trans_am_man

iTrader: (1)

Hey guys, Like the title says i have a 2000 trans am. I brought it to the shop who built and installed the steel drive shaft because there was vibration above 80mph, you can feel it at lower speeds but nothing too noticeable. I thought it was the drive shaft out of balance, but they put it on the lift and said the drive shaft did not shake. There was a slight clunking noise coming from the transmission while idling in 1st gear, no acceleration and no load on the tranny. One shop i called said that the tranny will make noise if there is not a load on it.

The shop that was looking at it said the Ds was fine and the tranny might need new bearings possibly but they wouldn't know until they took it apart. Gave me a quote of $1600 to install bearing kit and syncro kit.

My question is, if a bearing was bad would it cause this vibration at higher speeds? The car drives great and shifts fine, it doesnt pop out of gear or
anything.

Also i took off the cover over the shifter so i could see and feel the tranny while driving, i do not hear the clunking noise at while rolling slow or at normal speeds.

Any info would help? i dont have the money to fix it right now, and im nervous to try to tackle it myself.

thesource

iTrader: (60)

The trans will clunk without a load on it. As for the vibration goes, i would suspect the driveshaft as well. You can't just look at to determine if it's out of balance. It needs to be checked off of the vehicle.

trans_am_man

iTrader: (1)

They did take the DS off and put it on a machine but I didn't see it. I'm gonna ask to see it on the machine when I have them put a new slip yoke on. Also gonna have a the shop I go to check it out.

Still looking for some more opinions guys. Help me out

67SS&99SS

iTrader: (7)

Does it do it at 80 mph only in 6th? How about 5th or 4th gear? Have you lowered your car? Have you had the pinion angle checked?

wrd1972

iTrader: (12)

Cruise at 80MPH and use 4th, 5th and 6th gears. If the vibe is in 5th and 6th only but not in 4th, see this thread:
https://ls1tech.com/forums/manual-tr...vibration.html

If a bearing was bad, it would be growling and making a lot of noise.

trans_am_man

iTrader: (1)

It does it regardless the gear. I can take it out of gear and roll in neutral Nd it will still do it. I can hear/feel the vibration from about 50mph+ and from 80+ it's more aggressive and louder.

The car has stock slp springs from a 1LE ss camaro. It use to have the pro-kit.

I also have a umi tunnel brace adjustable torque arm set at -2.5 if I remember right. The car sits a little lower than a stock trams am, maybe like a ws6

Mikey 97Z M6

iTrader: (37)

Mine had a vibration when it had a cracked mainshaft lol....

Mike

wrd1972

iTrader: (12)

Since you slammed and you have an adjustable TA, I will have to blame the driveline angles. Make sure they are right, its easy to goof the positive and negative readings up especially if you look at them long enough. Damn things make my head go numb due to the simplicity.

I would not go 2.5 pinion down unless I were hard drag racing with big horsepower. Try about 1-1.5 degrees and check.

trans_am_man

iTrader: (1)

I took it to my mechanic that I always go to, he's the one that set the pinion angle. He drove the car and says he is 99% sure it is the rear end. I have the stock 10 bolt with 4.10's and they whine.

1997Redws6

Subscribed. I have a similar issue over 70 MPH with 4.10's in the 10 bolt. I don't believe it's the rear end for me because it used to have this issue over 90 before putting in the 4.10's. I have read in last few days a lot about issues like this and several people have solved it by replacing the transmission Main shaft. Apparently they wear and wobble in 5th and 6th gears.

armyboyatc

iTrader: (29)

I had this same deal with mine. I had the DS balanced and it helped but didn't cure it. I checked and re checked the suspension and found nothing. I finall went and got my wheels and tires balanced and boom, vibration was gone. Do the simple cheap stuff first before you get worried and point fingers at the expensive stuff.

1997Redws6

I agree Army Boy. I don't think it's the tires though because the problem was at 90MPH until I changed the gears in the rear end, now it's at 70.

Is there any way to disconnect the driveshaft, put it in 6th gear and get it up to 70MPH? This would eliminate everything from the DS back.

armyboyatc

iTrader: (29)

Same thing I thought until I went through everything but the trans. Its worth 50 bucks to see. Prolly needs to be done anyway.