cause a vibration by changing the drive shaft pitch???????? :bonk: the vibration accures from 40 to 50 mph and goes away the faster i go. the vibration seems to sound and feel like a helocopter type noise. i am baffled i checked the tires and they are fine the wheels are torqued as well???
HELP PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 

·
Banned
2004 gmc
Joined
·
26,181 Posts
Don't think anyone with a lift ever experienced exactly that problem. Even with 4" or more lift in the back, U-joints haven't been an issue.

I would swap tires front to back just to see if the problem changes at all. Then put the entire vehicle up on good jack stands and run it in the air and look for vibrating parts. The front tires won't spin in the air unless you put it in 4HI, so try 2WD first, then 4HI. Or bring it to a shop you trust.

Could any wheel balance weights have fallen off when you put in the lift? Any mud inside the wheels or on the rotating parts? Any offroading since the installation that could have bent the driveshaft?

Did you put in new shocks with the lift? How many miles total? Changed the various fluids? Check for loose tie rod ends while the front was in the air?
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
7 Posts
Discussion Starter #3
The biggest problem is I do not trust anyone in my area so I do all the work but alignments myself. The installation was easy to me and I tried to be as careful as possible. I have not done any off roading since or before my lift because I bought the truck and immediately changed it after driving home from the dealer. On the way home and running around for a day I did not feel any type of vibrations. The wheels are clean and the balancers are ok. I called Larry from suspension maxx and he suggested running the vehicle on stands under the rear end so the suspension was loaded and I can seem to feel the issue or it is very very minor. I am going to lie under the truck and watch the drive shaft to see if it looks bent or vibrates. While driving I can feel the vibration more when I am lightly touching the gas and when I let off or put it neutral it seems to dissipate. I can set my hand on the back set and feel it is coming from the rear and other then that I am lost.

p.s.
sweet Envoy
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
7 Posts
Discussion Starter #4
Also the truck has 75000 miles on it and I replaced the front struts but not the rear shocks i figured they were simple and i could do it anytime.
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
331 Posts
Dumb question

It's a dumb question but it needs to be put out there lol. You had it aligned after you put the lift in right? Even marking where it should be you can not get it exactly where it should. The vibration could be the back tires trying to go different directions.
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
7 Posts
Discussion Starter #6
It was aligned after the lift of course and the vibration was there before and after the alignment.
 

·
Registered
2006 chevy trailblazer_lt
Joined
·
1,055 Posts
Can you confirm if you get the vibration in 2WD or only when in 4WD.

I have never had a vibration with the rear axle and I think I am approaching the safe limit for driveshaft angle.

The front however has always had a slight vibration when on pavement and using AWD or 4WD. I don't drive on pavement with the front engaged very much. Usually only in the winter with slippery conditions on the roads up here.

Under those conditions, I get a bit of a vibration when accelerating, I would say between 10 and 20 mph.

AG
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
7 Posts
Discussion Starter #9
reply

I get the vibration in 2 wd. It starts at 40mph and dissipates at 50mph. 2 days ago I removed the drive shaft and found the front u joint was a tiny, tiny bit loose but that was all. I rotated the drive 180 degrees and the vibration changed to start at 48 and continue to 60mph. by moving the position it changed the characteristics of the vibration. The only thing I can think of is the drive shaft is not balanced for some reason. Why it would not happen before the lift is beyond me. How much rear lift are you currently running and do you or have you had any changes since lifting the truck??
Thanks Ray
 

·
Registered
2002 chevy trailblazer_ls
Joined
·
4,125 Posts
The vibration could be the back tires trying to go different directions.
There is no factory adjustment for the rear tires and they don't get to far misaligned through time either.





Kinda seems like the rear wheels aren't balanced properly. Have you tried rotating them front to back to see if the vibration moves to the front.
 

·
Registered
2006 chevy trailblazer_lt
Joined
·
1,055 Posts
I get the vibration in 2 wd. It starts at 40mph and dissipates at 50mph. 2 days ago I removed the drive shaft and found the front u joint was a tiny, tiny bit loose but that was all. I rotated the drive 180 degrees and the vibration changed to start at 48 and continue to 60mph. by moving the position it changed the characteristics of the vibration. The only thing I can think of is the drive shaft is not balanced for some reason. Why it would not happen before the lift is beyond me. How much rear lift are you currently running and do you or have you had any changes since lifting the truck??
Thanks Ray
I am using lift springs for a Tahoe/Yukon from SkyJacker. Because they are stiffer than our stock, I get a lift of 4 inches. Never had a problem with vibration on the rear.

Did you go over any obstacles and maybe bump the driveshaft? Maybe its slightly dinged which could throw it out of balance ...

AG
 
1 - 11 of 11 Posts
Top