harsh ride/vibration at front of vehicle

[andycook]

I'm still trying to get to the bottom of shuddering/vibration seeming to come from front of our 4runner. I've had the wheels balanced again (not on a stud adaptor as they only had a 5-stud one), no improvement.
In last few months,
1) all suspension ball-joints changed for new (as a pry bar test showed wear),
2) steering damper changed,
3) track-rods ends changed (highlighted in MOT as wearing),
4) idler-arm bushes changed,
5) New front shocks (milners gas - again MOT picked up)
6) new rear coil springs to cure butt sag (rear shocks fine)

I checked yesterday with front-end raised, as soon as I moved either front wheel, the steering wheel moved - so I reckon the idler arm ball-joint and pitman arm are OK.

Front end is actually about 0.3 inch lower than standard ride high quoted in manuals (of 2.3 ") - but the bump stops are well clear of suspension arms.
Tyres running about 30-33psi, have also tried as low as 28 psi - no change

basically get a shimmying/vibration above 50mph worse the faster one goes., it seems to be a lot better on smoother roads, and rough tarmac or 'coarse tarmac' defintely makes it a lot worse
It doesnt give much feedback through steering wheel, which suggests its not wheel balance problem.
The whole vehicle basically shakes, and it can be felt in pedals e.g. accelerator.
It seems to go through phases, at same speeds, getting worse then improving, whether on straights or corners. which is strange that it doesnt happen all the time - like an out of balance wheel would!

I have tried going at different revs, e.g. at 60 mph, the revs are @2300 rpm, in 5th gear, so ive tried going into 4th at same rpm, and it doesnt necessairly shake as much. - so dont think its the drive shafts or u-joints (I have greased all the u-joints.

The tyres are relatively inexpensive knobblies - camac terra 4x4 - i.e. similar tread to BFG's maybe slightly more aggressive, previous owner put them on, they were only about £50 each

Wheel bearings - N/S front slightly loose, O/S front fine - but even when I have tightened up the N/S front one, still get the vibration

any ideas - I dont want to throw anymore money at the problem, until I'm more cert whats causing it...

[rich]

It could be a damaged wheel or an out of shape tyre. Try moving the wheels front to back and see if it goes away / moves.

It might also be sh!te tyres, they are big tyres and they may move about the faster you go on uneven surfaces.

Rich.

[andycook]

thanks Rich
missed that one out - have swapped front & back no improvement

[mart 870]

If its coming through the whole car and its not the wheels how abut the prop shaft, i know others have had a problem with vibration before and they traced it back to the prop loosing its balance weights.

[dirtydog]

my dad just had his wheels balanced as was doing exactly what yours does. it took them 1 1/2 hours to balance all 4 wheels and they said one was a pain! apparently due to the tyres being so big - it causes probs sometimes.

[andycook]

mmm - as a process of elimination, going to take the truck to a scottish outpost of Nene valley offroad, which is 10mins from where I live. Spoke to Stuart there, and he has adaptors for lug-centric balancing, and he specializes in 4x4 wheels and tyres. That should hopefully help or rule out a balancing issue.

[Koi]

mmm - as a process of elimination, going to take the truck to a scottish outpost of Nene valley offroad, which is 10mins from where I live. Spoke to Stuart there, and he has adaptors for lug-centric balancing, and he specializes in 4x4 wheels and tyres. That should hopefully help or rule out a balancing issue.

As a pointer, the garage I had my BFG AT's fitted at said that with the machine running at normal speed with the big tyres it throws out the balance even more. Basically over emphasize any wobble present, so they put bigger weights on and when running on normal use is still out of balance.
He simply spun the wheel by hand, added the weights where needed, job done no wobble at all.

[surffreak]

could also be the discs warped if the go under the specified thickness they have atendancy to warp which could cause the problem. i think i read somewhere that the specs for them are new 21mm replace at 19 mm.

