Tempest020

I just bought a 98 WS6 with an M6 tranny.

I'm getting excessive Shifter Movement & banging noise in 1st and 2nd under hard acceleration - already replaced trans and TQ mount with stock GM parts.

My biggest concern is that if you are rolling in 1st at 10-15mph and punch the gas the shifter vibrates bad left to right and makes a banging noise from underneath the car. till the car regains traction... **it also will still shake the shifter and make noises just stepping down hard and not breaking the tires loose, but is worse the harder you drive it... of course the exhaust is going to shake if the tranny and the rest of the car are as well so its not my biggest concern I'm replacing it with a borla after I get this problem figured out.

Part of the banging noise I believe is the exhaust hitting the under pan under hard acceleration. especially shifting to 2nd. the tires will break traction followed by a loud bang from under the car.

I'm not sure what else it could be... engine mounts maybe?

once you are in 3rd gear and up it drives normal no more excessive shifter movement even if you stomp it and shift hard 3rd, 4th, 5th etc. its only in the 1st two gears. I'm guessing from this its due to the torque in the 1st two gears.

Please help I've owned an 89 formula ws6 and stil own a 94 TA and never seen this before...

Thanks,

Michael

LS1Formulation

iTrader: (13)

What condition are your lower control arm bushings in? Kind of curious if they're worn out and the slop is causing wheel hop which transmits to the trans.

teke184

iTrader: (5)

agree with above.

i've had banging from the LCA not being tight enough when i swapped on the aftermarket ones.

motor mounts are my first guess though. poly units should solve the exhaust clearance problem.
my exhaust hitting the frame made some AMAZING sounds and vibrations when under load, and mostly just low gear driving.

poly motor mounts now, and the exhaust under the front seat barely moves 1/8" under hard load.

CW00BlackTA

iTrader: (31)

I was thinking wheel hop too. Does the rear end feel like it's hopping up and down?

Tempest020

I went and drove it again... its definately got some wheel hop under hard acceleration. It kind of shutters at high rpm's right before you shift two 2nd and really hops when you shift to 2nd along with a loud bang from underneath...

I looked at the driver side exhaust pipe and its been hitting on the underpan and farther back on the torque arm. I think most of the damage occured when the tranny mount was busted, but it still sounds like the exhaust or something is slamming the underpan when shifting into 2nd.

I'd say I have two separate issues... possibly engine mounts and a rear end bushing problems? what do you guys think?

I looked at the lca bushings but didn't have time to actually pull them off tonight just got home from my 2nd job... I honestly can't say they are or aren't worn out. They didn't have slop per say, but I'm assuming there is no way to know w/o dropping them and looking closer. I did notice the bushings on the panhard bar felt rotted or close to it. the lca bushings didn't feel as bad, but w/o taking them off to look I cant say for sure.

At 66k would you go ahead and replace the engine mounts just to be sure? I went with stock trans mount and t/a bushings b/c I drive it hard, but I don't drag race and I'd rather not have all the vibration with the poly that everyone is talking about on the forums.

Should I go with stock engine mounts or is it ok to go poly on the engine with the rest stock? I know the poly's would help keep the exhaust from hitting as bad as it does with the stock engine mounts, but wasn't sure how it would affect vibration in the car and if the stock t/a and trans mount would take it???

as far as the lca goes... I'm really wondering if I wouldn't be better off just installing new lca's altogether like the ones from umi??? They are supposed to be a direct bolt in with poly bushings.

any suggestions on the panhard bar.

Sorry for all the questions but this wheel hop and noise is pissing me off. my two other cars were automatics and never had this problem. except for a broken tranny mount once on them.

I really appreciate all the suggestions/help.

Michael

UMI Performance

iTrader: (77)

Yes our control arms are a direct bolt on that can be swapped out very easily. If you have any questions please let us know and we are glad to help.

Thank you!
Ryan

99_Z_155

iTrader: (7)

sounds like those guys could be right. i was thinking maybe your y pipe was hitting the floor. that makes a lovely sound too.....