94 LS400 Vibration Between 30-35mph

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Oct 18, 2020 | 11:25 AM
  #1  
Hello all, I have a vibration between 28-35mph that is felt ONLY in the steering wheel. As soon as I hit above 35mph it goes away. Engine speed does not affect the vibration and putting it in neutral does not affect it. Basically no matter what as long as the car is rolling from 28-35mph the steering wheel is vibrating.

I replaced all 4 tires today, no wheels are bent, and the wheel bearings and hubs were replaced last week. The whole front end has been refreshed with everything OEM besides new brake calipers in the past 6 months.

This issue seemed to pop up randomly and not after any work was done. Idk what to think at this point.. Sticking brake caliper?

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Oct 19, 2020 | 12:22 PM
  #2  
since the newest items were tires, make sure they were balanced properly and lug nuts seated correctly.

lastly i suspect the transmission mount is toast, which is very common at high miles and old age! it's another source of vehicle speed related vibrations - and it's easy to replace and relatively cheap to buy!
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Oct 19, 2020 | 12:59 PM
  #3  
As Timmy mentions. May also rotate the tires to see if the vibration changes to the rear.
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Oct 19, 2020 | 04:34 PM
  #4  
Thank you for the replies!

I believe I have narrowed it down to out of round rotors. I cleaned the caliper slide pins and regreased them, along with pushing in the caliper pistons to check for any binding. No issues with Calipers.
So I hand tightened all 5 lug nuts on each rotor to the hub and spun them by hand, The left side is very "wobbly" when watching it spin with the naked eye. Also when I brake at the mentioned speed the vibration is affected/changes.

The Issue was present before I got new tires so I don't believe they are at fault but I will check again if need be.
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Oct 22, 2020 | 11:00 AM
  #5  
Quote: Thank you for the replies!

I believe I have narrowed it down to out of round rotors. I cleaned the caliper slide pins and regreased them, along with pushing in the caliper pistons to check for any binding. No issues with Calipers.
So I hand tightened all 5 lug nuts on each rotor to the hub and spun them by hand, The left side is very "wobbly" when watching it spin with the naked eye. Also when I brake at the mentioned speed the vibration is affected/changes.

The Issue was present before I got new tires so I don't believe they are at fault but I will check again if need be.
As Timmy said, i'd still check the transmission mount, as that is about the speed where you will get vibration at.
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Oct 22, 2020 | 12:06 PM
  #6  
Quote: As Timmy said, i'd still check the transmission mount, as that is about the speed where you will get vibration at.
Both engine and transmission mounts changed less than 5k ago.

I am leaning towards a possible bent wheel now. I will rotate wheels from front to back and see if it changes anything.
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Oct 22, 2020 | 06:44 PM
  #7  
Quote: Hello all, I have a vibration between 28-35mph that is felt ONLY in the steering wheel. As soon as I hit above 35mph it goes away. Engine speed does not affect the vibration and putting it in neutral does not affect it. Basically no matter what as long as the car is rolling from 28-35mph the steering wheel is vibrating.

I replaced all 4 tires today, no wheels are bent, and the wheel bearings and hubs were replaced last week. The whole front end has been refreshed with everything OEM besides new brake calipers in the past 6 months.

This issue seemed to pop up randomly and not after any work was done. Idk what to think at this point.. Sticking brake caliper?

Let's try an advanced check.
a) jack up a wheel and check rim edges for both side-to-side runout and possible out-of-round. Pull wheel off. Pull out a dial indicator and check the disks for run-out on the wheel mounting surface. Even beautifully balanced wheels will add to the problem if the rotors are slightly off true where they mate up with the hubs. You can even check the runout of the hub flange should you remove the disks. OEM disks have a whole bunch of mounting screw holes so you can go find the perfect "0" runout spot ...
Colin
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Oct 23, 2020 | 06:22 AM
  #8  
Quote: Let's try an advanced check.
a) jack up a wheel and check rim edges for both side-to-side runout and possible out-of-round. Pull wheel off. Pull out a dial indicator and check the disks for run-out on the wheel mounting surface. Even beautifully balanced wheels will add to the problem if the rotors are slightly off true where they mate up with the hubs. You can even check the runout of the hub flange should you remove the disks. OEM disks have a whole bunch of mounting screw holes so you can go find the perfect "0" runout spot ...
Colin
I will perform this as a last result if tire rotation does not provide relief.
Wheel hubs/bearings and brake rotors are new. Also the exact same vibration was present before I replaced them and with the old tires
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Oct 23, 2020 | 11:05 AM
  #9  
The candidates for vibrations like this are wheels (brakes, tires, rims), motor\trans mounts and ball joints. Bushings are less likely to cause weird vibrations according to a friend of mine who works for FCA (he was on the Dodge Viper team).

