92 Ls400 Vibration

[elvis]

>>Their goal was a world-class smooth, quiet car which they succeeded at.

Well, when it's not vibrating I'd say you're right. When it is though, it's pretty disappointing. Difficult to rectify too.

I agree 100%.

The rebuilt driveshaft finally came. I will send it back. Although advertised on-line to fit a 1991 Lexus LS-400, the front drive shaft section was a different design and 2 1/2 inches shorter in the spline than mine. Not enough spline length to adequately join it to the other section and no locking nut like mine has to secure the spline to the other section. I don't know what car it came off of. The biggest disappointment was that it was not rebuilt as advertised. Under the fresh flat black paint was a rusted, apparently used U-Joint and center bearing. This for almost $500. I have never seen a rebuilt part come in in this shape. It was obviously pieced together from parts, somewhat cleaned and sprayed black. One other detail, it was phased wrong in the yokes and could not be corrected due to a keyed spline. Ordered one from Lexus today (ouch!).

Elvis

[mwc0610]

ELVIS and Other, I finally had a breakthrough with my vibration issue. You gotta read this and you're going to flip if this works for you. MY CAR DRIVES LIKE A BRAND NEW ONE NOW... I COULDN'T BE HAPPIER. Here's what I did. I took my car to Lexus and ask them to diagnose the problem. They said I needed to replace all my mounts, even after 3 others told me that I didn't and by looking at the Transmission mount it looked perfect, BUT BUT BUT... That was the problem. Get this. I went and purchased the transmission mount for $42 from the dealer. It took me a total of $45 minutes to replace it and low and behold it was the culprit. Here's what's happen. Even though the mount looked perfect, it was collapse just enough for the top place to sit on top the bottom place, causing the vibration. The new mount has clearance between the top and bottom but you can't hardly see it. The mount looks perfect from the eye but it's the culprit. I was so freaking happy I took my car for 2 rides last night and had the wife get in the car to brag to her. I've been driving her crazy for the past 10 months. My car drives like new. Let me know if this fixes your problem. I sure hope it does. I'm not touching the other mounts right now.

>>Their goal was a world-class smooth, quiet car which they succeeded at.

Well, when it's not vibrating I'd say you're right. When it is though, it's pretty disappointing. Difficult to rectify too.

I agree 100%.

The rebuilt driveshaft finally came. I will send it back. Although advertised on-line to fit a 1991 Lexus LS-400, the front drive shaft section was a different design and 2 1/2 inches shorter in the spline than mine. Not enough spline length to adequately join it to the other section and no locking nut like mine has to secure the spline to the other section. I don't know what car it came off of. The biggest disappointment was that it was not rebuilt as advertised. Under the fresh flat black paint was a rusted, apparently used U-Joint and center bearing. This for almost $500. I have never seen a rebuilt part come in in this shape. It was obviously pieced together from parts, somewhat cleaned and sprayed black. One other detail, it was phased wrong in the yokes and could not be corrected due to a keyed spline. Ordered one from Lexus today (ouch!).

Elvis

[mwc0610]

Sorry for the excitement and misprints below. I spent 45 minutes to fix the problem. The problem was the top metal plate of the transmission mount was sitting on top the bottom plate, causing the vibration, but the two rubber supports looked perfect to me and 3 other mechanics. Gosh, i sure hope this fixes your problem. Jack up your car, and hold it up with stands and then take your jack and slightly support the tranny, don't rise it, just support. Remove 4 nuts on the transmission mount, then remove 4 bolts on the plate that the mount connect to. This will leave the mount connected to the tranny. Remove the 4 bolts holding mount to transmission mount, and then install new one.

Good Luck guys

ELVIS and Other, I finally had a breakthrough with my vibration issue. You gotta read this and you're going to flip if this works for you. MY CAR DRIVES LIKE A BRAND NEW ONE NOW... I COULDN'T BE HAPPIER. Here's what I did. I took my car to Lexus and ask them to diagnose the problem. They said I needed to replace all my mounts, even after 3 others told me that I didn't and by looking at the Transmission mount it looked perfect, BUT BUT BUT... That was the problem. Get this. I went and purchased the transmission mount for $42 from the dealer. It took me a total of $45 minutes to replace it and low and behold it was the culprit. Here's what's happen. Even though the mount looked perfect, it was collapse just enough for the top place to sit on top the bottom place, causing the vibration. The new mount has clearance between the top and bottom but you can't hardly see it. The mount looks perfect from the eye but it's the culprit. I was so freaking happy I took my car for 2 rides last night and had the wife get in the car to brag to her. I've been driving her crazy for the past 10 months. My car drives like new. Let me know if this fixes your problem. I sure hope it does. I'm not touching the other mounts right now.

