Bad Vibrations

[Sam Johnson]

Can anyone help?

I have a beautiful 1998 MK4 LS400, which I bought 4 years ago from Lexus Nottingham, with just 22,000 miles on the clock. However, on my very first motorway journey, about a week after purchase, I noticed a trembling vibration travelling through the car and immediately suspected that the wheels needed balancing. I had all the wheels balanced the next day but still no improvement, so I had them balance again at a different garage and again, no joy.

The following week, I took the car back to Lexus where it was inspected for steering or suspension problems. The dealer said that there were no mechanical problems with the car and that the only thing that can explain the vibration is tyre imbalance, so I had them balance all 5-wheels again – still no improvement. I took the car to another Lexus dealer - Bromley in London - and begged for their help but all they could say was that I should not be driving at speeds of 85-95mph. They balanced the wheels but still no different. I was getting desperate now so I decided to change all 5 perfectly good tyres and bought the best high-speed-rated Pirelli tyres I could afford – still no improvement.

After years of balancing and re-balancing (more than £1,000 spent, inclusive of tyres) I was still non-the-wiser as to what could be causing this vibration. Fortunately, about 18-months ago, my need to commute back and forth from London to Manchester ceased following a change of jobs and for the first time since buying the car, I really began to appreciate the Lexus driving experience, albeit at speeds of 50mph or less. I was in love, totally in love and swore that I would do whatever is necessary to rectify this problem. Only problem is, almost 2 more years on and another £1,250 on new tyres and countless balancing, I still have exactly the same problem – no better and no worse?

For those who may think I am being particularly fussy, every front seat passenger in my car to date (when travelling between 85-95mph) have all complained about this juddering through the car. Please someone help me, I have no where else to go and Lexus have disowned me (except for when it come to taking money off me for servicing).

Regards to all,

Sam

[maneesh]

You poor sod! You've been round the houses on this one.

From what you've said, it doesn't sound like a tyre or wheel issue, more like there is an imbalance with the driveshaft. There are a few places that can balance driveshafts or at least get you an accurate diagnosis. Have they checked out all the suspension bushes? Maybe the car was neglected by the previous owner in terms of throwing it around the corners?

These cars run so smooth, that the smallest wear and tear in bushes can throw the balance off.

Have a look on google for driveshaft specialists and perhaps get your suspension checked out.

[Matthew_McNally]

have you checked to make sure your wheels are not buckled?

[ColinBarber]

yes did they check the runout on the wheels or just keep checking the balancing?

You could always just replace the wheels one at a time with the spare - as long as you don't have more than one wheel out you should notice an improvement if it is a wheel.

Otherwise you need to check driveshaft, wheel hubs, suspension bushes.

[Tony-Bones]

I wrote a thread on this topic some time ago, i might be a good read for you!

It's in wheel and tyres, page 4

'Wheel balance'

why is goes wrong

I dont know how to bring threads forward, anyway there it is :D

[ColinBarber]

I wrote a thread on this topic some time ago, i might be a good read for you!

It's in wheel and tyres, page 4

'Wheel balance'

why is goes wrong

I dont know how to bring threads forward, anyway there it is :D

←

here's the link:

http://www.lexusownersclub.co.uk/forum/ind...showtopic=22370

[cleverdick]

You have my sympathy - I went through this with my Mk2 Granada. I lost count of the money I spent on it, but I did improve matters with a remanufactured (and precision balanced) prop from Burgess of Bradford, a pair of new driveshafts and umpteen guibo (doughnut) joints. I also spent ages getting the driveline as straight as possible with a special laser jig that I made, and by packing out the centre bearing support and gearbox mounts I was able to reduce the stress on the doughnut which meant that it lasted six months instead of three. It just went on and on, and in the end I got so fed up with it I sold the car and vowed never to buy another Ford. What attracted me to the LS was that the brochure specifically mentioned the perfectly straight driveline by design. You'd be surprised how many garages, (even transmission 'specialists') have no concept of propshaft alignment, runout or balance. Have you visually inspected the rubber propshaft doughnuts? A split or damaged one of these may well be the cause of your problem and should not be too expensive to fix. It may be helpful too to view the car underneath with it running on a hoist (with safety in mind, of course). Check also that the driveshafts aren't bowed. If all else fails, consider having the wheels balanced ON the car.

[kratbomc]

Can anyone help?

I have a beautiful 1998 MK4 LS400, which I bought 4 years ago from Lexus Nottingham, with just 22,000 miles on the clock. However, on my very first motorway journey, about a week after purchase, I noticed a trembling vibration travelling through the car and immediately suspected that the wheels needed balancing. I had all the wheels balanced the next day but still no improvement, so I had them balance again at a different garage and again, no joy.

