Shaky start from stop after lift/tires

[nmadd118]

I just lifted my KJ and 245/75's and I've noticed now there is somewhat of a shaky start when I initially accelerate from a stop, sort of like a small vibration that I'm probably overly fixated on -- is this just my more aggressive now tires and normal or is it possibly something with my alignment?

I had my alignment done and noticed it still pulls to the left a bit so I'm going to bring it back to the shop and have them look at it adjusting it.

But, I never had this before the install was done.

Thanks in advance.

 

[rockymountain]

Done it since lift install or tire install?

Could be your u-joints. Now they're at a different angle. I know for a while mine would shake the rearview mirror so bad coming off an exit ramp with my foot stuffed in it that I couldn't see behind me.

Post up your alignment sheet when you get a chance.

 

[nmadd118]

Well I put the tires on/alignment the following day but I can't remember exactly if it happened the few times it was driven before the tires.. Will post up my alignment specs soon.. It doesn't sound like anything to the extent of yours -- what was the fix?

 

[rockymountain]

It still does it a little bit, but since then I've put new greaseable u-joints on and have lowered it some. Mine does it most when at WOT when it shifts to second. It is a lot better since then and I think really it was making it lower and u-joints 50/50. I've mentioned before my KJ does not like being over 22". Seems to be just me though as it's probably I don't like the way it feels being over 22".

Where are your measurments?

 

[TwoBobsKJ]

Mine did the same thing - didn't know the cause but I had already planned to replace both the right & left CV axles and intermediate shaft. As soon as I did the vibrations went away. Try putting your Jeep in 4WD and accelerate. If you feel the vibrations strongly in the steering wheel it's the front CV's.

Guess the additional height was a bit much for worn CV's. I think rockymountain's solution with the rear u-joint is a good place to look too.

Bob

 

[nmadd118]

it's actually more of a wobbly feeling than a vibration - any changes to thoughts there? almost like something is off balance - should also mention i have painted wheels and to avoid taking my balancing weight off (painted after initial balancing) the shop who put the tires on put a counter balance on the inside.. I'm wondering if there's too much weight or something that's causing it

 

[TwoBobsKJ]

The wobbly sensation is what I experienced with the front CV axles. Wobble frequency changes with speed - more vibration than wobble as you go faster.

Depending on the number of miles on your KJ it may be a good time to replace the front CV axles and intermediate shaft anyway. Only use NAPA remanufactured units - they're the correct length. After the core charge is refunded to you they're about $55-$60 each. The intermediate shaft is around $120.

Bob

 

[nmadd118]

only 55k miles so Im tempted to say theyre not worn out but I could be wrong

 

[TwoBobsKJ]

Have you put it in 4WD and accelerated from a stop? If you feel the wobble in the steering wheel then it's the CV's.

Bob

 

[nmadd118]

will try that today - thanks for help

 

[ThunderbirdJunkie]

Are you sure your wheels are bolted properly to the hub?
What tires do you have now and what did you have before?

 

[nmadd118]

tried the 4wd - seemed to be less noticeable than in 2wd

i had stock before i think 235/70 goodyear wrangler sra

now have 245/75 goodyear wrangler authority

i used an impact gun on the lugs so i hope so!

 

[rockymountain]

i used an impact gun on the lugs so i hope so!

nono.gif

 

[ThunderbirdJunkie]

now have 245/75 goodyear wrangler authority

Square tires...check.

How many miles are on this Jeep anyway?

 

[nmadd118]

55k

 

[moparman]

Maybe it's coming from the rear? What about the recall for the rear lower control arms?

 

[nmadd118]

had them replaced a few weeks before the lift/tires went on and there was nothing

 

[Ry' N Jen]

nono.gif

Ya, best to use a manual torque wrench and torque the wheels to 85 foot pounds/115 Nm of torque.
I use a digitally adjustable electric impact gun which I set to 85 foot pounds of torque.
I've double and triple checked it against a manual torque wrench and it's spot on!

 

[nmadd118]

it's very subtle.. maybe Im just being neurotic but it's definitely noticable.. once Im going over 5mph it goes away completely.. anybody think it's vibration just from the tires getting rolling? could it be something with the alignment - had it aligned right after the lift but noticed on the highway it pulls slightly to the left still

 

[rockymountain]

is it like a shake that would rattle change in your cup holder type of shake? Then yes it is probably the edges of those tires. Mine would vibrate something fierce going under 5 mph with my BFG KMs. It still does with my duratracs, but it is a finer vibration because the tread is not as crazy.

... what is your camber set at?