Dropped my QC, now have bad vibration

BlackKnight

BlackKnight

Full Access Member
Joined
Nov 6, 2006
Messages
660
Reaction score
9
Location
Orange County, CA
Finally got around to installing my X-metal drop kit on my 06 QC with the help of Pat (RedSrt007) and John (JRSViper) a few weekends ago. Big thanks go out to these guys for helping and getting beat up, bruised and bloody with me; essentially sacrificing themselves for the cause. Guys I still owe you some steaks and beers :eating: :cheers:
But now I have a vibration coming from the rear end when I accelerate from a complete stop. I start to feel it around 5-10mph no matter if ease into it or romp on it; its actually really rough when I romp on it so none of that going on. The pinion angle at the rear diff. was +3 when we first finished installing the drop kit. We then lowered it to -3 but no change and now its at -5 and the vibration is still there. What am I missing:dontknow: ? Anyone else run into this problem? I called Boomer and he suggested installing 2, 1/8 shims under each of the rear tranny mounting bolts. What should be the correct pinion angle? I did about a 1in drop in the front and the rear dropped about 4in to level the truck out nicely. Any help would be much appreciated. Heres some pics of what the beast looks like post drop.
 
Remove those ugly azzed stickers, they are causing the vibes :D

Boomer's pretty smart, try the shims....

My thought, check all your driveline stuff including the driveshaft....a vibration at 5-10mph, easing into the throttle, is very unnerving....also, check all the bolts, make sure everything it tight....

All I can think of for now :confused:
 
when i did my 04 hemi qc i had to shim the tranny to get the right angle.don`t know the pinion angle but the 1/8" shims sounds about right.
 
Is a 1/4 of an inch that dramatic of a change the vibration could possibly stop? Kinda seems too easy of a fix ya know but I'll try it this weekend hopefully.
 
If any of you guys with a QC, lowered or stock, could check your pinion angle while the truck is sitting on the ground that would be awesome.:D :D
 
O GREAT,SOMETHING ELSE TO WORRY ABOUT WHEN I LOWER MY TRUCK!!!
GOOD LUCK BRO,I AM NO HELP IN HOW TO/WHY, BUT INTERESTED IN THE RESULTS!!
 
i had the same thing on my 2005 QC when i put the lowering kit on,and it truned out to be the pinion angle....( as boomer had told me on the phone that is what it was) i had the guy change it 2 times then he got it right.
 
Yes you must get your pinion angle just right.

If you look at the top of the rear axle center housing you will see a flat spot, the flat spot should be level with the ground.

If it angles up or down you will get a vibration.


Bill.
 
I have no idea what is wrong... but it sure does look nice! :D :rock:

Did you get a front alignment yet? The front looks to have WAY too much camber. :( :dontknow:
 
you gotta check the angle at the rear diff as well as the tranny. U-joints do not rotate at a constant velocity when they are at any angle, so the more angle you have the worse it gets. too bad they don't put CV joints on the drive shaft!

good luck~
Mike
 
oh by the way, looks nice! did you raise the rear with the longer shackles or did you leave it at 4" drop? It may just be a lil too low.

~mike~
 
Did you get a front alignment yet? The front looks to have WAY too much camber. :( :dontknow:[/QUOTE]

Yeah the front end alignment was done. The adjustments are on the bottom of the a-arms and they maxed them out as well as drilled out the top mounting holes a little bit as well.
 
AWDisuzu said:
oh by the way, looks nice! did you raise the rear with the longer shackles or did you leave it at 4" drop? It may just be a lil too low.

~mike~
Click to expand...

I left it at the 4in drop. Do you think using the longer shackles would help out with the vibration?
 
fast fred said:
i had the same thing on my 2005 QC when i put the lowering kit on,and it truned out to be the pinion angle....( as boomer had told me on the phone that is what it was) i had the guy change it 2 times then he got it right.
Click to expand...

How low did you drop yours Fred?
 
thanks includemeout that's what I was looking for!

the QC is tough because of the 2 piece driveshaft too....
 
I have the same vibration (accelerating from a stop) as well at around 2100 rpm's. My angle has been at 0 to -4 and still the same thing. I was also told to try the shims under the tranny bolts, but haven't done it.
 
You must log in or register to reply here.

Latest posts

Support Us

Become A Supporting Member Today!

Click Here For Details

Random Media

Bills Truck
image
Texas Rammers Club - Founded in 2004... All Bad Ass Rams are welcomed!
image
Back
Top