First pass with YSI = broke 6l80 case
 

After rushing to get the Fore dual pumps installed Saturday I was able to make about 3 short pulls on the dyno Sunday before heading to a local 1/8th with friends. Didn't get past 5600 due to it being so rich with the pumps. Made 2 hits on the way to track as well to make further changes and felt it was going to be ready for a soft pass. Made my first pass only leaving at 1800rpms and it cut a personal best 1.49 60ft (best on turbo was 1.577) and right before mid track it stopped pulling and felt like the trans was slipping. I slowed down to take the turn on the shut down slowly so the front wouldn't rub and then I couldn't climb the hill and park wouldn't hold the car. Towed it back to pits then had towed back to the shop and finally had the chance to jack it up now. Looking forward to actually getting it out.

The damage

I'm using a Z06 diff for those wondering

Sounds like something internal broke and broke the case. Was the trans stock ?

I was hoping you would respond haha.

Yes stock trans with Circle D Converter.

The crack is at the top front of the trans?

Top where diff bolts to.

Impossible to say until you take it apart. I would say maybe just flex broke the case if you don't have a brace, but since you said it's slipping and won't hold I'd say caused by internal break. Maybe intermediate shaft or drum.

Let us know when you do.

Where are you located ??

It's ironic I have a brace but it's for the stock diff and not my Z06. lol.

I'll def. keep you guys updated. Hoping it didn't hurt the diff.

You could probably modify the brace to fit. Worthwhile since nobody makes one.

I'm located in Maiden, North Carolina

Miss that earlier

And yeah I can def modify the one brackets or make one. Need to make it a priority .

Just bit to far. I have a trans here I don't need and you could use the case. Might be going to SC golfing soon but it's not confirmed. Would have brought it down. Lol.

I actually have an 07 trans here so I have a backup but keep me in mind if you make the trek down. I'm not afraid to have spare parts lol.

I still have my 2.56 diff with DSS output shafts here too just in case.

Good to have spares for sure.

6l80
 

If you are any where around Richmond, NC Rick Crawford is the man for 6l80 trans.

my money on broken trany output shaft

Does he build them ? I know he is supposed to be good at tuning them.

6l80
 

I said Rick because he is in NC. Adam at ACE Performance built mine and I put 50+ runs on it last year at the track, with no problems with it. I had Adam freshen it up in January for this year. Adam and Rick are good friends and work together a lot. My car runs 5.80's@121 6l80. I know Adam has a few trans that are read to go.

:ack: I had same issue... Built 6L80... First pass 1.56 60ft, 10.24, 135mph... 2nd pass broke 6l80... Output shaft sheared off inside trans and it took out the Z06 Rear end... Car didnt wheel hop... Have your trans tune checked...