>>Their goal was a world-class smooth, quiet car which they succeeded at.

Well, when it's not vibrating I'd say you're right. When it is though, it's pretty disappointing. Difficult to rectify too.

I agree 100%.

The rebuilt driveshaft finally came. I will send it back. Although advertised on-line to fit a 1991 Lexus LS-400, the front drive shaft section was a different design and 2 1/2 inches shorter in the spline than mine. Not enough spline length to adequately join it to the other section and no locking nut like mine has to secure the spline to the other section. I don't know what car it came off of. The biggest disappointment was that it was not rebuilt as advertised. Under the fresh flat black paint was a rusted, apparently used U-Joint and center bearing. This for almost $500. I have never seen a rebuilt part come in in this shape. It was obviously pieced together from parts, somewhat cleaned and sprayed black. One other detail, it was phased wrong in the yokes and could not be corrected due to a keyed spline. Ordered one from Lexus today (ouch!).

Elvis

[nc211]

well, if you're this pleased with the tranny mount, just wait until you do the two motor mounts! Probably one of the best replacements I ever did on mine, really made it nice and quiet, smooth, and solid feeling. And the $15 rack grommets, which were easy as pie to do! Which insulated any vibration from the engine from the steering wheel.

[mwc0610]

So NC, how hard was it to change out the left and right motor mounts? Damn, those things are expensive - $112 each. Any tips on how you do this. I figure just have to jack up the engine slightly. I just want to make sure I don't hurt/bend anything else in the process. Also can you tell me where the rack grommets are located and how easy they are to replace? Heck, I'm willing to spend money to have my baby back riding like brand new.

well, if you're this pleased with the tranny mount, just wait until you do the two motor mounts! Probably one of the best replacements I ever did on mine, really made it nice and quiet, smooth, and solid feeling. And the $15 rack grommets, which were easy as pie to do! Which insulated any vibration from the engine from the steering wheel.

[nc211]

$112? You buying your parts straight from the dealer? Go to www.parts.com and drill down to the Lexus 95' LS400. They're $83 each, need two of them, labeled "front mounts". The rear mount is the tranny mount, $29 bucks. The driver's side is a mother to change, the passenger side I hear is not so bad. I bought my mounts and took the car to the exxon station garage by my old office to have them put in. Cost about $150 for both to be installed, and the mechanic nearly broke his knuckles on the driver's side.

Look under the car for the steering rack tube. See the two U clamps on the ends of the tube? Those clamps hold the rubber grommets in place, which are nothing more than just round pieces of rubber, that are cut in the middle for installation. Simply undo the bolts to those U clamps, wiggle out the old, wiggle in the new, and reclamp. Simple as pie! They're #2 in the attached picture, cost $15 a piece on parts.com. You can find them under the Steering gear & linkage section / gear assy/ "insulator".

[elvis]

Sorry for the excitement and misprints below. I spent 45 minutes to fix the problem. The problem was the top metal plate of the transmission mount was sitting on top the bottom plate, causing the vibration, but the two rubber supports looked perfect to me and 3 other mechanics. Gosh, i sure hope this fixes your problem. Jack up your car, and hold it up with stands and then take your jack and slightly support the tranny, don't rise it, just support. Remove 4 nuts on the transmission mount, then remove 4 bolts on the plate that the mount connect to. This will leave the mount connected to the tranny. Remove the 4 bolts holding mount to transmission mount, and then install new one.

Good Luck guys

ELVIS and Other, I finally had a breakthrough with my vibration issue. You gotta read this and you're going to flip if this works for you. MY CAR DRIVES LIKE A BRAND NEW ONE NOW... I COULDN'T BE HAPPIER. Here's what I did. I took my car to Lexus and ask them to diagnose the problem. They said I needed to replace all my mounts, even after 3 others told me that I didn't and by looking at the Transmission mount it looked perfect, BUT BUT BUT... That was the problem. Get this. I went and purchased the transmission mount for $42 from the dealer. It took me a total of $45 minutes to replace it and low and behold it was the culprit. Here's what's happen. Even though the mount looked perfect, it was collapse just enough for the top place to sit on top the bottom place, causing the vibration. The new mount has clearance between the top and bottom but you can't hardly see it. The mount looks perfect from the eye but it's the culprit. I was so freaking happy I took my car for 2 rides last night and had the wife get in the car to brag to her. I've been driving her crazy for the past 10 months. My car drives like new. Let me know if this fixes your problem. I sure hope it does. I'm not touching the other mounts right now.

