Shake / wobble at 100

[stirlo97]

Good evening everyone,

I have made a couple of posts about this in the past but my problem remains after a number of suggested solutions have been implemented to no effect.

As the title suggests, I am getting a constant shake throughout the car at around 100kph. It seems to be slightly worse under heavy acceleration, however doesnt seem to change wether there is throttle inpput or in neutral rolling at the same speeel. Weight in the back and steering angle / input has no effect either. The shake was coming through the wheel however a recent tyre change and correct balance and alignment seems to have sorted out the shake at the wheel but the car still shakes.

Here is the list of things I have done to try and rectify the problem:

- Lifted w/ a Formula 2" lift (cheap shit I know but seemed to ride alot better when done ~30k kms ago)
- Changed cheap steel rims to 17x9 PCOR +10 Alloys
- Changed from a 265/65/17 Maxxis Bravo AT to 265/70/17 Kumho AT's (wheel alignment and balance sorted out steering wheel shake as mentioned above)
- Replaced lower control arm bushes after a suspension check at Fulcrum revealed they were worn.
- Hub centric rings to correctly align wheels to hubs
- Replaced 2 universal joints in the rear drive shaft
- Replaced centre bearing and spaced accordingly
- Replaced front rotors with DBA T3 rotors
- 2 degree castor wedges under leaf springs to alleviate driveline vibration after lifting
- Recently changed engine, diffs, transfer case and transmission fluids and lubricated all driveline and suspension components.

I intended on changing out steering rack ends, tie rod ends, upper and lower ball joints and sway bar link bushes however after the recent tyre change that has eliminated the steering wheel shake, it leads me to believe that the shake is not coming through the front end.

My course of action has been to just keep replacing bits unitl it goes away, however I am at the point where I dont have much else to replace that isn't going to cost me an arm and a leg.

The car has done 201K kms, and does mostly highway driving with the occasional beach trip / weekend camping trip offroad. No hard tracks or bush bashing has ever been done in it.

If anyone has had a similar experience or any suggestions on where to go next I would greatly appreciate your input.

Cheers

[Rob_Wood]

After doing all that you'd think it'd be sorted. About the only thing left is to take it to a panel-beater, ask them to put it on the rack and check how straight the chassis is.
Might not have had a hit ... That you know of, but I guess you never really know.
Just a thought.

[dave g]

Check the tail shaft is in sink at the universals

[Rob_Wood]

Check the tail shaft is in sink at the universals

Yeah, my first thoughts were wheel balance, tail shaft balance and then crank balance, but he said he'd done the first 2.and a crank balance wouldn't just be at 100k, it be (at best) at a set.amount of revs, regardless of which gear you're in, so I went to the chassis. Certainly an odd one.
Rear wheel bearing? Just thinking out loud now. For a shake or wobble to develop at a particular speed, it's gotta be a rotating component that isn't dependant on rpm, but rather on the speed of the vehicle.
Gear box? Grasping at straws now, I know, but hey!

[dave g]

All so check for a bent axle

[Rob_Wood]

All so check for a bent axle

Yeah, buckled rims would normally be picked up on a balance. The list goes on.

[stirlo97]

All so check for a bent axle

If I had a bent axle I'd be getting a consistent shake, not just at 100

[Rob_Wood]

All so check for a bent axle

If I had a bent axle I'd be getting a consistent shake, not just at 100

Never say never, depends exactly where on the axle and how bad is the bend.a very slight bend in an old troopy wasn't enough for a shake or wobble, but popped out the cone washer bolts often enough.

[dave g]

100 k could be the trigger point to show up as it is speed related

[Rob_Wood]

100 k could be the trigger point to show up as it is speed related

Agreed, anyone who's had a wheel out of balance can attest to reaching a given speed at which the shaking starts and may even have experienced a higher speed at which the shaking seems to subside.

[stirlo97]

100 k could be the trigger point to show up as it is speed related

Agreed, anyone who's had a wheel out of balance can attest to reaching a given speed at which the shaking starts and may even have experienced a higher speed at which the shaking seems to subside.

Yeah fair point. In my mind wheel balance / driveshaft balance is more of a harmonic resonance type thing that would manifest at X speed... whereas if something isn't spinning in a perfect circle (ie bent axle / tyres out of round) you'd experience that vibration at all speeds.

At this point I'm probably just going to take it to somewhere reputable and ask them to run a fine tooth comb over the car until they find the problem.

Thanks for your input folks

[Rob_Wood]

100 k could be the trigger point to show up as it is speed related

Agreed, anyone who's had a wheel out of balance can attest to reaching a given speed at which the shaking starts and may even have experienced a higher speed at which the shaking seems to subside.

Yeah fair point. In my mind wheel balance / driveshaft balance is more of a harmonic resonance type thing that would manifest at X speed... whereas if something isn't spinning in a perfect circle (ie bent axle / tyres out of round) you'd experience that vibration at all speeds.

At this point I'm probably just going to take it to somewhere reputable and ask them to run a fine tooth comb over the car until they find the problem.

Thanks for your input folks

Please let us know how it goes. Be interested to find out the results.