R-Steffen 99ls1

So just got my car dynoed and found a problem. The trans vibrates really bad and my speedometer freaks out at about 80 under a load. What's the problem, I wanna learn about trans.

RevGTO

iTrader: (12)

Please knock it off with posting a new thread every two minutes. Have some patience and maybe somebody will respond. PITA for me to have to delete your eight other threads now.

mrvedit

It sounds like your trans output shaft is very loose due to a very worn bushing and/or internal wear. This is causing your driveshaft to wobble creating the vibration and the speed sensor on the output shaft to misread.
If true, it will require a complete trans rebuild. If true, your car should be driven no further than a repair shop as strong driveshaft vibration can snap a u-joint causing severe damage to the car.

The full diagnosis will require removing the driveshaft and then the tailshaft to evaluate just how loose the output shaft is.

As RevGTO stated, stay on this thread for the entire issue. For one thing, people are more likely to contribute to an existing thread instead of a brand new one.

R-Steffen 99ls1

Thanks for the input. My phone was messing up and kept telling it was a duplicate thread so I thought they weren't posting. My mistake.

01ssreda4

iTrader: (96)

How did you pinpoint this down to the trans? How do you know its not somewhere else in the driveline? Horse goes before the carriage fella.

R-Steffen 99ls1

The only thin that led me to the trans is because at about 110mph it will slip completely under full throttle. It happened to me last Sunday in a race.

mrvedit

This sounds like a different problem from your first post.
As 01ssreda4 suggested, most vibration problems are due to the driveshaft/drivetrain and not the trans. I only mentioned the output shaft because your speedometer is erratic, but a combination of wobbly driveshaft and bad VSS connections is another possibility.

Slipping is a different problem. What gear was slipping?
As you probably know these transmissions have a notorious problem with the 3/4 clutch slipping. This is usually noticed in 3rd gear. If only 4th gear is slipping and you race in 4th gear, you should consider a 4th gear billet servo piston.