[maacracing]

vibration

I'm still trying to get to the bottom of shuddering/vibration seeming to come from front of our 4runner. I've had the wheels balanced again (not on a stud adaptor as they only had a 5-stud one), no improvement.
In last few months,
1) all suspension ball-joints changed for new (as a pry bar test showed wear),
2) steering damper changed,
3) track-rods ends changed (highlighted in MOT as wearing),
4) idler-arm bushes changed,
5) New front shocks (milners gas - again MOT picked up)
6) new rear coil springs to cure butt sag (rear shocks fine)

I checked yesterday with front-end raised, as soon as I moved either front wheel, the steering wheel moved - so I reckon the idler arm ball-joint and pitman arm are OK.

Front end is actually about 0.3 inch lower than standard ride high quoted in manuals (of 2.3 ") - but the bump stops are well clear of suspension arms.
Tyres running about 30-33psi, have also tried as low as 28 psi - no change

basically get a shimmying/vibration above 50mph worse the faster one goes., it seems to be a lot better on smoother roads, and rough tarmac or 'coarse tarmac' defintely makes it a lot worse
It doesnt give much feedback through steering wheel, which suggests its not wheel balance problem.
The whole vehicle basically shakes, and it can be felt in pedals e.g. accelerator.
It seems to go through phases, at same speeds, getting worse then improving, whether on straights or corners. which is strange that it doesnt happen all the time - like an out of balance wheel would!

I have tried going at different revs, e.g. at 60 mph, the revs are @2300 rpm, in 5th gear, so ive tried going into 4th at same rpm, and it doesnt necessairly shake as much. - so dont think its the drive shafts or u-joints (I have greased all the u-joints.

The tyres are relatively inexpensive knobblies - camac terra 4x4 - i.e. similar tread to BFG's maybe slightly more aggressive, previous owner put them on, they were only about £50 each

Wheel bearings - N/S front slightly loose, O/S front fine - but even when I have tightened up the N/S front one, still get the vibration

any ideas - I dont want to throw anymore money at the problem, until I'm more cert whats causing it...

I had the very same problem with my surf carred all same checks you have
found it was down to the wheel nut tourq settings.
Set mine @110 flbs all OK now.

maac

[TonyN]

Try a dial guage on the wheel rim, and also the tyre if you can, old/cheap tyres often go out of round.

Also make sure the wheel mounting face and backs of wheels are clean and smooth.

[Malenibo]

Traced my vibration down to warped discs. Had them skimed on the vehicle took about two hours and vibration/wobble cured.

[andycook]

surely warped discs would only cause problems on braking?, not moseying along,

did some experiments this morning, on dual carriageway, when vibration/shaking started i lifted off power and pushed clutch in, and shaking persisted, and i tried this on long down-hills, so I guess this may rule out prop-shaft problems?

another thing, is when idling, the whole exhaust system shakes like a mad-man, wonder if that could cause vibration in body at speed, - but lifiting off pwoer should have stopped that

I have attached a picture (found on forum) - it shows a bracket, which the exhausts sits against, I think bracket is attached to gearbox. I am pretty convinced the exhaust us rattling against this bracket - so i might try one of those circular clips (jubille? butterfly?) to clamp the exhaust to this bracket to stop the vibration

UPDATE - had wheels balanced with proper stud mounting,
noticed at time when being done tyre wobbles side to side, i.e. width of tyre varied
still get vibration with correctly balanced wheels,
guy has offered to lend me another set of wheels for a week, to rule out other wheel problems

[andycook]

Is a fraction of mm looseness in rear prop u-joint enough to cause the vibration

Is a fraction of mm looseness in rear prop u-joint enough to cause the vibration?,
just checked it again, and found there is about 0.5mm, maybe more, of nearly imperceptible rotation on u-joint at rear propshaft where it meets rear diff,
is this enough to cause whole vehicle to shake at 60 mph!??
andrew