brit_lex

Hi,

Right, here's my problem. My 92 LS400 presents the following symptoms when driving:
-entire front of car seems to oscillate up and down (as if shocks were worn) - not bad on very very smooth roads, but very noticeable on uneven surfaces. Especially noticeable at low speeds (below 40). Front of car feels tight but not planted to the road. Has been getting worse each month.
-Steering wheel has vibration through it particularly when braking since front of car seems to vibrate too when braking
-Clunking noise from front suspension very apparent when making left or right turns, particulary when turning the wheel full lock at low speed
-Engine vibration felt through brake pedal, shifter and steering wheel especially at idle (interestingly the vibration increased at idle the harder I pressed the brake pedal whilst in D?)
-Loud groaning (sounds like plastic rather than metal) sound from front suspension when driving cold car over speed humps
-Constant tyre wear on outside edges of front tyres (always happens since I bought the car)

To give you a background, this is what suspension items I have replaced since I have owned the car (last 55,000 miles/6 years - mostly stop start city driving).

All 4 wheels balanced and 4 wheel alignment done (this month)
New Dunlop tyres on front (this month)
New front upper control arms (last month)
New rear axle carrier bushes - polyurethane - (last month)
New Michelin tyres on rear (6 months ago)
New front brake discs and pads (6 months ago)
New shocks all round (6 months ago)
New strut bar, and strut bar cushions, drivers side front lower control arm (4 years ago)
New front springs (4.5 years ago)

All parts have been OEM.

I know that my rear upper control arms are very much worn as well.

After reading lots of posts on the website, I'm thinking that perhaps the front lower balljoints are really worn out which would be causing the front going up and down.
The engine mounts and transmission mount are likely to be split or worn out too given the mileage, but would that present itself as anything apart from vibration?

I'm planning on changing the front lower ball joints, engine and transmission mounts and rear upper control arms.

What do you guys think? Do tie rod ends need to be changed when replacing ball joints?

Total mileage is 168k right now. I do enjoy the car very much, and plan on keeping it a few more years.

Thanks so much guys.

Brit_Lex

P.S The car also exhibits vibration throughout the car (particularly on passenger side) from exactly 84mph (reminds me of the back to the future car!). A mechanic told me that the driveshaft prob needs replacing. Ideas?

SC400-V8

iTrader: (1)

When you speak of the control arms being worn, you mean the bushings right? I dont see how a piece of cast metal just "wears out."

persian451

why you got your springs changed from oem to oem, i dont know..

as far the vibration, judging by all the work you've done, its the transmission mount aka lower engine mount. it is 50 bucks for the part and 30 min installation, that is a potential DIY.

the clunking could be a number of things, sway bar bushings, strut mounts, lower ball joints, or bad upper ball joints.

but since you've changed all that stuff, it sounds like you need work on that mount i mentioned and sway bar bushings which should elminate the clunking while you steer, this is also a potential DIY with the bushings being about 15-20 a piece, and you only need 2.

as for the tie rods, if you hear clunking while you brake, then you know it could be those tie rods, I wouldnt worry about it too much. i'd do the tranny mount for now, and go step by step.

brit_lex

Thanks for the advice. It is very much appreciated.

Yes, the control arm bushings are very worn in the rear arms, but the arms are probably ok. To the best of my knowledge, the bushings are not made separately, you have to buy a new arm instead (About $100 each I think).

The reason the springs were changed from OEM to OEM, was that the dealer told me once that one of the front springs was cracked and had to be changed.

I thought there were 2 separate engine mounts and then a separate transmission mount?

Sway bar bushings are different from strut bar cushions? I thought the strut bar was the sway bar?

Another point to mention is that the bonnet of the car rises when accelerating and dives when the car brakes. Feels like I'm driving an American car from the 70s!

crazimofo

brit lex: What do you guys think? Do tie rod ends need to be changed when replacing ball joints?

I recommend you change your outer tierods, but thats my 2 cents. I did.

crazimofo

Sway bar bushings are different from strut bar cushions.
This is http://www.lexls.com/tutorials/suspe...enswaykit.html sway bar bushings.

This is a strut bar cushion I think. Am I right folks?


thanks Lexls for pics

hobaid

Hey Persian, how do you change the trans mount yourself??
Thanks