vsop4me

Hi everyone...recent owner of '99 GS300 with 160k. Been reading a lot of posts to get familiar with the car. Car was recent serviced and everything runs smooth. Based on advice from this forum, I decided to change the lower ball joints and transmission mount as both were originals. Thanks to some great posts, I was able to get both done this morning.

However......taking a test drive, there is now car is shaking at idle ~600 rpm but only in drive, not in park or reverse. I suspect it is the new transmission mount, it is OEM Toyota. I did have to jack up the tranny just a bit to get the new one is so it was somewhat compress, needing replacement regardless. Driving eliminates shaking. I am wondering if the new mount has shifted the tranny up and maybe has introduced the shaky because of other worn mounts that was, overtime shifted to adjust the old mount.

I have double checked all bolts/nuts, all tight, including the lower ball joints but driving turn seems good so I don't believe changing the ball joints contributed to the problem. I took all precautions based on recommendations for the car as well as the tranny during the replacements, I am usually pretty good at being careful and following instructions.

Any advice would be appreciated.

And thanks to all those the have posted instructions, they made the job so much easier.

username32

I recently replaced my engine and trans mount although not a GS, i havent had any issues. Maybe the rubber needs some time to get broken in?

vsop4me

Went under the car again today and everything checks out okay. I'm going drive it for a few days and see if it settles in. Took it for a short spin today and upon acceleration, feels like it shutters, almost like its about to stall but it'll accelerate fine. No problem during drive. It's been cold here in Denver so will see if it gets any better when it warms up later this week.

vsop4me

Update from today.....so after searching and reading more last night, I decided to reset the ECU. Drove it to work today and it is much better, not sure at this point if it's the ECU reset or the settling down or something else but will report later on. I am getting that dreaded low idle shake but it seems very intermittent this morning driving to work but rarely on the way home....hmmm some interesting quirks on these cars

SC4Paulo

iTrader: (2)

New transmission mount = raised transmission = motor gets shifted differently than before = not properly seated in work motor mounts = vibration

vsop4me

Hi Paulo - I thought about if that may be the case....I suspect I may have to replace the motor mounts as well but here's some more info.

Been driving to and from work and here's what my observations are:
- It is a lot better now than when I first replaced the transmission mount but slight shake is still there, not much but noticeable.
- Interestingly, I appear to have discovered the low idle complaints that many have raised on this forum regarding the Auto Mode for temp control and it testing that, I did notice the low idle shake when car slows down to a stop, rpm drops to 450-500, then backs up to about 600 and settles there. I also notice that this does not happen when the AC light is on, again appears to be that the computer increases rpm and sits at about 700-800.
- The slight play or jerk that I noticed when shifting and on acceleration after releasing gas pedal is still there, part of the reason why I wanted to replace the transmission mount.

I am guessing that at this point, I probably need to replace the engine mount and don't mind doing that, just want to make sure that I going do the right path to avoid spending more money than I need to. Outside of the jerk/play in shifting, the engine and transmission is absolutely smooth shifting and driving so I don't believe that is anything wrong with the transmission.

Are there other mounts on the front or rear of the transmission that may be worn or need to be considered?
I called a couple places and they are willing to replace the mounts for me for ~$260, I provide the part.

JLAWS

Did you buy Toyota/Lexus Mounts? I wouldn't trust anything else. A slight change in design can throw things off. They are not much more than aftermarket ones. Some Lexus parts sites sells the motor and trans mount combo at a discount I changes out my transmission mount myself and there was an improvement, When I had my motor mount changed out it drove much more refined. The acceleration delay seemed to have disappeared. I guess the delay was due to the engine and driveshaft moving/shifting with bad mounts.

vsop4me

Transmission mounts are Toyota OEM mounts. I am considering the engine mounts next and will also stay with OEM as well.

JLAWS

You'll notice a big difference if they were never changed. The only way to see how bad they are is if you have them in your hand. Mine were bad. The solid rubber bushing had a lot of cracks and chunks missing

repugnante

Change your engine mounts soon. Your tranny mount won't last for two months on bad engine mounts. The new tranny mount can't handle all of the torque that's supposed to be suppressed by the engine mounts and they will fail prematurely.

I went with DEA for the engine and tranny mount. Both were the EXACT same as the OEM's. Fit to perfection without any issues. The tranny mount appeared to be more solid in comparison to the OEM one. Can't feel neither the engine or the tranny anymore at idle and stopped at a light. Car is silky smooth.

SC4Paulo

iTrader: (2)

Yeah, my car feels the same way, at lights it vibrates like crazy I can see my motor move more than I'd like when I rev it from the throttle cable. I have had similar experiences with my sc, that's how I knew my GS needed motor mounts the first time I stepped in it. after your motor and transmission mount has been replaced and you get a thud from shifting, check your rear differential bushings. Those could be worn

Also my car idles at 200 rpm and that is not a typo.

vsop4me

Okay, looks like I should move to get the the engine mounts replaced, I'm fairly handy but I think I'll leave this the professionals...will take it to the shop. Also, I haven't done any searches yet on this forum (again, a freaking awesome community) but are the diff bushings a DIY project? I believe on some other cars, they can be a pain but not sure about Lexus. If I have a little bit of time, I'll go take a look underneath the rear, not sure if I can tell if they're worn or not. My car with AC off idles just sub 500 but I usually have it on full auto. I'll keep you all posted....

vsop4me

So sitting in a meeting at work and decided that I'm going to order the mounts and give it a shot at DIY....I read a few threads last night and it appears to be somewhat straight forward.

Lukas99GS

Let us know if that solves the problem! I'm thinking of changing all mine this summer

SC4Paulo

iTrader: (2)

I know differential bushings were available for the SC, haven't looked into GS but I already feel then start to wear out from reverse to drive