camar0corey

iTrader: (22)

I'm not sure what is causing it. As you climb higher than 3k rpms the car becomes shaky, you can see the shifter stick vibrating. I might try to get some film of this later today. it seems to smooth out above 5k, but honestly lately I don't really beat on the car because this issue is freaking me out.

It is a LT1, I'm running the dual disc Mcleod in it with the steel flywheel. T56 I purchased used about 3 summers ago was supposedly rebuilt to level 2 specs by this shop owner in Tampa, yeah I know, kind of big gamble there.... Driveshaft is a Denny's Nitrous Ready. 12 bolt Moser rear with Eaton posi and 4.11 gears.

I notice I get a fairly nasty vibration on deceleration also if I let the car coast. Under load or braking I do not notice this other vibration.

Any ideas?

Edit: Just thought about this, it is especially noticeable in 3rd and 4th gear, it is still there in 5th, don't know about 6th. I haven't exactly been doing any high speed runs with the thing with the way it is behaving. I think the issue is there in 1st and 2nd but it isn't as noticeable, due to the gearing maybe?

DisasterFormula

iTrader: (1)

Sounds like a trans mount if the shifter is shaking around like crazy.

BlackLS1Bird

iTrader: (2)

Check that and u-joints and driveshaft for dents, bending, and missing balancing weights. Does sound a lot like the trans mount. Shifter shouldnt move that much. Make sure the cross member is tight to the body too.

camar0corey

iTrader: (22)

Shifter mount is a three year old prothane, but I will check it out, maybe the bolt holding it to the crossmember fell out? I'll check this out.

I used blue loctite and those nuts with a bushing in them to secure the brackets on the u-joints, but I will also check those for looseness.

Also to note the faster I raise the revs the worse it gets, if I ease it up through the rpm range it isn't nearly as bad.

SuperSam

iTrader: (7)

I had the same problem w/my car. After changing literally everything out...It turned out to be the tranny.

camar0corey

iTrader: (22)

And that is what I fear.

I got under there today, I was able to tighten the crossmember bolts maybe 1/2 to 1 turn with a ratchet by hand (no cheater bar), having to really put some *** behind it. Same deal for the stud in the Prothane trans. mount. U bolts weren't loose on the U-joint in the rear. Not sure if any weights have fallen off the driveshaft or not, doesn't appear so. I can't move the driveshaft side to side or up and down, so I assume the u-joints are in decent shape.

SuperSam, what had gone wrong in the transmission?

camar0corey

iTrader: (22)

Bump!

It is less noticeable now after tightening those items up, but it is still there.

Any input on possible transmission issues? I would assume input or output shaft bearings?

Could I be lucky and it is the driveshaft? Any recommendations for places that could check and balance the driveshaft in northeastern PA?

chrysler kid

iTrader: (14)

Does it shake when you rev the car in neutral?