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.

[stirlo97]

UPDATE

Since posting I have replaced both front CV's, wheel bearings, hubs, steering arms, sway bar links, lower control arms and had a wheel alignment.

The shake remains.

Pretty much the only thing left is the tailshaft or something internal inside diffs / engines etc (hopefully not likely)

[Gipsy]

Is it a manual? If so have you changed the clutch/pressure plate? They can be out of balance, resonance can kick in at a particular speed.
It seems that you have already changed all the usual suspects but sometimes it's very difficult to find gremlins like you described. Although a clutch balance issue would show when you are in neutral at 100k as the engine is running down in revs. Gearbox may have a shaft bent but that's not likely. Tailshaft is next on the list... Bent or universal gone. My old 80series landcruiser had universal gone in the front driveshaft and shook like hell... New shaft fixed it. Give the shaft a twist and check for movement, it will show up a dud universal.
Good luck finding it, you seem determined to get to the bottom of it but sometimes it just is!

[stirlo97]

Is it a manual? If so have you changed the clutch/pressure plate? They can be out of balance, resonance can kick in at a particular speed.
It seems that you have already changed all the usual suspects but sometimes it's very difficult to find gremlins like you described. Although a clutch balance issue would show when you are in neutral at 100k as the engine is running down in revs. Gearbox may have a shaft bent but that's not likely. Tailshaft is next on the list... Bent or universal gone. My old 80series landcruiser had universal gone in the front driveshaft and shook like hell... New shaft fixed it. Give the shaft a twist and check for movement, it will show up a dud universal.
Good luck finding it, you seem determined to get to the bottom of it but sometimes it just is!

Hey mate,

It's an auto. And I had 2 uni joints replaced in the rear shaft about 2 years ago along with a centre bearing. That seemed to fix it for a while however a few weeks ago the centre bearing let go and had to replace that again. There isn't any movement in the driveshaft and everything seemed to check out.

I've got it booked in to get a new driveshaft as it's pretty much the only thing left at this point.

It's probably driving the best it ever has at the moment but I still get a bit of a jiggle around 100 but not as bad as it was.

[Rob_Wood]

Centre Bearing?
In my old International, the.centre.bearing also supported a short shaft between the transfer case and the tail shaft to help with a slight offset and house a tailshaft handbrake.
I mention this because if your centre bearing has let go then that shaft might need checking for straightness and balance ... Especially if when it let go it was able to slap around then this shaft might have been put slightly off kilter. Just a thought.

[Chopps]

Worth a check to see if your model/year had its Tailshaft centre bearing support bracket has been replaced

viewtopic.php?f=30&t=7119

[dave g]

Strirlo97
You haven't said if you have a suspension upgrade if you have it mit be you need to put a spacers a the centre bearing to bring it in line as it is not very common to change centre bearing that often.

[ptommo59]

As others have said check the phasing on the driveshaft is correct and you mentioned putting 2 degree spacers in, maybe check that they were put in the right side of diff to get close to equal u-joint operating angles as if on wrong side can make the difference in angles and harmonic vibration worse.

[dave g]

I need a new pear of glasses with a 2in lift you should not need a wedges to me it looks like the centre bearing and universal alignment is not in sink.