director

1995 lexus ls400 has 170K miles. Runs good but transmission bumps when driving often when I move accelerator. Doesn't seem to do it when in cruise control. Independent transmission shop suggested fluid change and flush. Quoted $300 which seems high. The bump is significant. Is fluid change the right solution?

Elless400

Fluid replacement when you are unsure of it's service history is never a bad idea, however, a fluid issue would manifest whether using cruise or not.

Sounds like a worn transmission mount. If they haven't been done, I'd replace both front (engine) mounts as well as the rear (transmission) mount.

You can replace just the rear mount, but it will wear out quickly if the fronts are shot too. Best for them all to wear together.

lextout

throw your tranny in the garbage and get a tranny from the scrap for 300$ max, put new fluid in it and call it day, ez pz.

director

Thanks for the suggestions. My tranny mechanic says its good for another 30 to 40K miles without doing anything if I don't mind the bumps.

director

I don't know how to close this thread.

director

Here's the latest on bumpy trans. When I drive in 3rd gear locally or when using cruise control on highway, there is no problem with the bumping trans. Could it be a software problem?

director

Here's the latest on bumpy trans. When I drive in 3rd gear locally or when using cruise control on highway, there is no problem with the bumping trans. Could it be a software problem?

Banshee365

Have members here not already told you to change your rear transmission mount? I agree that is probably your problem. It’s easy to check by placing a floor jack on your trans pan with a piece of wood between to distribute the load and jack it up to see if the trans lifts off the crossmember. If it separates the mount is bad.

director

You're right. I just thought the additional info might spark a solution.

Banshee365

Your solution could very well be in the very first reply to your post. Check the mount as I described.

director

OK. I had engine and transmission mounts replaced. Still have the same problem. Works great in cruise control. is it possible there is a computer or electrical problem?

director

OK. I had engine and transmission mounts replaced. Still have the same problem. Works great in cruise control. is it possible there is a computer or electrical problem

RA40

iTrader: (6)

As a general suggestion this thread is one that all 90-98 may want to be aware of.
https://www.clublexus.com/forums/ls-...capacitor.html

dicer

Well we really need a better description of the problem. It bumps???? I've never had a transmission bump, unless it was loosely mounted.
Is it a harsh shift? Does it do it when starting out? Did you try putting it in forward gear then reverse with your foot on the brake pedal and car stopped. Maybe the bump is a drive line or rear end issue. You have to use a process of elimination to make sure its really the transmission that is at fault. Mounts? How about all the engine mounts? How about the mounts for the rear end? How about CV joints? Drive shaft? There are lots of things that can cause a bump. If it still has the problem why do you ask to close this thread out???? That statement makes zero sense. Unless a forbidden topic comes up the thread never closes out. Others may have the problem and want to see what to do to fix it and or add to it.

director

I'm not sure how to transfer the thread.