Vibration In The Whole Car

[94Celsior]

when i slow down from 69-60 mph my whole car vibrates. my sterring wheel, my shifter, the whole thing. it annoys me because i want the ride to be smooth. i had my rotors checked out and they said thy wernt warped. have any advice let me know

-alex

[UCF3]

COuple of things come to mine. One Tire pressure, and Alignment. Check your tire pressure; all should be 30spi or 32psi.

Kind of curious if you're braking from 69-60mph?

[90LS400Lexus]

What is the year and mileage of the car?

[VMF]

if its only when you press the brake pedal it might be that your front rotors are bent. most probably it is the cause and also check the balance of your front tires. if they are okey then have your front rotors resurfaced and only after this do the alignment since its a complicated job on a lexus

[VBdenny]

you may wish to check your universal joints on your driveshaft, the vibration you are experiencing is a common symtom. If it is going bad, the vibration will continue to grow worse. Although I've never heard of anyone having this problem on a LS, it is a possibilty worth checking.

[99lsguy]

I think VBDenny is on the right track.

YEs, let us know if you are BRAKING and this is happening; or if it happens once you let foot off the gas and you COAST down to slower speed.

The flange bolts on the driveshaft & each side of differential are usually re-torqued every 5K.

How about your tire wear? check inside and out.....front and rear for discrepencies.

[VBdenny]

Thanks Agent 99. I didn't know about the 5k retorque thing, something which probalbly nobody ever does. Might be something incredibly simple.

[99lsguy]

ALL THESE SPECS ARE FROM 99 MANUAL BUT SHOULD BE IN THE BALLPARK:

Those flange bolts that tie into the diff. case from the L/R axles are :

10mm hex bolts - torque is 61 ft. lbs. Six bolts each side

The main driveshaft (Lexus calls it the PROPELLER SHAFT) has Three bolts attached @ transmission case & 3 @ Diffy. case. Torque is 58 ft. lbs each.

One last item with could vibrate; the middle section of the propeller shaft HAS A CENTER SUPPORT BEARING and is mounted by two bolts @ 27 ft. lbs each. Check those too as they have adjusting washers to keep proper angles of the propeller shaft assembly.

The TROUBLE SHOOTING SYMPTOMS FOR VIBRATION ARE:

1 - Transmission extension housing rear bushing - WORN

2 - Flexible Couplings (to tranny & diffy) - WORN

3 - Sleeve yoke spline - STUCK

4 - Propeller shaft runout

5 - Propeller shaft imbalance

Let us know....

99

(VB - I lilke that Agent 99 bit :D )

[90LS400Lexus]

I have noticed that my 90 LS400 has a slight vibration when I reach 50 MPH- up to about 60 MPH. I can barely feel it in the steering wheel. Most people probably would not even notice it. I have just been assuming it is the tires, but they are brand new- but I guess it is still possible that one is out of balance- or I guess it could be some type of mount. At speeds around 65-80- it is as smooth as silk. Just that 50-60 mph range. My car is 14 years old however, with 226K, I really should not expect it to be perfect- which is really bad, because since it is a Lexus- I guess I want it to be that way- despite the age & mileage.

One thing I noticed- when I first start the car in the morning- when it is at fast idle- around 1700 rpms- it will have a vibration every 2 seconds- like something is out of round. Perhaps my motor mount is getting worn- which may be the vibration at 50-60 mph speeds?

[SKperformance]

i would agree with the driveshaft play in the bushings or pins.

Also you might want your suspension checked for excessive play in the rear

the minimal amount of pull of engine braking can cause the suspension to add a new angle to the driveshaft and cause an annoying unharmonic balance of the shaft.

Try going to normal speed and repeating the problem in drive and then in neutral to see if it changes.

[jschunke]

Speaking of vibration. My 93 LS also has a vibration at 50-65 MPH. Then

smooth over 70. Took it to the dealer and they had no clue. Taking matters

in my own hands I found some run-out on the right rear drive axle (40-50

thousandths). After replacing the axle the vibration was mitigated a little, and

there was still a good amount of run-out (30 th). Now have brand new tires and

alignment but the vibration is still detectable. So much so that I gave the car

to dad. He doesn't really notice it, but drove me nuts. There must

be something wacky with the differential flange?

[VMF]

once again, this spees specific vibration is 90% due to the unbalanced wheels. i had this problem for a while and i checked everzthing and it turned out to be unbalanced wheels. its a 5$ job for a wheel and u need to check only front 2 wheels. i think its worth trying to eliminate this cause b4 going to deep. dont repeat my mistake. i alreacy changed brake rotors, lower arms and a rim with a tire!

[mjrav]

I just went through a similar problem with my LS400 200,000 miles.

I turned the two front rotors twice on my lathe. Each time the problem went away for awhile then came back. Nasty shake at off ramp speeds mostly in the steering wheel and brake pedal. (While braking)

I purchased one new rotor for worst offending RF wheel and problem is gone.

I think it's a GLAZING thing causing uneven friction. At certain speeds the brake lines telegraph these pulses through the system agravating the problem. That's why you feel it in the pedal so much.