04 sierra denali

headers,exhausts, intake,100shot, 3000 stall.

Trans broke 6 hrs after installation
10 months later at 10,000 miles

3 passes down the strip with nitrous after the 1st rebuild
and its mostly only drivin on the weekends. No more track passes

1st time fixed under warranty (labor+clean convertor cost me)
2nd time builder says no warranty (above still costing me )

I put my stock one back in and its holding up just fine. Shouldn't my builder fix this for me or are 4l60's just that bad. Truck has 40,000 miles 30,000 on the stock tranny.

 

If he promised it would hold up, yes he should fix it but probably won't. Call Chuck @ FLT and discuss a built 4L60E or a 4L80 conversion. He will HONESTLY tell you what he thinks you will need based upon your HP desires and he will STAND BUY whatever he sells you. Quite a few here have done conversions to 4L80's too so do some searching.

 

if you don't have some kind of written guarantee that covers racing/nitrous from the builder you're screwed. 4L60E=JUNK no matter who builds it.