Help with vibration 92 ls400
08-21-09, 05:41 PM
#1
Driver School Candidate
Thread Starter
Help with vibration 92 ls400
hello,
I am hoping someone has had a similar problem or has come across one on the forum. I searched but no luck. I have a vibration that can be felt mostly above 60 mph, and it is felt in the body of the car, not the steering wheel. Felt mostly in my feet, seat, and I can also see the shifter moving slightly. What I have ruled out so far.....
-Not a wheel and tire problem. I replaced and ballanced my factory wheels and tires and performed an alignment. still there. Then I installed brand new staggered 18 inch wheels with bridgestone potenzas. Vibration did not change.
-Not a spring/strut problem. I installed brand new Ksport coilovers and performed an alignment with the new wheels/tires. Vibration still there, did not change.
-I then drove the vehicle on a lift with jack stands loading each rear suspension to simulate the weight of the car. No vibration from the trans, and the driveshaft looks to be ok. I do feel a slight vibration in the rear diff, with more vibration on the right rear hub.
I am thinking it could be an axle that is possible binding because of age and also my rear axles have leaked some greese from the clamps around the boots. I am just asking for people to start throwing out some suggestions in case I am missing something or if anyone knows any common problems with the ls400. The vibration definatly feels like it is from the rear, being that it is felt in the seat and floor. Vehicle has 178k. Thanks in advance.
I am hoping someone has had a similar problem or has come across one on the forum. I searched but no luck. I have a vibration that can be felt mostly above 60 mph, and it is felt in the body of the car, not the steering wheel. Felt mostly in my feet, seat, and I can also see the shifter moving slightly. What I have ruled out so far.....
-Not a wheel and tire problem. I replaced and ballanced my factory wheels and tires and performed an alignment. still there. Then I installed brand new staggered 18 inch wheels with bridgestone potenzas. Vibration did not change.
-Not a spring/strut problem. I installed brand new Ksport coilovers and performed an alignment with the new wheels/tires. Vibration still there, did not change.
-I then drove the vehicle on a lift with jack stands loading each rear suspension to simulate the weight of the car. No vibration from the trans, and the driveshaft looks to be ok. I do feel a slight vibration in the rear diff, with more vibration on the right rear hub.
I am thinking it could be an axle that is possible binding because of age and also my rear axles have leaked some greese from the clamps around the boots. I am just asking for people to start throwing out some suggestions in case I am missing something or if anyone knows any common problems with the ls400. The vibration definatly feels like it is from the rear, being that it is felt in the seat and floor. Vehicle has 178k. Thanks in advance.
08-21-09, 06:18 PM
#2
Long shot here...I had a vibration in my 90 LS400 when i got it in 2003 with 233K miles...I found a service bulletin for that year (not sure if it pertains to the 92) that recommended replacement of the transmission crossmember or something to that effect (about 60.00 at the time and not the tranny mount) I replaced it and voila no vibration..
08-21-09, 06:23 PM
#3
Tranny mount
Driveshaft bushing
Strut bars (front)
All of these can be causes for vibration. I have pretty much the same symptoms that you have, but narrowed mine down to the front strut bars. Visually they may look fine, but you have to take a pry bar and put some pressure on them in order to check the bushing on the front of the bar. Most likely the bushing is no good and needs to be replaced. IF you can locate a bushing for it, then you can change just that, but it is much easier to just replace the whole strut bar. Bushing is already pressed in for you. This is a fairly overlooked/common problem that should be addressed with the older LS's. I still need to do mine as well.
Tranny mount is another thing which will cause vibration, especially since you can see you shifter moving. Not hard to do, and is a fairly simple DIY (8 bolts).
Driveshaft bushing has also been known to produce some vibration, but is not as common as the other 2 I listed.
Did you have your tires balanced properly? I read that you did have it done. ALL Lexus cars are VERY SENSITIVE to balance issues so if shop didnt have the right equipment, could still be an issue. Need to locate a shop which uses a Hunter 9700, AKA Hunter Roadforce, machine. This seems to be a very good high speed balancer for our cars. You can use others, however make sure that their machines simulate roadforce at hi speeds.
You could have potential axle problems in the rear. How bad is the leak? Are the boots torn? Is there any noise coming from back there? You need to elaborate on what you spotted.
Just a few suggestons to look at.
