Patsum

I have a 91 ls with 165K on it and when I go from neutral or park to ANY gear forwards or backwards it will jerk forward or backwards.

Drives great otherwise.

I am guessing a mount is completely shot somewhere. I also feel a ridiculous amount of vibration from my shifter **** and zero vibrations anywhere else in the car including steering wheel

idea's?

steve2006

Common problem and as you have already mentioned replace your motor mounts and transmission mount.
Easy way to check motor mounts is to get some one to rev the engine while you watch the engine, if the engine moves excessively side to side they are shot.
Motor mounts are not too bad a job to replace and neither is the transmission mount.

This will help you

https://www.clublexus.com/forums/ls4...on-mounts.html

timmy0tool

iTrader: (7)

gear engagement is usually a bit harsh esp if the car is still warming up (reving at 1.5k). it should drastically decrease in feel when the motor is at idle speeds though there still is a distinct tug to let you know it's in gear. a failed motor mount can be felt during driving.

Patsum

I cannot feel anything while driving except through the shifter holding it...

The car jerks just the same forward or backward when cold or warm. no difference. My Tach has been broken so long who knows what the hell my idle is. the car runs great though

I'll check the motor to see if it rocks while revving. I doubt it is that though. betting it's the tranny mounts.

PerpLexusd

I had that before to my LS it was the worst from a cold start,

I thought it was the mounts also but turns out for me it was the transmission fluid had gone bad. I hadn't replaced it since I owned the vehicle. what I did was drain the pan then filled with the toyota type IV atf drove it around for a week or so it got a little better then drained the pan again filled with toyota type IV atf drove it around some more then did it again and added the lucas no slip with it, now it's smooth shifting...

I still haven't replaces my motor or transmission mounts the gear shifter shakes a little but nothing drastic and i have well over 200k on my car I think i'm already in the 300's (not 100% sure because I had to get a new guage cluster old one was at 230, the new one was 70k and now is 140, sooooo 300?)

Patsum

Interesting.. I am not the the tranny fluid has ever been changed on this car in all its 165K miles

I am hesitant to do that because every single tranny problem or failure I have ever heard of was surrounded by shortly after someone changes the fluid. I came from an RX300 and that would everyone's worst nightmare

I will consider it and check the fluid color soon.

PerpLexusd

yeah, don't do a full flush right away, you'll go from a jerking transmission to one that doesn't go into gear.

do it gradually so everything can get used to the new slippery fluid a little at a time. maybe do one pan (about 2 quarts) a month even. the whole system holds about 7 quarts according to lexls.com, so it'll slowly mix in with the old fluid and kind of recondition all the internals and the lucas no slip works really well too

kainedogg

Might I add checking the bushing that holds the rear differential in place. It too can cause the issue you mentioned.

billydpowe

iTrader: (1)

if you check the mounts like Steve told you to, have whoever rev's the engine up be sure and hold the brake on, check it in reverse & drive.
I am sure you need a tranny mount, but they are the easiest and cheapest thing you con do...
and if you check on the differential, they are 3 bushings that usually cause problems..