One Vibration Solved - Transmission Mount Was The Cure

[Slvr99LS]

Hey all... Here's the promised follow-up from my original post last week that mentioned some strange vibrations I was experiencing with this newly purchased '99 LS. When I originally went to look at this particular car a few weeks ago, as I was doing a customary 'walk-around' inspection, one thing I did is rev the engine up a bit with the transmission in Park and noticed it wasn't exactly what you'd call 'Lexus-smooth'. Actually I think a 15 year-old Pontiac Grand Am with the Quad-4 engine might've been smoother. Hmmmm. From the initial feel of it, if you tried to balance 17 wine glasses on this engine I think all you'd end up with was a bunch of tiny shattered glass shards and an aluminum V-8 drenched in your favorite choice of vino. It had a particularly rough spot near the 2K-RPM range that varied in intensity above and below. Duly noted. I didn't bother mentioning anything I found to the owner of the car as my belief at this point was that his mechanical aptitude was limited to putting the key in the ignition and adding fuel every few hundred miles. Anyhow... my thought at the time was "probably not a deal breaker", but I was already seeing $$$ signs dancing in my head. With that said, unfortunately I bought the car somewhat spontaneously without the benefit of a high-speed drive either as I ended up viewing the car in the middle of a large, highly-populated city during rush hour. Retrospectively, I realize this action in and of itself wasn't too bright (I never claimed to be bright) and goes completely against my grain under normal circumstances. What can I say. I was antsy for an LS!

In any event, to make a long story short after looking at a LOT of these cars over a period of months, I decided to take the plunge because this seller had an alternate buyer already waiting in the wings... so it was a case of "buy-now-on-the-spot"... or let it go and keep looking. Just couldn't let it go... it had the very desirable (to me) Nakamichi stereo, excellent overall cosmetic condition, was owned by the same family since new (that much I was able to confirm), had a decent level of maintenance for most of its life (apparently up until the last couple of years), and was painted in what my eyes view as a great color. Once I got it home and had a chance to really spend some time with the car I began to question whether I'd make a huge mistake. Classic case of buyers remorse when reality sets in and completely eclipses initial excitement. What a buzz kill. Kind of a sucky feeling, particularly when you've just dropped enough cash on a purchase to finance the government operations of a third-world country for at least an hour.

In a nutshell, that earlier noted mid-RPM vibe translated out on the road into a fairly loud, low-pitched thrumming/humming sound right where you spend a lot of driving time... the 40 - 55mph band. I was really thrilled with myself at this point. Smell the sarcasm? The car also has notably warped rotors and some clunking & banging going on in the front end over certain types of bumps. Multiple issues. Ok, no need to freak out... I think. Like a late-night Poker hand gone wrong, I was kinda feeling 'pot-committed' at this point. With 161K on the clock, I do realize virtually ANY used automobile is going to need some type of work. The unknown question is how much work. On some cars I've owned it just seems to never end. Considering Lexus parts pricing, I was praying (and still am!) that this isn't one of them. In any event, I'm fairly mechanically savvy in my opinion and do the majority of my own work, so the first thing to do is get under the car and spend an afternoon getting dirty. I call it 'vehicular-bonding'. I could make a far more human analogy but I'll refrain for the benefit of any female forum readers who may be out there.

Anyhow, first thing: Flush every fluid from stem to stern. Mobil-1 synthetic 75w90 gear oil in the differential (not much metal stuck to the factory magnet - a good sign), 6 quarts of correct Toyota T-IV trans fluid (drained the pan twice - fluid was pretty ugly), oil and filter change (OEM Toyota filter), power bleed the entire brake system with the specified DOT-3, etc. The good news is that the underside was completely dry and since the car was garaged the majority of its life and seemingly not driven much in foul weather, so it wasn't a rust bucket undernearth. What a treat. Slight attitude change at this point. Maybe this won't be so bad after all. Fingers crossed. After many late nights reading this and other Lexus-specific forums (which I have to say has been a HUGE help overall - thanks to ALL!), I decided to make the transmission mount a focal point since it was seemingly one of the least-costly, easiest-to-change components on these cars which had the potential to make a significant difference. I will say at this point that doing a simple visual inspection of the mount with the car up on a lift showed exactly nothing. The mount looked normal in the sense that it wasn't horribly deformed or visibly broken. No matter, it definitely looked original so out it came. Now, this is where the story gets interesting. This site has been such a valuable resource of information already, I feel the least I can do is try to give a little back and hopefully assist someone else in solving their own troubles with one of these cars.