When you say you replaced the entire front-end, I presume that includes ball joints? My lower ball joints on the front were shot and was sending a clunk\vibration through to the steering wheel causing it to physically move.
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Oct 23, 2020 | 12:25 PM
  #10  
Quote: The candidates for vibrations like this are wheels (brakes, tires, rims), motor\trans mounts and ball joints. Bushings are less likely to cause weird vibrations according to a friend of mine who works for FCA (he was on the Dodge Viper team).

When you say you replaced the entire front-end, I presume that includes ball joints? My lower ball joints on the front were shot and was sending a clunk\vibration through to the steering wheel causing it to physically move.
Yes ball joints included. Tires/wheels will be the first thing to try this weekend
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Oct 24, 2020 | 07:32 PM
  #11  
Quote: The candidates for vibrations like this are wheels (brakes, tires, rims), motor\trans mounts and ball joints. Bushings are less likely to cause weird vibrations according to a friend of mine who works for FCA (he was on the Dodge Viper team).

When you say you replaced the entire front-end, I presume that includes ball joints? My lower ball joints on the front were shot and was sending a clunk\vibration through to the steering wheel causing it to physically move.
Ok I have rotated tires and the vibration is the same. I took it for a test drive and noticed a hollow noise at the front drivers tire when hitting bumps and also have experienced the "driving on marbles effect" doing a U-turn to the left.

While replacing the control arm bushings a few weeks ago, I left the ball joints attached to the control arms. The drivers side ball joint was much easier to move by hand compared to the passenger side, it felt very loose but I assumed it was just normal play since they both have less than 5k miles on them... Now I think that since my drivers side wheel bearing was horribly worn compared to the passenger side, I may have caused the new ball joint to prematurely fail before replacing the wheel bearings.

Are the OEM ball joints known to be weak on these cars?

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Oct 25, 2020 | 09:27 AM
  #12  
Also when getting new tires they checked the alignment. The toe on the drivers side was a hair away from being out of spec whereas the passenger side was nearly perfect.

Last alignment before that was less than a month ago...

So I will replace the lower balljoints and go from there. I assume I have prematurely worn it out by driving with a bad wheel bearing for a few thousand miles.
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Oct 25, 2020 | 01:26 PM
  #13  
Quote: Are the OEM ball joints known to be weak on these cars?
Of all the suspension components, if I had to pick the two weakest\most commonly replaced ones, they would be the front strut bars and the front lower ball joints.

My original ball joints needed replacing about a year ago. They visually inspected fine, the boot wasn't leaking and there wasn't slop in the wheel while it was in the air. When my mechanic pulled them off he said he would have put them back on the car, visually they looked fine. Here were my symptoms:

Excessive tram-lining in the grooves in the road, especially on the highway.

Clunk on bumps that moved the steering column and the steering wheel.

Random clunks\pops\noise from the front end, but this was rather subtle.

Excessive body roll during low speed turns, there was a significant reduction when I replaced them.

General vagueness in steering that was really most noticeable after they were replaced, everything tightened up.

I don't remember the car washing out while doing a U-turn.

Replacing mine made a huge difference. HOWEVER! I would say it would be rather unusual for an OEM part to fail so quickly.
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Oct 31, 2020 | 10:17 AM
  #14  
Okay after further inspection the Inner tie rod on the passenger side is bad
I replaced the rack back in May with a reman unit from cardone that came with inner tie rods already installed. I think it is safe to say they were not OEM tie rods! Now going to order both inner rods from Lexus and move forward

Thank you all for your input!
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Oct 31, 2020 | 05:32 PM
  #15  
Quote: Okay after further inspection the Inner tie rod on the passenger side is bad
I replaced the rack back in May with a reman unit from cardone that came with inner tie rods already installed. I think it is safe to say they were not OEM tie rods! Now going to order both inner rods from Lexus and move forward

Thank you all for your input!
Whaaat???? After market suspension parts that are total garbage that didnt last 6 months?????? Well knock me over with a feather (which any more is getting that much closer to reality,LOL!)
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