Are All Ls400 Plagued By Vibrations ?

[90LS400Lexus]

My '93 also has a 50 mph vibration. Smooth as glass over 70.

After wheel balance, new tires, new brake rotors and pads, new tires (michelin)

still had the vibration. So I got smart and took my dial caliper to the axles, drive

shaft and wheels. Sure enough the right rear axle was out of round by 50

thousandths. Everything else was no more than 20 thous. After replacing the

axle the vibration was better, but still noticable and the axle is still 30-40 thous off.

Go figure! My point is that you may find the source of the vibration by simply

measuring and inspecting the drive train components. The ls400 has a complicated

drive train with two drive shafts, and independent rear suspension. Lots can go

wrong.

Thanks for the input. That will probably be my luck. I will have thousands spent on this before I get it repaired. I am going to try to get it checked this week.

[99lsguy]

Thanks for the input. That will probably be my luck. I will have thousands spent on this before I get it repaired. I am going to try to get it checked this week.

Just so we know, how many miles on the vehicle and what service intervals for ATF & Diff fluids..

Thanks

[90LS400Lexus]

Thanks for the input.  That will probably be my luck.  I will have thousands spent on this before I get it repaired.  I am going to try to get it checked this week.

Just so we know, how many miles on the vehicle and what service intervals for ATF & Diff fluids..

Thanks

It now has 226,800 miles. Not sure when the fliud was changed. It was a 1-owner car, but they did not keep all of the service record.

[SW03ES]

14 years and 230,000 miles, I'd be impressed the only thing wrong with it is a slight vibration! Thats well beyond the lifetime of other cars.

[jzz30]

it could be that drive shafts go out of balance or off center because of the bearing is worn and it doesnt spin true. did you guys know that the bolts that bolt the drive shafts to each ends have a specific weight?

[VBdenny]

I guess I'll count myself as lucky as my 90 with 135000 has no vibrations. It had a very slight vibration around 80mph when the tires were brand new, but as they wore in, it went away.

[90LS400Lexus]

I guess I'll count myself as lucky as my 90 with 135000 has no vibrations. It had a very slight vibration around 80mph when the tires were brand new, but as they wore in, it went away.

You are lucky. It seems very strange, but I do not recall my Lexus having this vibration when I first bought it a few months ago. Seems like it got worse when I had the OEM Toyota struts replaced on the rear. Is it possible that they did something wrong? I have no idea what however. I tried more of my own little tests and it seems like the vibration is worse under accelerations. I am going to try to take it this week to Lexus dealership or somewhere, as this vibration is very annoying.

Thanks again for the replies folks.

[SRK]

With a strut replacement I would think they did an alignment. Any charge on the bill for doing that?

A good alignment is a first step in removing and/or preventing vibrations. The pre-alignment check should reveal any bushing or suspension part wear, and the alignment insures all the angles are correct. These cars are fully, and easily adjustable in all angles on both the front and rear axles. Also if the alignment is off, it will tend to distort the tire carcass, eventually ruining the tire for high speed driving.

[SW03ES]

If they didn't do the alignment like they should have (after such a replacement you'd HAVE to do an alignment I would think) that could have caused the vibration.

That would also make sense why it gets worse under acceleration because weight is transfered to the rear...

[90LS400Lexus]

Thanks. No, they did not do an alignment and I was only charged for the strut replacement. They said that they did not have that capability. The car was aligned (4-wheel) about 10 months ago, but I guess that went down the tubes when the rear struts was replaced again when I bought it. I never took it to have it re-aligned, as I never got a definite answer as to whether or not I needed a rear wheel alignment. If this is causing the vibration, what could be going on to cause the vibration? It really seems to me as if it is the drivetrain causing it, but I could be very wrong. Hopefully this is the problem. I will try to take it this week to another mechanic that I take my cars to and let them check the alignment. That way I will know for sure. Thanks again.

[dboise]

For what it's worth, my '92 LS400 (200K miles) developed a vibration which was evident at 1000 revs and more pronounced at 2000 revs. Much worse when driving in gear, but still there in neutral. I changed plugs, wires, rotor/caps, but no help - no error codes from any of the engine/tranny diags. I eventually decided it must be tranny related and went to AAMCO of all places. They correctly diagnosed a cracked rear tranny mount and did a filter change flush/refill, replacing the fluid with Toyota T4 as required. Cost was $257.00, which is most reasonable. Smooth as silk now.

[elvis1962]

It sure seems like it. Seems like I see a lot of posts here about our LS400s having vibrations. It seems to be the #1 problem. I think one thing is that these cars are so smooth otherwise - that the slightest vibration can become intolerable. Are these cars just bad when it comes to vibrations? Perhaps I excpect to much from Lexus. Really do not hear much about it on other cars. I will not be satisified until I get rid of the vibration on my Lexus.

Vibrations can have a lot of sources, as you know and this may not be yours. My 1991 lexus LS-400 is now perfectly smooth but it took some work.

I had a vibration at about 60 on up. It felt exactly like two or more out of balance tires. It wasn't severe but enough to aggravate me every time I drove the car.

I changed tires and balanced for a year. There was some improvement but I kept getting the impression that even with a "perfect balance" I would still have some noticeable shake. This proved to be correct as I found out when I finally did fix this problem.

The solution was new lower ball joints. My 91 LS-400 had a design problem. The lower ball joints have an internal, nylon-type device made to keep grease in the right place to prolong ball-joint life. It was designed incorrectly and actually kept grease away from critical wearing surfaces. Newer ball joints have been improved to eliminate this flaw. Once replaced, the car runs perfectly smooth. There was enough play in the old ball joints to allow the front wheels to move slightly under the dynamic load of 60 mph and up. The end result was a vibration that felt the same as an out-of-balance tire. Just about any front-end component with excessive play can do this, but checking the ball joints is a good place to start. I don't believe the car is overly sensitive to tire balance now. I also changed the upper ball joints and lower control-arm bushings. These were changed later to tighten up the steering but the vibration was gone from the earlier fix. What an inprovement. The car rides and handles like new. It has 135,000 miles at this time.