Vibration From 40-60 Mph

[91 Ls4]

Hay guys new user, I have a 1991 Lexus Ls400 i get a vibration from 40-60mph once every so often. It lasts maybe a second or two feels as if my phone/pager vibrates on your belt! The car has been balanced road tested and everything. Maybe someone has had this problem and can help me out.....?

[silvermate]

hello welcome

there was just a topic on this a day or so ago, scroll down and take a look, it might be on the second page.

[CUMan]

Does it feel like you are running over rumble strips placed on the road? Does it happen when the transmission is downshifting when going up a slight incline?

If so, this is a very common problem on the first generation cars.

My 93 LS did this until I had the transmission fluid drained and refilled. This was about three years ago, and the problem has never returned.

Make sure you use the right fluid. My 93 calls for Type II fluid, which is no longer being made. The Toyota Type IV is its replacement. I am not sure which fluid a 91 LS would need.

[91 Ls4]

Does it feel like you are running over rumble strips placed on the road?  Does it happen when the transmission is downshifting when going up a slight incline?

If so, this is a very common problem on the first generation cars.

My 93 LS did this until I had the transmission fluid drained and refilled.  This was about three years ago, and the problem has never returned.

Make sure you use the right fluid.  My 93 calls for Type II fluid, which is no longer being made.  The Toyota Type IV is its replacement.  I am not sure which fluid a 91 LS would need.

←

Thanks, actually no its seems to just hesitate for a spit second and thats it.

[JIBBBY]

Hay guys new user, I have a 1991 Lexus Ls400 i get a vibration from 40-60mph once every so often. It lasts maybe a second or two feels as if my phone/pager vibrates on your belt! The car has been balanced road tested and everything. Maybe someone has had this problem and can help me out.....?

←

Your transmition mounts need to be replaced, this is the most common in older v8 lexus's, this problem causes vibration at shifts, or just at certain speeds.

[Old LS]

Does it feel like you are running over rumble strips placed on the road?  Does it happen when the transmission is downshifting when going up a slight incline?

If so, this is a very common problem on the first generation cars.

My 93 LS did this until I had the transmission fluid drained and refilled.  This was about three years ago, and the problem has never returned.

Make sure you use the right fluid.  My 93 calls for Type II fluid, which is no longer being made.  The Toyota Type IV is its replacement.  I am not sure which fluid a 91 LS would need.

←

That sounds like the same problem I have. It feels like I'm driving on dirt road. I'm not sure it happens when shifting down. It happens when I'm driving around 40-50mph and it lasts few seconds. So does that caused by bad tramsmission fluid? I just spent $800 to replace the water pump and timing belt. Hope it won't cost that much this time.. Thanks for the tip!

[KY350]

Make sure you use the right fluid.  My 93 calls for Type II fluid, which is no longer being made.  The Toyota Type IV is its replacement.  I am not sure which fluid a 91 LS would need.

←

91 LS requires Type II fluid also, but as unavailable, Type IV should be ok.

[90LS400Lexus]

My 1990 LS400 also did this. It was a "fluttery" type vibration. Upon advice- I had the transmission fluid changed out- no change. I tried everything. I finally took it to the local Lexus dealer for inspections. Turned out that the tires had "cupped", because when I had an independent repair shop install new rear struts, they did not re-align the car- hence the tires being ruined.

That was the problem with my car, but cannot say for sure if your tires are the culprit.

Good luck!

[95LS400Bob]

Mine was transmission and motor mounts. Vibration came in about 45.

One thing you might test and it helped us find it.

2 people required.

Start the car in park..hood up and you work the throttle cable and have one person feel steering wheel for vibration and watch the seat back. About 1800 rpm (as I remember)....the wife said she could feel vibration through the wheel and the see the seat back vibrating slightly.

Then we replaced all 3 mounts....did it again...no vibration anywhere...any rpm. Test drive and vibration gone.

To tell you the truth I really thought it was in driveline carrier bearing or driveline alignment. Because you could "drive through the vibration." But it was mounts.

[sainikai]

Hay guys new user, I have a 1991 Lexus Ls400 i get a vibration from 40-60mph once every so often. It lasts maybe a second or two feels as if my phone/pager vibrates on your belt! The car has been balanced road tested and everything. Maybe someone has had this problem and can help me out.....?

←

I had the same problem until this summer when someone suggested to change transmission fluid and refill from pan. I did if the first time and it went away although I changed fluid 3 times after that (Didn't want to go for fluid flush).

-sainikai