RoMiLex

Ever since ive had my 98 GS400 the way the transmission shifts has always concerned me. Being a car more aimed at luxury I can understand having the shifts being a bit soft and lingering. But then how do you really know if its acting normal or if the transmission is slipping during gear shifts? While it does have 233k its a Toyota, and they last forever if you stay up on the maintenance.

Lukas99GS

Well a transmission isn't going to shift perfectly forever, especially with that kind of mileage, it's not gonna be like new, especially if previous owners didn't change the fluid as often as needed, also an old transmission mount can cause weird feeling shifts

GRANYZ400

iTrader: (1)

OP: Are you specifically referring to the 1-2 shift? If so, I have the same concern. My GS4 seems to "lag" at WOT when performing its 1-2 shift. I have watched countless YT vids of 0-60 runs to see if I could "hear" the 1-2 "slip" in other GS4's (or see it on the tach). I cannot tell if mine is normal or not. All I can think of is perhaps posting a good video of an acceleration run and being specific about your concern.

Not to threadjack, but if anyone has a comment on my 1-2 "slip" concern I am all ears. My car has 120K and is well maintained, with fresh Toyota AT fluid change (not flush) and no burnt dipstick smells or anything else weird. Also, I don't run it WOT very often.

JLAWS

Have you guys ever change your motor mounts? Made a huge difference when I swapped out the 2 motor and 1 transmission mounts. Both of my engine mounts on my old 99 Gs400 with 130K miles were gone. I had a terrible delay and then slam into gears when I floored it. I believe the engine was lifting way up when I floored it and delayed the power to the drive train. There was a night and day difference once I had the motor mounts changed out. Smoother and more refined acceleration.

Lukas99GS

Just curious, was your car shaking or anything from the bad mounts? I've got a delay/hesitation thing going mostly when taking off from low speeds. My mounts have never been changed and I've almost got 210k now, did you just go oem and how was the labor?

DMPesso

I hope your joking! Don't even think about keeping the GS if you haven't changed the mounts yet! It's like a night and day difference especially at your mileage, it's gonna feel so smooth you won't even be able to tell the engine is running. I can't believe you went that long on original mounts, kudos to you for that brave decision!

Lukas99GS

Hmm, I'll probably replace them then, although I had no sighs they were going bad! My car doesn't shake or vibrate or anything

GRANYZ400

iTrader: (1)

Same thing here at 120K. Nothing strange other than my 1-2 gear change concern. It doesn't slam into gears and it's a rocket still. However, if I can transfer power better to the ground by reducing engine flex, well, that would be great (depending on the cost!)

JJaySilver

Speaking of the mounts (not trying to jack thread), I feel small vibrations at idle in park or drive, and also feel a rough shake whenever I turn off the engine. Maybe its a sign telling me to replace all mounts.

RoMiLex

Funny what happens after someone says "not to thread jack".

So I have replaced my driver side motor mount because the engine was jumping around like a a fish out of water. I tried to get to the passenger mount but my issue is that I can get a tool on it but then I cant move the tool. It hits other things in the area. I started a thread asking about it to get some help and i had probably two responses that really didn't help at all.

Some of what I mean is 1-2 shifts that even at partial throttle are slow and the RPMs go up further than they need to. Not that its holding it in gear its like it goes out of 1st, raises PRM, then goes into 2nd. Then at WOT it takes way too long for a 1-2 shift. Even in Power ECT mode.

DMPesso

bad gas can also cause this as I notice this sometimes with different gas especially with crappy BP, but change the mounts if you havent yet, you WILL notice the difference!

DMPesso

I saw the mechanic do it, you need to jack up the motor as much as possible until it doesnt go up anymore, then youll be able to access the mounts

JLAWS

Even at only 85K miles my 2005 GS430 mounts were bad but didn't feel as bad as my 99 GS400 with bad mounts.
There is no way to visually inspect the mounts itself to see if they are bad. A quick way to check is get the engine up to operating temp and put the AC on and observe if it runs smoother with it on vs off. If it vibrates when off like it needs a tune up then the mounts are bad. Another way requires 2 people. Have someone put it in gear and hold the brake and step on the gas. You'll most likely see the driver side move up in the air if the mount is bad. I'd only go with Oem mounts. The transmission mount is very easy to change . Make sure you have a jack to keep the drive shaft up so it doesn't drop down . The 2 motor mounts are very difficult to do. I had my master tech mechanic change them. He had to take the inner control arm bolt off which allows more clearance to jack the engine up to gain access to the mount bolts. Then once done he did a front wheel alignment.

DMPesso

I DEFINITELY have that issue. Without the AC the car is slightly rough, but once you put the AC on its smooth as butter. But I don't remmeber that going away when I changed my mounts. I already changed all the mounts twice. You think they would go bad in less then 20k miles because of hitting a hard pothole? Come to think about it I have been hearing a nice clunking over slightly raised roads that sounds exactly like the mounts would sound. I definitely hit a few huge potholes that were so bad my alignment got knocked off. Damn these mounts are weak, they probably are shot again!

Lukas99GS

Just curious how much you paid to have them changed?