This is Elvis,

The rebuilt driveshaft finally came. I will send it back. Although advertised on-line to fit a 1991 Lexus LS-400, the front drive shaft section was a different design and 2 1/2 inches shorter in the spline than mine. Not enough spline length to adequately join it to the other section and no locking nut like mine has to secure the spline to the other section. I don't know what car it came off of. The biggest disappointment was that it was not rebuilt as advertised. Under the fresh flat black paint was a rusted, apparently used U-Joint and center bearing. This for almost $500. I have never seen a rebuilt part come in in this shape. It was obviously pieced together from parts, somewhat cleaned and sprayed black. One other detail, it was phased wrong in the yokes and could not be corrected due to a keyed spline. It may have been doctored by another customer and returned to the seller who sent it to me without knowing it. It did look like it was opened previously. I ordered one from Lexus today (ouch!).

Elvis

Update (finally). The car is fixed!

Here’s brief summary of the work done on my 1991 Lexus LS400 with 175K miles on it. A lot of work was to fix vibration problems but work was also done to fix other problems brought on by age and miles.

The biggest problem was a vibration in the floor and steering wheel at 38-45 MPH. The got worse over time (1-2 years). The cause was a bad center U-joint in the front driveshaft. The U-joint was nowhere to be found, nor was a correct-fitting rebuilt drive shaft available. I painfully paid for a new driveshaft from Lexus. It was an excellent unit with a new center bearing and end couplings included. Lexus list was $928.

The next biggest problem was a sagging rear transmission mount. Not costly to fix and easy to change. It removed a large amount of engine and wheel noise. The difference was remarkable and unexpected. THANKS “mwc0610” FOR POINTING THIS FIX OUT. It was difficult to see, as stated. I didn't notice it on the bench but could see it when it had the trans weight on it. When the trans mount sags, the center gap closes and its metal to metal except for a small rubber cushion in between. You won’t see it unless you know where to look. Even then its hard to spot.

These two fixes brought the car back to running smooth and quiet.

As maintenance items, I also changed:

Tires – went to Michelin Primacy MXV4. Seems like a well-handling, smooth tire. Maybe a little stiff over certain bumps but I did put in urethane bushings.

Power steering pump idle-up valve - leaking internal valve causing white smoke on startup.

Tie-rod ends - loose enough to cause wandering. Not real bad but steering is precise now.

Front lower control arm bushings – also helped steering.

Brake pads and rotors turned – Replaced with Akebono pads. Very nice. One longer stop when cold, then excellent, no dust.

Rear trailing arm bushings – These were very bad. Helped handling. Eliminated pull to the right and shudder when stopping. Brake job reduced shudder also.

New water pump and timing belt (second set on this car).

New plug wires.

It’s a much better car and a pleasure to drive. The fuel injection unit is on the bench now. It has a huge amount of carbon in the intake plenum and behind the throttle body. This despite always running well and using good gas.

Has anyone had any luck in removing the EGR system or blocking the passage?

Elvis

Good Trans Mount

Bad Trans Mount

[eddielasvegas]

Elvis: Thanks for the info and the good and bad tranny mount pictures.

Eddie

[90LS400Lexus]

Well, interesting thread. As mentioned in another post, a friend of mine has a 1993 LS400 with a very similiar vibration as does my 1991 LS400 w/208K. <_<

Mine is between mainly 35-55 mph and mostly felt through the steering wheel. Its a vibration that provides a slight rumbling sensation in my ears. Its also like something is out of balance, because it seems to come and go every second or so. My old 90' LS400 did this as well and I took it to the dealer to have it checked... the Lexus dealer said it was the tires... I had new rear struts installed at a small repair shop and they did not do an alignment and it "cupped" my tires. I never really knew if that was indeed the problem because I sold the car right after.