With that said, it was only when a brand new transmission mount is compared side-by-side directly with an old mount with some real miles on it that it becomes painfully clear what occurs. Not only was my old mount compressed roughly 1/4 inch in overall height, which changes the all-important driveshaft angle, but once the weight of the transmission itself had been removed, it was obvious the old hardened rubber had actually cracked and broken free of the mount on both sides! My optimism that this mount may solve at least one issue was definitely rising now. To keep this post from reaching Biblical length, I'll state that once this $45 dollar part was installed, the difference was literally 'Day & Night'! The driveline vibration... completely gone. Wow. 50mph was now glass smooth, along with all other tested speeds. Subsequent close analysis of the old mount shows clearly what causes the vibration. The engineers built-in sort of a 'fail-safe' to prevent the mount from completely collapsing with age. It's equipped with a snubber that when enough degradation occurs, the two pieces compress enough it defeats the design intentions of the mount by allowing the top and bottom halves to contact one another and literally pass driveline vibration straight through to the body of the car. This was the cause of the harmonic 'hum' which varied with engine speed. Sure the rotors are still warped and give the sensation you might lose a filling or two when applying the brakes, and the front end bangs in a decidedly un-Lexuslike manner entering certain driveways with a sound more akin to an '86 Yugo on it's last legs, but hey... one thing at a time here! Rome wasn't built in a day and I consider myself a realist, so let's face it - even a Lexus ages. So my advice at this point would be: anyone with a similar type of driveline vibration... if you're on the fence about it - go ahead and replace that aging transmission mount. It's a dozen bolts 'n nuts and about 45 minutes of your time. It sure can't hurt! I'm going to try and attach 2 photos to this post. Assuming it works, the first pic is the brand new mount. In the second photo, it may be tough to tell but look closely and you'll see that the rubber on the old mount has completely sheared from the metal base. The amount it has compressed over time may not be quite as obvious, but believe me, it's there. More posts to follow as I delve into the front-end shortly with wallet wide-open and new-found optimism...

[erg1948]

Great post! Entertaining as well. I too have a '99 LS with pretty much the same symptoms. Just turned 90k, so it goes in next week for the full load of service, plus a tranny mount, strut rod bushings (the "banging" you are experiencing) and a fix for the infamous "click" when attempting to engage the starter. Yes, wallet wide open and a load of plastic to back it up :( .

Gene

[lexfourcam]

im goin to replace my mount soon thanks for the post. i have a 94 ls i thought the installation of the mount and the removal of it would be hard but now that i know that its not too hard im goin to get my mount ordered. my car shakes like a !Removed! if u push it down to much right before it shifts and when im at like 65 the shifter vibrates like crazy. i kno i feel exhaust vibrations from the str8s and headers, but it sure didnt used to do that, thinking i might need tranny and engine mounts but like you said one thing at a time.

[Slvr99LS]

im goin to replace my mount soon thanks for the post. i have a 94 ls i thought the installation of the mount and the removal of it would be hard but now that i know that its not too hard im goin to get my mount ordered. my car shakes like a !Removed! if u push it down to much right before it shifts and when im at like 65 the shifter vibrates like crazy. i kno i feel exhaust vibrations from the str8s and headers, but it sure didnt used to do that, thinking i might need tranny and engine mounts but like you said one thing at a time.

