NEW MEMBER SO ANY HELP WOULD BE GREAT. CHANGED OVER MY 85 Z28 FROM AUTO TO A T5 WC, NEW UMI TRANS MOUNT AND TORQUE ARM, NEW U JOINTS ON DRIVE SHAFT, BAD VIBRATION 1, 2 ,3 GEARS , PINION IS CORRECT , CAR IS UP ON JACK STANDS AGAIN CANT FIGURE IT OUT ???

 

What are you using for a trans mount?

Did you install a new pilot bushing?

 

NEW UMI TRANS MOUNT AND NEW PILOT BUSHING

 

Step into the 21st Century d00d.

If I could read your post, I could and would help you, but I'm not going to wade through a bunch of .... that.

 

ok, any sugestions?

 

Looking for some more info. Can you give a list of what parts you used?

New flywheel and clutch?

You said new UMI trans mount? I did not know they made the mount I thought it was just a cross member.

When does the vibration happen? At speed? All the time?

 

vibration is all the time < as soon as its put in gear drive shaft is normal than rev it and clunk clunk clunk, hays 153t flywheel, hays street 10.5 x26 clutch ,lakewood bellhousing, stock gm fork , lakewood pilot bushing , motor is 95 lt1 from a vette, and yes umi crossmember, gm energy suspension trans mount. new u joints on driveshaft

 

If the vibe is "all the time", as in, with the motor running and the car in gear and sitting still, then start there.

NOTHING is moving at that time except for stuff bolted to the crank.

Gotta be something in front of the trans is out of balance. Flywheel, clutch, crank.

Get that fixed first, then go to work on the trans itself, then anything behind it.

 

there is no vibration with the motor running, runs fine at all rpm . olny when its in gear is there a vibration ?

 

With the car sitting still, or with it moving?

 

Have you driven the car or it just been up on the jack stands? If you get it where it is vibrating badly and you push in clutch is the vibration still there? What about if you put it in neutral?

Have you tried a different D Shaft?

 

test drove the car a few times, at low speed vibration is worse , just sitting in neutral its fine with motor running no vibration at all, olny when i put it in gear i can feel it right away on the road , car is back up on jack stands = still vibration, so now i pulled the tranny back out, put the agignment tool back in clutch everything ligns up, both u joints were replaced after i pulled the auto tranny out ?

 

Did you torque the flywheel and pressure plate bolts to spec?

 

yes torqued to spec.

 

If you are using a poly mount you may want to try a rubber version.

 

Ok, so if you are going 55 does it vibrate? If you push in clutch what happens? If you put it in neutral what happens?

I would have u Joints and D shaft checked again and make sure it is balanced, I had this issue D Shaft was bent and also my Center Force clutch was messed up, New Clutch and Aluminum Fly wheel car is smooth now.

 

A driveshaft vibration would only get worse as you increase in speed, the OP said it smoothed out as he increased in speed.

 

I missed that part, We need more details, as of now I am leaning toward clutch issue.

 

If you replaced the u-joints yourself,
Put the car on 4 jackstands, the rear ones under the rear axle.

Have our helper driver put it in gear and run it. If you have a visible irregularity in the rotation of the driveline:

Drop it off with a driveline place and ask if it's reasonably well installed / balanced.

First time I installed new u-joints, they were off to the side a bit, although all c-clips went in fine.

You will also need to potentially troubleshoot driveline angles & vibration from a new poly trans. mount. Those will be more prevalent in the 50-80mph range, however.

 

Since the poly mount can be an issue, I'd swap in a $7.00 OE mount to see what happens.

https://www.thirdgen.org/forums/tran...ml#post4649528

JamesC