My current LS400 has had the same tires since 2003 and it has not been driven much over the past year... it sat in a garage in Georgia, driven less than 1000 miles in 14 months. I was wondering if perhaps the tires had developed some "flat" spots on them from setting and being old tires. I know that since they are nearly 5 years old that I should change them first to see if thats my problem... on the other thread, someone recommended that to me. I just hate to keep buying part after part to find out what it is. I was thinking either tires, engine mounts, transmission mount, u-joints, wheel bearings, etc... or all of the above. :( Vibrations drive me nuts... maybe one day I will be able to track down the problem, as well as my friend on her LS400.

[elvis]

90LS400Lexus,

I would definitely check the easy things first. The tires could have taken a set but that should go away if the tires are brought up to temperature a few times for, say, 30 minutes at 50 or above.

The trans mount is most likely sagged at 200K miles. That can be looked at easily if the car is on a lift. Its a simple 15 minute job once its on the lift. With that mileage, I would bring one with me and have the mechanic just install it. I actually bought mine new on eBay for under $50. It was a new Lexus OEM part. I think the Lexus dealer price is around $80. When they sag, a lot of engine noise and vibration gets transmitted to the steering wheel and floorboard. That's probably not all your vibration but it will make a good improvement if it is sagged. Note that many good mechanics may not know what a bad Lexus trans mount looks like but pictures are earlier on this post.

Bad front lower or upper ball joints can cause a shake/vibration. A qualified mechanic can check those easily.

Last would be the drive shaft and center U-joint. There is also a center bearing. This gets expensive and tougher to diagnose. I would keep it in mind because of the mileage and the fact that you have symptoms which could point to it: Steering wheel vibrations starting at a lower speed, drumming or humming sound, and 200k miles on the car. I could not tell mine was bad until I had the drive shaft out and the two sections separated. Then I could feel a notch in the U joint as I moved it. Its a pain to pull it just to check the u-joint. I could not locate just a U-joint which is usually a $20 part. Lexus sells only the entire assembly. The drive shaft was $928 from Lexus but it did cure my particular problem. There are rebuilt drive shafts advertised but I couldn't actually find one in stock to fit a 91. You would have to find a trusted mechanic willing to work with you on the diagnosis and not want to replace it unless it was actually bad.

Elvis

[90LS400Lexus]

Thanks for that info! Well, I went ahead and made an appointment @ my local Lexus dealer to have my car checked on Tuesday. He said they would check it out for $35.00, so I figure it would be worth the $35, rather then me to replace this and that. He said it could very well be the transmission mount. He said that the engine mounts were liquid filled and he had personally never heard of many of those just going bad and he had been at the dealer service since they opened in 1990. He said they mainly only need replacing if the car was in an accident. So I have no idea about that.

I noticed that today when I was setting at idle in a drive thru, I could still feel the vibration and it was actually causing something near the "A-pillar" to make a buzzing noise... I think it was the window. Another thing I have noticed is that if the engine is still cool and it is in 4th gear and I am accelerating @ 35 mph, I hear a whining/whirring noise that goes away when the lock-up kicks off. When the engine is fully warmed, it does not do it.

Something I can definitely not put up with. I will report what I find out.

90LS400Lexus,

I would definitely check the easy things first. The tires could have taken a set but that should go away if the tires are brought up to temperature a few times for, say, 30 minutes at 50 or above.

The trans mount is most likely sagged at 200K miles. That can be looked at easily if the car is on a lift. Its a simple 15 minute job once its on the lift. With that mileage, I would bring one with me and have the mechanic just install it. I actually bought mine new on eBay for under $50. It was a new Lexus OEM part. I think the Lexus dealer price is around $80. When they sag, a lot of engine noise and vibration gets transmitted to the steering wheel and floorboard. That's probably not all your vibration but it will make a good improvement if it is sagged. Note that many good mechanics may not know what a bad Lexus trans mount looks like but pictures are earlier on this post.

Bad front lower or upper ball joints can cause a shake/vibration. A qualified mechanic can check those easily.

Last would be the drive shaft and center U-joint. There is also a center bearing. This gets expensive and tougher to diagnose. I would keep it in mind because of the mileage and the fact that you have symptoms which could point to it: Steering wheel vibrations starting at a lower speed, drumming or humming sound, and 200k miles on the car. I could not tell mine was bad until I had the drive shaft out and the two sections separated. Then I could feel a notch in the U joint as I moved it. Its a pain to pull it just to check the u-joint. I could not locate just a U-joint which is usually a $20 part. Lexus sells only the entire assembly. The drive shaft was $928 from Lexus but it did cure my particular problem. There are rebuilt drive shafts advertised but I couldn't actually find one in stock to fit a 91. You would have to find a trusted mechanic willing to work with you on the diagnosis and not want to replace it unless it was actually bad.