Sounds like you're going to do the work yourself. Good deal. On that note, I'll throw in a couple more quick thoughts. One thing I neglected to mention when I posted last night about the trans mount is what tools were involved. Basically an ordinary metric socket set, and a small bottle jack, along with a piece of wood to support the rear of the transmission while you unbolt the mount. Put the wood on top of the jack and raise the jack just enough to take the weight off the back of the trans. It won't take much of a lift. For consistency, I also used a torque wrench for reinstalling all the bolts/nuts along with one drop of medium-strength Loc-Tite on each thread for nothing other than piece-of-mind (probably isn't really necessary). Can't say for absolutely certain that your '94 is 100% identical to a '99, but my understanding is they're built on the same basic chassis so my belief is the procedure for replacing your mount will be essentially the same. Once the old mount came out, I was stunned how much higher the jack had to be raised up to get the new mount bolted in... this was due to the fact the old mount had compressed so far! I was praying I didn't (and hopefully won't) need the engine mounts as well since they look to be a LOT more work to change than the trans mount was. Like I mentioned, I went after the cheapest/easiest part first. Once in a while, you luck out. Still have plenty more work to do though, but I think I can see the light now at the end of the tunnel. Look forward to hearing how you make out with yours.

[lexfourcam]

thanks for all the info, i can't wait to get started and see the results. im hoping my transmissions gonna shift good everytime. my check engine comes on once and a while too. Its a lil *BLEEP* thought because when i want to get it checked out it goes off it doesnt stay on too long. im also gonna get my exhaust leaks fixed when i unbolt the exhaust im going to put new gaskets and get the pipe bent to perfection and get any holes welded.

[Slvr99LS]

Gene, thanks for the reply and compliment. Regarding your '99, are you going to have all the work done by a Lexus dealer or an independent shop? You mentioned 90K, so I'm guessing they'll be doing the timing belt, water pump, idler pulleys, accessory drive belt, possibly crank and cam seals, along with the trans mount, strut rods, etc. etc. Another friend of mine has a '91 LS with about 125K that's still on the original T-belt (yes, he's driving on borrowed time... and knows it)... if you don't mind sharing it, curious what that full service ends up costing when all is said and done. Even realizing that the costs of service varies about as wildly as opinions on what beer tastes best, I'm still certain there are plenty of people who could potentially benefit from your upcoming experience. I know I've said it before, but this forum rocks!

[90LS400Lexus]

I cant wait to replace mine. My '91 has nearly 220K and I am sure the mount is original. I get horrible vibrations (mostly through the steering wheel, so I bet my engine mounts are shot too), bu I am also getting occasional "bucking" on light acceleration when the car will reach where the throttle is. I am hoping its the tranny mount causing this. One tech told me it could be my torque converter. That would be my luck.

Anyone have the link to that place that sells the OEM mounts for $60?

I looked on ebay and mounts for a 95-00 LS are $53, but for the 90-94 they are $65 (from the same seller)... why are they that much more? They look the same to me.

[90LS400Lexus]

Another friend of mine has a '91 LS with about 125K that's still on the original T-belt (yes, he's driving on borrowed time... and knows it)...

At least one good thing is that is a non-interference engine. ;)

[Slvr99LS]

I cant wait to replace mine. My '91 has nearly 220K and I am sure the mount is original. I get horrible vibrations (mostly through the steering wheel, so I bet my engine mounts are shot too), bu I am also getting occasional "bucking" on light acceleration when the car will reach where the throttle is. I am hoping its the tranny mount causing this. One tech told me it could be my torque converter. That would be my luck.

Anyone have the link to that place that sells the OEM mounts for $60?

I looked on ebay and mounts for a 95-00 LS are $53, but for the 90-94 they are $65 (from the same seller)... why are they that much more? They look the same to me.

Did a little hunting and found a Lexus dealer which has the mount for your first-gen LS priced currently at $50.55 ... not sure what the differences in the trans mount are between the '90-'94 cars and '95-'00, likely some minor detail change but they do carry different part #'s. In any event, here's the direct link: http://www.trademotion.com/partlocator/index.cfm?siteid=214082&catalogid=0

[90LS400Lexus]

Ah, thanks for checking that and the link! Yes, I remember now, it was that place that had it before for $59.99 which was the cheapest one I had found. Seems its cheaper now and lower than the one I found on ebay. I am going to order it tonight or tomorrow and replace it posthaste.

