Violently vibrating ls400!

[Matt1986]

So the last couple of times I've driven the ls400 it's fine to start with but after about a mile a vibration from the rear starts and gets quicky worse to the point that the whole car it shaking and you cannot go over 30 mph without it feeling like the wheels are coming off for a couple of miles then it just stops and it drives perfectly after that! I know it needs new rear bearings, I'm hoping this is the culprit. Any thoughts on what else I might be looking for?

 

P.s I'm not driving the car like this. It's been parked since this happened on my way home. 

[Tinonline]

Well it certainly appears to be a bearing problem: you might have lost a strip of balance weights?

[ambermarine]

Had a situation with my Mark 1 that vibration started at 60 but below that none ,turned out to be the trailing arm bushes and in the end we changed them all on the rear arms and the problem was solved.

They were actually shot and had been that way for some time.

[Newbie1]

Rear calipers seizing but loosen when driven?

[Matt1986]

Not sure. It's odd that it starts fine then comes on quickly and for a few minutes then is gone again. Always the same. I'll get the bearings done anyway and see if that sorts it out to start with. 

[steve2006]

While you are replacing the bearings it will be fairly easy to check all the suspension bushes but also check the diff mount bushes, transmission mount and prop shaft rubber donut.

[39buss]

I had a similar vibration on my GS 300 when it would drive perfectly OK to start off but then a vibration set in about 20mph and above. If I stopped and set off again it was sometimes OK.  I eventually found the trouble when I drove for a couple of miles and then touched all the wheels and the rear off side was much hotter than the rest which were considerably cooler.  The hand brake cable was seized and this in turn broke the casting which bolts to the back plate and the parking brake wasn't releasing hence the vibes. A new cable only available from Lexus (£60) and my regular garage fitted it and cleaned and checked both drum set ups.  No more vibes.  Wheel bearings make a noise generally all the time and especially when loaded going round corners.  losing a weight would set up vibes all the time and not now and then. All the info in the above postings is worth looking into.  Hope this helps. 

[Matt1986]

32 minutes ago, 39buss said:

I had a similar vibration on my GS 300 when it would drive perfectly OK to start off but then a vibration set in about 20mph and above. If I stopped and set off again it was sometimes OK.  I eventually found the trouble when I drove for a couple of miles and then touched all the wheels and the rear off side was much hotter than the rest which were considerably cooler.  The hand brake cable was seized and this in turn broke the casting which bolts to the back plate and the parking brake wasn't releasing hence the vibes. A new cable only available from Lexus (£60) and my regular garage fitted it and cleaned and checked both drum set ups.  No more vibes.  Wheel bearings make a noise generally all the time and especially when loaded going round corners.  losing a weight would set up vibes all the time and not now and then. All the info in the above postings is worth looking into.  Hope this helps. 

Thanks 39buss, I'll definitely have a look at that as my handbrake is pretty ineffective at the moment anyway. I've dropped how many miles I'm doing in the LS now so I'm hoping I can start to get ahead of these maintenance issues. 

[7149capricorn]

Sounds to me like dry cv joints on the half shafts.  Undo clip, insert cv grease and do up clip/replace with cable tie.  Worked for me with identical symptoms.

[malcolmdc]

Have had this identical problem twice on my Mk1 LS400, and on both occasions it was the rear brake caliper seizing, (first the right, and 12 months later the left) this made everything very hot, and alarming vibration fading when allowed to cool down. Calipers CAN be rebuilt if you, or your repairer, can get the overhaul kits (USA probably - watch the cylinder internal diameter!), but I replaced them on both occasions and complete cure resulted. I can tell you its a  bit of a pain getting new calipers cos there are different shape variations, but eBay came up with some from Germany, about 120 quid each time. Lots of photos ensured no mistakes.

[7149capricorn]

But, Matthew, you don't mention heat, it 'cures' itself after a couple of miles so the chance of it being bearings or sticking calipers is slim.  And why not go for the cheapest option first?

[CptYossarian]

This happened to me, and when a garage had it twice it was 'fixed'.

The parking brake mechanism had broken, and it was jamming on making the car shake violently and producing heat too.

My dad drove it and it didn't happen, but he must have given the parking brake lever some welly or got it to disengage. Unfortunately he applied it again when he parked up so when I got in and drove it the problem appeared again, as if by magic.

It confounded us for a while, and cost me £200 in the end to have done at my local friendly garage (£40ph labour).

[Matt1986]

Hi thanks everyone for your help with this, I'm leaning towards a brake issue as it only started after the car had stood for a week or so with the handbrake on. Seems to have stopped for now. I'll probably do what's been suggested as well.