The following week, I took the car back to Lexus where it was inspected for steering or suspension problems. The dealer said that there were no mechanical problems with the car and that the only thing that can explain the vibration is tyre imbalance, so I had them balance all 5-wheels again – still no improvement. I took the car to another Lexus dealer - Bromley in London - and begged for their help but all they could say was that I should not be driving at speeds of 85-95mph. They balanced the wheels but still no different. I was getting desperate now so I decided to change all 5 perfectly good tyres and bought the best high-speed-rated Pirelli tyres I could afford – still no improvement.

After years of balancing and re-balancing (more than £1,000 spent, inclusive of tyres) I was still non-the-wiser as to what could be causing this vibration. Fortunately, about 18-months ago, my need to commute back and forth from London to Manchester ceased following a change of jobs and for the first time since buying the car, I really began to appreciate the Lexus driving experience, albeit at speeds of 50mph or less. I was in love, totally in love and swore that I would do whatever is necessary to rectify this problem. Only problem is, almost 2 more years on and another £1,250 on new tyres and countless balancing, I still have exactly the same problem – no better and no worse?

For those who may think I am being particularly fussy, every front seat passenger in my car to date (when travelling between 85-95mph) have all complained about this juddering through the car. Please someone help me, I have no where else to go and Lexus have disowned me (except for when it come to taking money off me for servicing).

Regards to all,

Sam

Just a guess it could be similar to my trouble...

My 1990 LS400 has 170k miles on it. Just recently, my rear end has been vibrating at high speeds. It is intermittent and my mechanics have had trouble replicating it on their test drives. When I slow down and then stop, and then set off again at low speeds, the vibration goes away. But when I go back to 50+ MPH there it is again.

The first time it happened, I thought I had a flat tire. Then I thought it might be a wheel bearing but they now tell me they believe my ABS is switching on when it shouldn't be.

I am asking around to see if I can just disable the ABS and do without it? I don't feel I need ABS but don't want to do anything dangerous. If it's OK to disable, I need to learn how I do that. At the least -- even if it's just for trouble-shooting purposes -- I'll know for sure if that is the cause of my vibrations.

What do you think?

[Dfgivens]

Hello gentlemen,

I experienced (and solved) similar haunting vibrations in my '95 LS400. At 55K a new set of Goodyears where put on the car, and as they broke in odd speed-sensitve vibrations would occur: front wheel hop, rear wheel hop, heal/toe oscillations, pulling in either direction,...you name it! A different problem would start as old ones faded away. It was not shock, spring, balance, or inflation problems.

I tried everything to solve the problems, and consulted countless "experts" in vain. Finally I realized the problem wasn't the suspension, it was the side-wall stiffness in the Goodyears. Temperature, air pressure, and road condition variables mask the problem, but replacing the tires with BFGoodrichs returned the car to its original ride!

Many tires that are claimed to be rated correctly for this car simply are NOT. This car demands a very stiff sidewall, so I'd look there for the solution.

Best of luck!

Dave

[GoldfingerLS]

Hi Sam,

I just noticed your post. The symptoms and the amount of vibration you describe (i.e. even the passenger notices it) is probably too much to attribute to just tyre/wheel run-out (i.e. aligning the 'dot' on the tyre and rim). This is one possible cause, but it seems you have pretty much eliminated the tyre/wheel possibility.

Does the vibration happen when you are braking ? or does it happen even if you don't have your foot on the brake pedal ? does it get worse if you brake ?

[Owen LS400]

Hi Guys, newbie here. :)

Sorry to dig up an old topic, but my 91 Ls400 with 132k on the clock and running the standard 15" alloys has the same problem.

Above 80mph on the motorway the steering wheel starts vibrating like mad, you can also feel the vibrations through the floor and the seat. The vibrations i assume originating from the wheels or suspension. As a side note, over 100mph (which i know i shouldnt be doing ) and the vibrations seem to lessen. It ruins the otherwise enjoyable experience of the Lex, which with the exception of this problem loves a long motorway jaunt.

[Y2Kanjar]

i had the same problem.... it was the lower nearside arm... warn away...

might wanna look at that...

(mondeo)

[GoldfingerLS]

Hi Guys, newbie here. :)

Sorry to dig up an old topic, but my 91 Ls400 with 132k on the clock and running the standard 15" alloys has the same problem.

Above 80mph on the motorway the steering wheel starts vibrating like mad, you can also feel the vibrations through the floor and the seat. The vibrations i assume originating from the wheels or suspension. As a side note, over 100mph (which i know i shouldnt be doing ) and the vibrations seem to lessen. It ruins the otherwise enjoyable experience of the Lex, which with the exception of this problem loves a long motorway jaunt.

Hi Owen,

If the shudder is only happening when you apply the brakes it could indicate warped discs. However from reading around this forum, a common problem on the LS400 after 100K is the upper suspension arms and /or possibly the lower ball joints. A gentleman on this forum recently posted that his MOT failed due to this reason. It might be worth having this checked out.