[erg1948]

Gene, thanks for the reply and compliment. Regarding your '99, are you going to have all the work done by a Lexus dealer or an independent shop? You mentioned 90K, so I'm guessing they'll be doing the timing belt, water pump, idler pulleys, accessory drive belt, possibly crank and cam seals, along with the trans mount, strut rods, etc. etc. Another friend of mine has a '91 LS with about 125K that's still on the original T-belt (yes, he's driving on borrowed time... and knows it)... if you don't mind sharing it, curious what that full service ends up costing when all is said and done. Even realizing that the costs of service varies about as wildly as opinions on what beer tastes best, I'm still certain there are plenty of people who could potentially benefit from your upcoming experience. I know I've said it before, but this forum rocks!

Sure, I would be happy to share all info when the work is done. I am having the work done by York Automotive in Boring, Oregon (note the comma!), starting this coming Wednesday. Boring is about an hour's drive from where I live, but the shop owner is a Lexus-certified mechanic who decided to start his own business. He did most of the maintenance when I had my '90 LS, and I was always happy with his work. He charges substantially less than the Portland-area Lexus dealer. I trust him enough that I told him to just do whatever he thinks the car needs. When I scheduled the work he mentioned most of the items you pointed out in your post, plus 100% fluid changes, spark plugs and wires. The starter I have a question about. He said he would just replace the contacts; I might ask him to replace the starter instead.

Gene

[SKperformance]

Glad it worked, as noted on my replacement thread a few months ago , the mount is easy enough to do but is a drastic change for $50.

I also have a 2-3000k rpm oscialtion from the engine . I am not sure what it is yet but it was felt much less with the new mount.

Now follow the rest of that thread and change your coolant temp sensor and have a car you never knew you bought or could afford ,it really is an amazing $100.

[curiousB]

Coolant Sensor? I was following along with interest then got lost. What was the coolant sensor in reference too?

[90LS400Lexus]

Ah, thanks for checking that and the link! Yes, I remember now, it was that place that had it before for $59.99 which was the cheapest one I had found. Seems its cheaper now and lower than the one I found on ebay. I am going to order it tonight or tomorrow and replace it posthaste.

Guess I wont be getting it - not now anyway. I am not much of a credit card person, so I only have one that I requested a CL of $1000 on that I mainly use to get a rental car when we go on vacation. I had $59.00 left on it - the part was $50, shipping $5 which would have been $55... all is well, right? No, I go to place the order and it adds another $6.00 handling (it dont show you this until you place the order and type in ALL of your information), taking the total to $61.61. Pathetic isnt it?

Oh well. Not meant to be I guess.

[Slvr99LS]

Ah, thanks for checking that and the link! Yes, I remember now, it was that place that had it before for $59.99 which was the cheapest one I had found. Seems its cheaper now and lower than the one I found on ebay. I am going to order it tonight or tomorrow and replace it posthaste.

Guess I wont be getting it - not now anyway. I am not much of a credit card person, so I only have one that I requested a CL of $1000 on that I mainly use to get a rental car when we go on vacation. I had $59.00 left on it - the part was $50, shipping $5 which would have been $55... all is well, right? No, I go to place the order and it adds another $6.00 handling (it dont show you this until you place the order and type in ALL of your information), taking the total to $61.61. Pathetic isnt it?

Oh well. Not meant to be I guess.

For the record, I'd be more than happy to donate the extra $2.61 to the cause as long as you solemnly swear to buy the mount, the whole mount, and nothing but the mount. I'm sure that '72 Caprice could use a fan belt or a new set of points, but in this rare case, your LS has to take precedence. Speaking of 1972, man do I miss my boat-tail Riviera. 455 cubes under that mile-long hood and a huge Rochester 4-barrel... that car could pass almost anything... except a gas station.