Elvis

[elvis]

You're welcome. Let us know what they find.

Elvis

[90LS400Lexus]

Thanks... I sure will. I am hoping it is something simple like the tranny mount, or tires. I would cry if it was the driveshaft! :cries: If it is the driveshaft, I would have to park the car and sell it eventually, because I cannot afford a $1000 part. :(

[W201 sweden]

Very interesting reading. I have a -95 LS 400 with the problems discussed here, and I am considering a full rebuild of mounts, bushings and drive shaft (propeller shaft). However, spare part prices for the LS are INSANE in Sweden.

Drive shaft, new - not rebuilt, is over $3000!

Engine mounts are $300/each.

Rear engine/tranny mount is a "mere" $120.

After that I was too shocked to ask for prices for the chassi parts. :

Even if I do ALL the work myself, the parts alone would be a hefty $4500 or so.

There are virtually no "non genuine" / "after market" parts for the -95 LS, which is rare as a Ferrari here. It has to be the Lexus dealer or internet. I guess I will try to order parts from US, but shipping is a problem...

Or perhaps I will do like nc211 -sell it-, but do it BEFORE fixing all the issues. But I DO like the car... :cries:

/Alexander

[nc211]

Very interesting reading. I have a -95 LS 400 with the problems discussed here, and I am considering a full rebuild of mounts, bushings and drive shaft (propeller shaft). However, spare part prices for the LS are INSANE in Sweden.

Drive shaft, new - not rebuilt, is over $3000!

Engine mounts are $300/each.

Rear engine/tranny mount is a "mere" $120.

After that I was too shocked to ask for prices for the chassi parts. :

Even if I do ALL the work myself, the parts alone would be a hefty $4500 or so.

There are virtually no "non genuine" / "after market" parts for the -95 LS, which is rare as a Ferrari here. It has to be the Lexus dealer or internet. I guess I will try to order parts from US, but shipping is a problem...

Or perhaps I will do like nc211 -sell it-, but do it BEFORE fixing all the issues. But I DO like the car...:cries:

/Alexander

Alex, good to see you around the watering hole again my friend! You've got a good point of selling it BEFORE fixing all the issues, instead of what I did, which was fix them all, then sell it. Hahaha... Kind of backwards math on my part. But, for me, the few thousand of dollars was like taking an auto repair class....chalked up to educational purposes....But whew, am I glad I graduated from that course!

If you're having that much of a problem with getting parts over there, then I hate to say it, but I think you're right. It's only going to get more expensive as the years and miles roll on too. What are the shipping costs if you were to order from the US and have them shipped over to you?

[Seb Harvey]

Sorry for digging up an old topic, but I have experience with this problem which may help some people.

Check your front brakes for ceasing, which will add presure on the brake disc.

The front brakes use pistons to sqeeze the brake disc, there are 4 pistons per front caliber, it will only take one of these to fail. When you drive, you may notice no vibration for the first 15 minutes or so, but as the discs warm up and expand, they bind against the pad which has ceased causing one front wheel to essentially want to move more slowly than the other. This causes your vibration.

If this goes on for long enough, or you have old discs, they may have been warped.

Try and find a genuine refurbished caliper, have it cleaned and ensure it works.

This solved my problem, after months of wheel alignment, balacing, new discs, new pads.

If you have a vibration under braking, check the shims on the caliper are wide enough to prevent the pad moving in the caliper, as this too causes vibration, but more noteably under braking. The shims are tiny little things that are sandwiched between the caliper and the pads. (Sometimes shims can fall out during brake pad changes or you may have the wrong sized brake pad in).

Hope this helps some people.

[Blayd]

Ive known a few pple who just ended up having a bent rim. Seems like those bend easy or something on the Lexus cars. Doesn't SOUND like the prob here though.

[lsb4588]

Helllp.... everytime i brake or turn my car vibrates' i just replaced my rotors and brake pads and it stoped for about a day and started again' and the garage said it could be my bushings from my front lower conttol arms

[VBdenny]

I suppose if our roads were not so bad, I wouldn't have alignment issues but that will not happen. Even with pretty much worn out tires, my car still rides quite smooth. There is a very slight vibration between 80 and 90 which I'm pretty sure is the tires. Getting really hard to buy V 15's anymore so I have put it off.

The part about the worn bushing was interesting. I'll have to address those things in the next year.