I finished the 4l80 rebuild tonight and decided to go ahead and put the thing in. So I do and when it comes time to put the torque converter bolts in, they dont line up with the holes in the flywheel!! WTF?? 6 hole brand new GM flywheel, 6 lug Pro Yank 3400 converter.....3 of the holes are about a half a hole off the other 3 are more than a half off-like you can see the edge of the threads through the hole in the flywheel. When I ordered the converter Mike specifically asked what flywheel I was going to run and I told him a stock 6 liter flywheel. Has anybody ever ran into this? The holes in my midwest converter lined up perfect.

 

My Yank convertor lined up with no problems.Does rotating the convertor relative to the flywheel make any difference?

 

Whitt, I am looking through the hole in the flywheel on the pass side where the starter goes. As I rotate the converter every other hole is 1/2 off the others look to be more. No way would a bolt start in any of them. The converter lugs are just wrong, thats all it can be. I guess I will pull the trans tomorrow and take a look see.

 

I believe you, but check this out anyway. I hope you are wrong, for your own sake! Good luck, my fingers are crossed for ya.

https://ls1tech.com/forums/showthrea...flywheel+holes

 

That's the bolt pattern used on their 6 lug car converters. I think your gonna have to file 3 of the flywheel holes to be able to use all 6 bolts.

 

Speartech, 6 lug car pattern, huh? What flywheel do the car guys use? I could hog out 3 holes with a file pretty easy, but the other 3 are almost an entire hole off-would be a big oblong hole when done.

 

I just finished installing a Yank Extreme (6 lug) in my 91 LS1 Camaro. I had to drill the other 3 holes in the flywheel.

 

OK, thanks John. Looks like in the morning i will drop the trans and get the drill bits out! I wish I woulda checked it beforehand. But that is something that is just assumed to work.

 

NO NO NO Don't you do it, you will be in for a world of hurt when you slam in to it for a power take off, their is a very good reason why all of the holes must line up. this is a place where the right parts really matter and a balance at high RPM's under heavy amounts of torque count.

take the converter back and tell them how far off the holes are they must have given you the wrong one.

if you have too take the vin off of the block if the motor has been replaced not the dash so it can be matched up.

 

Yeah, you really would have thought it would have been designed for the 4L80E bolt pattern. I don't know if that's a screw up or not on Yanks part.