[90LS400Lexus]

For the record, I'd be more than happy to donate the extra $2.61 to the cause as long as you solemnly swear to buy the mount, the whole mount, and nothing but the mount. I'm sure that '72 Caprice could use a fan belt or a new set of points, but in this rare case, your LS has to take precedence. Speaking of 1972, man do I miss my boat-tail Riviera. 455 cubes under that mile-long hood and a huge Rochester 4-barrel... that car could pass almost anything... except a gas station.

lol. Thanks. :D

Well, if they would bill me for the $2.61, I would send it by money order :D - I have it, but only in cash. :( I guess when I make my next payment I will be able to get it. :) Hopefully it wont take too long to post and I can complete the order by my credit card. :)

Yeah, the Caprice is tucked away and can rest. :)

Nice '72 Rivvy - I had a '72 Electra (same 455 engine) and I loved it! True, it would pass anything but the gas station. I wish I had of kept it.

Photo from 2002 when I owned it... (it was like new on the inside) Sold to a guy in Rock Hill South Carolina for $1800! It also had the rare gear shift wiper control button option.

[Slvr99LS]

For the record, I'd be more than happy to donate the extra $2.61 to the cause as long as you solemnly swear to buy the mount, the whole mount, and nothing but the mount. I'm sure that '72 Caprice could use a fan belt or a new set of points, but in this rare case, your LS has to take precedence. Speaking of 1972, man do I miss my boat-tail Riviera. 455 cubes under that mile-long hood and a huge Rochester 4-barrel... that car could pass almost anything... except a gas station.

lol. Thanks. :D

Well, if they would bill me for the $2.61, I would send it by money order :D - I have it, but only in cash. :( I guess when I make my next payment I will be able to get it. :) Hopefully it wont take too long to post and I can complete the order by my credit card. :)

Yeah, the Caprice is tucked away and can rest. :)

Nice '72 Rivvy - I had a '72 Electra (same 455 engine) and I loved it! True, it would pass anything but the gas station. I wish I had of kept it.

Photo from 2002 when I owned it... (it was like new on the inside) Sold to a guy in Rock Hill South Carolina for $1800! It also had the rare gear shift wiper control button option.

Must say... that is one fine lookin' Electra you had there from the era of the land yacht... with GM perched on top of the mountain. A 5,000 pound slice of a bygone era. Tough to comprehend, especially right now, but General Motors once owned literally about a 50% slice of the automotive pie. What a tragic fall from grace. Fact is, I've been a GM owner most of my life. While the ownership experiences over the years have definitely been a mixed bag, on balance I'd say the positives have surely outweighed the negatives. Genuinely hope they emerge out the other side of this recession as something other than a government controlled entity forced to build hideous Washington-mandated cars that absolutely no one wants... even with huge tax breaks and incentives factored into the equation. Garbage is still garbage even when it comes attached to a seemingly attractive price tag. This country has some of the brightest, most passionate engineers on the planet when they're not continually hamstrung by the bean counters and office politics... and can focus on what really matters - building great products that will stand the test of time. When a manufacturer provides some breathing room and encourages people to think 'outside-the-box', you end up with game-changing, landmark vehicles... like the 1964 1/2 Ford Mustang... 1966 Oldsmobile Toronado... or even the 1990 Lexus LS-400. By the way, the guy in Rock Hill, SC got a great deal. B)

[90LS400Lexus]

Thanks for that. Yeah, I loved that car.

Anyway, I wanted to update and post, I FINALLY ordered a new transmission mount from Lexus of Pembroke Pines. It was only around $62.00. I just dont use my CC that much and at the time, I had it maxed out. I paid it down alot, so I was able to get what I needed. I plan on changing the mount MYSELF and I HOPE and pray it stops most of my vibration and "chugging" issues, but I bet my engine mounts are still shot and the chugging could be the throttle body.

I will update when the mount arrives and I get it installed.

