818LS400

hey, i have a 1991 ls400 i got about 150k miles on it i love it and i hope to give it another 150k, lately when i put it into gear the car has a really nasty jerk, it feels like someone hits me from the back everytime i put it into drive, if anybody has any ideas what it can really be please let me know. Thankss

GRAND_LS 4

iTrader: (2)

when its the last time you changed your fluid?

KilaWombat

iTrader: (1)

I had my tranny fluid changed, but still get this jerk sometimes also. What else can it be?

91LS400vgb

Could be the rear engine mount, aka transmission mount. It has been discussed before and seems to be easy to replace.

dac

also check the drive shaft for loose bolts and the rubber doughnut coupling

818LS400

ok thank you, ill keep all that in mind if you guys get any further info please let me know, because i really dont want to get my tranny rebuilt.

justincook

OK I've done lots of searching, sounds like it is fairly easy to put a jack under the tranny and replace the mount. My question is where do I place the jack? Is the pan sturdy enough to support the tranny?

My 96 also slams into gear -- especially when it is on fast idle. I really hope this helps.

dac

jack the car up with a trolley jack then use Axel stands for safety reason then yes use a standard jack to raid the gearbox ( not on the pan though ) jack it from the rear of the gearbox where the prop shaft goes in

HKSC430

are you sure it's the transmission causing the jerk?

rear differential (gap) problems can cause jerking as well...