Ok so basically I have an 84' with an LT1/T-56. I used the conversion bracket from Pro Sftreet Customs (Bought in late 2010) and I have noticed the shifter lifting under acceleration. Last summer I tried to tighten both front C beam bolts and had to replace one as it stripped out. I got a new bolt from fastenall and torqued the crap out of it. The lift got a little better but it still lifts quite a bit. (The lift pushes up hard on my center console and makes it creak and pop under the strain). The instructions for the adaptor bracket tell you to elongate the holes on the C-beam by 3/4" towards the rear of the car. Could this be causing that much of an issue? I have been tempted to get the C-beam plates that everyone loves but the torque specs seem to be too low to stop the lift as I torqued mine down quite a bit and it still lifts. (The bolt holes in the bracket itself also came elongated) I'm using the original auto C-beam that came on the car. Can I use the D44 C-beam as I think they are 1" shorter?

I feel like the movement is because I elongated the holes and I can't get enough clamping force to stop the movement between the parts. Most people I have seen that used this bracket don't seem to have issues.

I decided to start thinking about fixes to this as it's winter here in NY and the car is put away. I did 3.73's last summer and those made the movement even worse so I decided it's time to figure this out. Anyone have a similar issue or a fix?

 

Here's a link to the bracket. (Old thread from someone trying to sell one)

https://www.corvetteforum.com/forums...m-adapter.html

 

I'd throw a go pro under there and see what's going on. I have no doubt that the front of the C-beam isn't rigidly affixed to the adaptor plate, but it would be nice to SEE and know if it's vertical slop or longitudinal slop.

What tq did you apply to those bolts? It doesn't look like the bolt holes on the adapter go all the way through. (?)


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The bolt holes go all the way through. Basically you clamp around the bracket instead of the tail shaft of a 700r4 or ZF6. I'm not sure the exact torque but I put a 1/2" breaker bar and torqued it as much as I could. (Shorter breaker bar but still) yea a camera under would be a good idea. I was tempted to jack up the tail of the tranny to see where the slop is. Like push the tail of the tranny up slowly and watch for movement. I'm not sure how else to fix the problem other that getting another c beam and trying again. Maybe I can also make my own c-beam plates too.

I also see in the instructions that it says you might have to put a washer in between the bracket and the c-beam if it has play. Maybe I'm not compressing the c-beam enough to clamp the bracket hard enough to stop the slop... I'll have to find out exactly where the play is and go from there. I just wasn't sure if anyone else has had this problem before and was able to fix it.

 

My (4+3) c-beam fit tight to the bracket, no spacer washers needed. I didn't have to hammer it on, but it was not loose. My bracket came undrilled so I drilled it without oval shaped holes.

 

From what I have read thats the way they come now. I wonder if they had issues with the slotted holes. Did the holes line up well on the bracket? I wonder if I can get away with using a D44 Cbeam. I just don't really want to change it, I guess I'll have to see where the play is before doing anything.

 

Mine is a late version. I put everything in place and C-clamped it for drilling the holes. I used a hole saw to make 2 holes in the transmission tunnel for torquing those bolts. I agree, find where its moving before you swap any parts.

 

Are batwing bushings worn out allowing diff to rotate?

 

I'm not sure how that could cause the shifter to raise (Am I missing something) but no they are pretty solid. I just had the diff out last summer.

 

Have you every noticed a engine "torque" over under load ? The diff can do the same thing. Since you had batwing out it seems you would have noticed their condition. Get the Go-Pro and see whats moving.

 

Yea that seems to be the best idea at the moment. Thanks for the reply.

 

Are your motor mounts tight? Just a thought.

 

Yea the engine barely moves when it's revved.