Driveshaft bushing
Strut bars (front)
All of these can be causes for vibration. I have pretty much the same symptoms that you have, but narrowed mine down to the front strut bars. Visually they may look fine, but you have to take a pry bar and put some pressure on them in order to check the bushing on the front of the bar. Most likely the bushing is no good and needs to be replaced. IF you can locate a bushing for it, then you can change just that, but it is much easier to just replace the whole strut bar. Bushing is already pressed in for you. This is a fairly overlooked/common problem that should be addressed with the older LS's. I still need to do mine as well.
Tranny mount is another thing which will cause vibration, especially since you can see you shifter moving. Not hard to do, and is a fairly simple DIY (8 bolts).
Driveshaft bushing has also been known to produce some vibration, but is not as common as the other 2 I listed.
Did you have your tires balanced properly? I read that you did have it done. ALL Lexus cars are VERY SENSITIVE to balance issues so if shop didnt have the right equipment, could still be an issue. Need to locate a shop which uses a Hunter 9700, AKA Hunter Roadforce, machine. This seems to be a very good high speed balancer for our cars. You can use others, however make sure that their machines simulate roadforce at hi speeds.
You could have potential axle problems in the rear. How bad is the leak? Are the boots torn? Is there any noise coming from back there? You need to elaborate on what you spotted.
Just a few suggestons to look at.
08-22-09, 06:48 AM
#4
Lexus Test Driver
How many miles on the brakes/rotors?
A small amount of grease splashing from the rear axle boots is normal. If you've dropped the vehicle, you'll see this even more so since it changes the angle of the rear axles which allows more grease to seep out.
When you brake the vehicle, does the rear end feel unstable or like it wants to come around at all? Do you have any suspension noises?
Bradsters suggestion shouldn't apply to your 92. The part he's talking about is a one piece butterfly bracket that bolts onto each of the front cats and mounts to the bottom of the transmission with four bolts. The four bolt mounts have rubber bushings in them where it bolts to the tranny. Up until mid 91 I believe, there were two separate brackets, then it was changed to a single bracket to help minimize exhaust vibration.
A small amount of grease splashing from the rear axle boots is normal. If you've dropped the vehicle, you'll see this even more so since it changes the angle of the rear axles which allows more grease to seep out.
When you brake the vehicle, does the rear end feel unstable or like it wants to come around at all? Do you have any suspension noises?
Bradsters suggestion shouldn't apply to your 92. The part he's talking about is a one piece butterfly bracket that bolts onto each of the front cats and mounts to the bottom of the transmission with four bolts. The four bolt mounts have rubber bushings in them where it bolts to the tranny. Up until mid 91 I believe, there were two separate brackets, then it was changed to a single bracket to help minimize exhaust vibration.
)
08-22-09, 08:18 AM
#6
Rookie
Join Date: Aug 2009
Location: CA
Posts: 52
Likes: 0
Received 0 Likes
on
0 Posts
Check the rubber flex disc (sometimes called a guibo) at both ends of the driveshaft for cracks. This is an often neglected wear item that if it has never been replaced could be deteriorated. About $250 each at the dealer.
08-22-09, 09:03 AM
#7
Driver School Candidate
Thread Starter
thanks for the suggestions.
I ballanced my wheels/tires myself on a hunter ballancer and the roadforce was very low, more than acceptable.
The driveshaft couplers are not cracked and have no play, although i guess its possible with load, they could cause a vibration. I do have a slight clunk noises when turning a low speeds from the front end, I think it is the balljoints, but it is not that bad, only slight.
The weird thing is that it will get worse at times and then subside. If I go 90mph, it feels smooth.
I have no vibration under braking. My front pads/rotors have been replaced and are oem and have about 15k on them. I have never touched the rears, as they still have some pad left on them.
any other ideas?
I ballanced my wheels/tires myself on a hunter ballancer and the roadforce was very low, more than acceptable.
The driveshaft couplers are not cracked and have no play, although i guess its possible with load, they could cause a vibration. I do have a slight clunk noises when turning a low speeds from the front end, I think it is the balljoints, but it is not that bad, only slight.
The weird thing is that it will get worse at times and then subside. If I go 90mph, it feels smooth.
I have no vibration under braking. My front pads/rotors have been replaced and are oem and have about 15k on them. I have never touched the rears, as they still have some pad left on them.
any other ideas?
Trending Topics
08-22-09, 11:22 AM
#8
Lexus Test Driver
Since you think its coming from the rear, I'd get the rear up on two jackstands (let the differential drop down, no jack under it) and slowly spin each tire by hand and see if you feel anything grabbing at all during rotation. Then take both tires off and do the same just by spinning the rotors. See if something binds at all, even if its just a little. I'd check the rear caliper sliders and grease them up. I had a right rear and left front rotor problem before that was causing vibrations (91LS). They were OEM rotors as well with only 10k miles on them. Junk! I didn't have any vibration under braking either. I Replaced all 4 rotors and it went away. Also, make sure all the lug nuts are torqued the same, 76~80 ft lbs.