For the record, I'd be more than happy to donate the extra $2.61 to the cause as long as you solemnly swear to buy the mount, the whole mount, and nothing but the mount. I'm sure that '72 Caprice could use a fan belt or a new set of points, but in this rare case, your LS has to take precedence. Speaking of 1972, man do I miss my boat-tail Riviera. 455 cubes under that mile-long hood and a huge Rochester 4-barrel... that car could pass almost anything... except a gas station.

lol. Thanks. :D

Well, if they would bill me for the $2.61, I would send it by money order :D - I have it, but only in cash. :( I guess when I make my next payment I will be able to get it. :) Hopefully it wont take too long to post and I can complete the order by my credit card. :)

Yeah, the Caprice is tucked away and can rest. :)

Nice '72 Rivvy - I had a '72 Electra (same 455 engine) and I loved it! True, it would pass anything but the gas station. I wish I had of kept it.

Photo from 2002 when I owned it... (it was like new on the inside) Sold to a guy in Rock Hill South Carolina for $1800! It also had the rare gear shift wiper control button option.

Must say... that is one fine lookin' Electra you had there from the era of the land yacht... with GM perched on top of the mountain. A 5,000 pound slice of a bygone era. Tough to comprehend, especially right now, but General Motors once owned literally about a 50% slice of the automotive pie. What a tragic fall from grace. Fact is, I've been a GM owner most of my life. While the ownership experiences over the years have definitely been a mixed bag, on balance I'd say the positives have surely outweighed the negatives. Genuinely hope they emerge out the other side of this recession as something other than a government controlled entity forced to build hideous Washington-mandated cars that absolutely no one wants... even with huge tax breaks and incentives factored into the equation. Garbage is still garbage even when it comes attached to a seemingly attractive price tag. This country has some of the brightest, most passionate engineers on the planet when they're not continually hamstrung by the bean counters and office politics... and can focus on what really matters - building great products that will stand the test of time. When a manufacturer provides some breathing room and encourages people to think 'outside-the-box', you end up with game-changing, landmark vehicles... like the 1964 1/2 Ford Mustang... 1966 Oldsmobile Toronado... or even the 1990 Lexus LS-400. By the way, the guy in Rock Hill, SC got a great deal. B)

[billydpowell]

I have ordered two of them for my 97's. not really having any vibration, but I believe it will be smoother with new ones. They have 238k and 242k miles on them.

also have timing kit and tune up kit ordered, should be here this week, for the DWP.

[jainla]

Right before I bought the LS my trusty 240D was having vibration issues; usually when moving off the line. The whole car would shake. I was convinced that this was it; that it's going to be taken out behind the barn and shot. I took it to the mechanic and waited anxiously by the phone. Finally he called. Nervous, I picked up the phone. "It's ready come get it" he said. I said what was it? He said the transmission mount was shot. I said is there anything else that could cause this kind of problem? He said the motor mounts had seen better days. Go ahead and replace them I said.

You would think he replaced the engine; that little 4 cylinder diesel was suddenly as smooth as silk! Probably the biggest bang for the buck as far as maintenance items.

Glad it worked, as noted on my replacement thread a few months ago , the mount is easy enough to do but is a drastic change for $50.

I also have a 2-3000k rpm oscialtion from the engine . I am not sure what it is yet but it was felt much less with the new mount.

Now follow the rest of that thread and change your coolant temp sensor and have a car you never knew you bought or could afford ,it really is an amazing $100.

[90LS400Lexus]

Anyway, I wanted to update and post, I FINALLY ordered a new transmission mount from Lexus of Pembroke Pines. It was only around $62.00. I just dont use my CC that much and at the time, I had it maxed out. I paid it down alot, so I was able to get what I needed. I plan on changing the mount MYSELF and I HOPE and pray it stops most of my vibration and "chugging" issues, but I bet my engine mounts are still shot and the chugging could be the throttle body.

I will update when the mount arrives and I get it installed.

Wanted to update on this... got the mount, installed and it eliminated ALOT of vibration, but some still there. I guess the engine mounts are shot as well. :( Will do those when I can afford to spend money on it. Too many other things going on now.

The transmission shifts so much smoother too and no clanking sound when I shift into gear! Well worth $62.00.