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Bad vibrations

goodoldboy

Well-Known Member
Joined
Apr 30, 2010
Messages
1,630
as opposed to good vibes... Passengers tell me its not that bad but im pulling out what little hair i have left.
Its a KZJ 95 auto 203 000 miles 265770 Cooper AT3s every suspension bush has been replaced , top & bottom ball joints & most if not all of the UJs . My mechanic has had the props off & says he can find no play.The steering rack has just been out to fix a leak & its all good , no issues with the bushes.A steering rack inner end joint has been replaced & this caused wear on about 20% of the tyre.The fronts were worn quite a bit more than the rears - 8 MM tread left as opposed to about 12.The front tyres are now on the back.The front outer CVs have been done recently & a leak on the diff - where the driveshaft goes in has been done.It was weeping as opposed to pissing out & my mechanic said the over half a litre (estimated) of oil came out & was pretty clean.
It seems to me that the vibe is there from low speed & is worse at 60 MPH above & below this speed , under load its hardly noticeable , of course on the flat with wind resistance its under load. The worst vibes are on lifting off the throttle , especially going down hill .On heavy breaking its especially bad with some judder felt through the steering wheel. to me it also seem worse on left handers. the spannerman is thinks its a badly worn tyre but im not so sure.My mates at the tyreshop say that if its the carcase badly out of balance the vibes would increase with speed - i tend to agree with them. My own suspicion falls on the front diff , maybe one of the bearing shot as that might explain my feeling that the vibes are worse on LH bends , the body roll unloading one side , a bit like a wheel bearing .There is noticeable backlash in the transmission but you have to be quite heavy lifting on/off the throttel to provoke it - its more of a mild thump than a massive clonk or as sever as a badly worn UJ. Alonso is a good mechanic , old school & trustwothy - he said that repairing the steering rack leak was easy & quick & only booked down an hour to change the cam belt - so any input from the club would be welcome.
 
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Badly worn tyres sounds plausible. Did the vibe change when you swapped the fronts to the rear? I had a Trooper with a hard-to-trace vibe (almost a 'shudder' at times) and it was eventually found to be one tyre that had gone out of round. Swapping the wheels around changed the nature of the vibe and allowed me to isolate the cause to the wheels/tyres, and then it was a matter of close examination of the tyres. It could also be a rim I guess, but tyre would be my first guess.
 
Tyre was my gut reaction (without reading your whole post tbh). I've had them go out of round too. Jacked up the whole car and ran it in gear. The ovality was striking.
 
Badly worn tyres sounds plausible....
I'm with Dave. I had a wobble that became apparent at 60mph which resulted in the passenger seat wobbling. Cancelled out above and below this speed. Had the balance of the wheels checked and was assured all was ok. Started to think it was a UJ with play. It wasn't until I've just had BF Goodrich AT's put on that the vibration disappeared. So, it appears to have been a crap old tire after all.......
 
If you search the forum hard enough you might find someone who had the same maddening problem a few years ago who finally got his answer by weighing each wheel and finding one tyre was heavier than the rest :crazy:
 
If you search the forum hard enough you might find someone who had the same maddening problem a few years ago who finally got his answer by weighing each wheel and finding one tyre was heavier than the rest :crazy:
yes Shayne I did see that.the vibes do seem better with swapping the tyres round.the rims are stock Toyota alloys , un damaged.so I might go for 2x New tyres €116 each fitted here
 
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If you search the forum hard enough you might find someone who had the same maddening problem a few years ago who finally got his answer by weighing each wheel and finding one tyre was heavier than the rest :crazy:

That was me Shayne, on a 200 that was pulling to the N/S. Changing the wheels front to back cured the problem but it wasn't a vibration problem.
 
It's always handy, if some are available, to do a complete wheel-set swap with someone with a similar truck, just to see if it is wheel/tyre related, which would eliminate chasing your tail on other faults.

Maybe there's a club member that would be able to do a swap for an hour for the purposes of elimination.

Tyres can develop ovalisation, or flat-spots, and they're not necessarily visible, only measurable, either by dimension or mass-shift.

Many of these faults simply can't be detected by balancing or measuring, which makes it almost impossible to fault-find without eliminating them all from the equation (by a trial swap, for example). JMO
 
I think you might have something there Clive.There is another 95 in Alonsos garage at the mo having the steering pump fixed so ill ask him on Monday if the owner would lend me the wheels for an hour or so.as for the tyre balance M/C Flint I live in a very rural , isolated place - the nearest set or traffic lights at 50 KM away - so I'm not hopefully on that one but thanks anyway.The idea that a tyre acts differently under load is sound I think but although a consensus is building I still think there could be something amiss in one of the diff bearings.also it could be the result of more than one thing
 
If you do manage to borrow a set of wheels, then at least, if the problem persists, you know it's not the tyres.
 
Jack all four corners up and drive it, you will see any runout on the tyres straight away, be carefully it doesn't fall off the jack..... the result won't be pretty!
 
I wonder if a shot of OKO in each tyre would sort it out ?
 
:text-+1: On jacking up. It didn't take long when I did it and was so obvious once it was in the air that both rear tyres were seriously out of round. I could hardly believe it.
 
Just got back from the garage & the vibration is still there - Bugger & feck but we found slight play in a rear UJ & a noisy front wheel bearing.Also some noise from the back end that could be a diff pinion bearing.None of this was apparent before but today we had a look after a road test when everything was warmed up.I'll order the bits tomorrow & Alonso will have a further look at the rear diff when the prop is off.my thoughts from the start were that it's a UJ but with everything tight on inspection it seems that checking immediately after a road test may be helpful....?
 
Just got back from the garage & the vibration is still there - Bugger & feck but we found slight play in a rear UJ & a noisy front wheel bearing.Also some noise from the back end that could be a diff pinion bearing.None of this was apparent before but today we had a look after a road test when everything was warmed up.I'll order the bits tomorrow & Alonso will have a further look at the rear diff when the prop is off.my thoughts from the start were that it's a UJ but with everything tight on inspection it seems that checking immediately after a road test may be helpful....?

Sometimes it is. I nagged my service for ages suspecting a UJ, but "they knew best" saying all ok.

But, I had 2 dry bearings next to each other out of the 4 on the rear end of the rear prop. They changed it and it was like driving a different truck, and a newer one at that!

I'm not suggesting it's the end of your troubles, but it can make a big difference. All these little niggles seem to join hands on transmissions, giving asymptoms of a bigger problem.
 
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