BTW, how long has the vibration been there?
BTW, how long has the vibration been there?
08-22-09, 02:17 PM
#9
Driver School Candidate
Thread Starter
the vibration has been there ever since I owned the car. just over 2 years now. It really hasnt gotten any worse. thanks for the help, I will check over some more stuff this week.
08-24-09, 07:05 PM
#11
Driver School Candidate
Thread Starter
Tranny mount
Driveshaft bushing
Strut bars (front)
All of these can be causes for vibration. I have pretty much the same symptoms that you have, but narrowed mine down to the front strut bars. Visually they may look fine, but you have to take a pry bar and put some pressure on them in order to check the bushing on the front of the bar. Most likely the bushing is no good and needs to be replaced. IF you can locate a bushing for it, then you can change just that, but it is much easier to just replace the whole strut bar. Bushing is already pressed in for you. This is a fairly overlooked/common problem that should be addressed with the older LS's. I still need to do mine as well.
Tranny mount is another thing which will cause vibration, especially since you can see you shifter moving. Not hard to do, and is a fairly simple DIY (8 bolts).
Driveshaft bushing has also been known to produce some vibration, but is not as common as the other 2 I listed.
Did you have your tires balanced properly? I read that you did have it done. ALL Lexus cars are VERY SENSITIVE to balance issues so if shop didnt have the right equipment, could still be an issue. Need to locate a shop which uses a Hunter 9700, AKA Hunter Roadforce, machine. This seems to be a very good high speed balancer for our cars. You can use others, however make sure that their machines simulate roadforce at hi speeds.
You could have potential axle problems in the rear. How bad is the leak? Are the boots torn? Is there any noise coming from back there? You need to elaborate on what you spotted.
Just a few suggestons to look at.
Driveshaft bushing
Strut bars (front)
All of these can be causes for vibration. I have pretty much the same symptoms that you have, but narrowed mine down to the front strut bars. Visually they may look fine, but you have to take a pry bar and put some pressure on them in order to check the bushing on the front of the bar. Most likely the bushing is no good and needs to be replaced. IF you can locate a bushing for it, then you can change just that, but it is much easier to just replace the whole strut bar. Bushing is already pressed in for you. This is a fairly overlooked/common problem that should be addressed with the older LS's. I still need to do mine as well.
Tranny mount is another thing which will cause vibration, especially since you can see you shifter moving. Not hard to do, and is a fairly simple DIY (8 bolts).
Driveshaft bushing has also been known to produce some vibration, but is not as common as the other 2 I listed.
Did you have your tires balanced properly? I read that you did have it done. ALL Lexus cars are VERY SENSITIVE to balance issues so if shop didnt have the right equipment, could still be an issue. Need to locate a shop which uses a Hunter 9700, AKA Hunter Roadforce, machine. This seems to be a very good high speed balancer for our cars. You can use others, however make sure that their machines simulate roadforce at hi speeds.
You could have potential axle problems in the rear. How bad is the leak? Are the boots torn? Is there any noise coming from back there? You need to elaborate on what you spotted.
Just a few suggestons to look at.
What do you mean by "strut bar" in the front. could you clarify? It doesnt have a strut tower bar. Thanks
08-24-09, 07:53 PM
#12
Lexus Test Driver
On your 1992 they're called strut bar cushions. It goes on the left end of part number 10 below. One each side. OEM Part Number: 48674-50030... You need to drop your undercarriage plastic engine shield to get a really good look at them from underneath the front of the vehicle.
12-19-09, 09:49 PM
#13
Driver School Candidate
Join Date: Jul 2003
Location: Alabama
Posts: 29
Likes: 0
Received 0 Likes
on
0 Posts
Yes! What is it? Ive been dealing with this issue for 2 years! The whole *** end feels like it takes a step to the right every time the brakes are applied. I accidentally found this while looking for what that plastic engine shield under the car is actually called. What should I do a search for to find the answer?
12-19-09, 11:49 PM
#14
Lexus Test Driver
It's the carrier arm bushings (ADUS 505 is the aftermarket poly replacement part) that are at the base of the knuckle which the right side of part #9 (strut rod) attaches to. The bushing shown in the pic that goes into the left side of the #9 strut rod and bolts up to the rear subframe should be replaced at the same time. That bushing is also available as a poly aftermarket but I can't remember the aftermarket part number for it.
