I had lost 3rd and 4th while running80mph nothing crazy ok . So I had the trans rebuilt at a reputable transmission shop . Lasted a couple months so they said maybe the valve body so they put New clutches and New valve body also using new harness and solenoids .Lasted a couple months it done same thing lost 3+4 gear . They checked everything said all they see is clutches burnt so the tell me my cold air intake may be messing up my mass air flo reading and applying the correct pressure on the clutches because it's computer controlled so I get a grannatelle cold air mass air flow meter also had the tourqe converter tune tightened to lock soon and not float thinking maybe it was slipping the converter too much but I just lost 3 rd and 4th again any ideas what to look for help

 

2003 Silverado ss 6.0 awd 4l65e

 

has to be leaking pressure from somewhere to be burning the transmission that quick..get your tune checked out by someone reputable to make sure its not a tune issue

 

. Tune was looked over everything looked good even locked converter soon trying to help but still broke . There's no torque management it's been turned off I. At a loss need help

 

Granatelli MAF is junk. It under reports actual air flow. That's how it leans out the tune at WOT for supposed performance. Put a stock AC/Delco back on it. Just because the tune was looked over doesn't mean it's not at fault. Not every tuner knows what they are doing.

 

Have the 3rd accumulator in the case or the input drum been replaced? What are they setting clearances to on the 3-4 and are they replacing the seals on the servo, and accumulators when they go into the trans?

 

True the granatelli maf gave false reading and was causing it to lean out ! I installed the factory maf back after my tuner looked it over ! But still can figure what's causing the transmission to kill 3+4 clutches

 

I'm not sure but I will ask this time

 

When I had that issue it was 2 little O-Rings that were the wrong size put in on the valve body and was causing pressure to bleed off. I burnt up 4 transmissions like you with normal driving within a week because of this. Trans builder told me the same **** that it's the tune. Stock transmission lasted 2 years with the same tune and when I got the trans finally built is when it started to have the issues. Go to a different transmission place have it looked over completely.

 

^^^ that too!!!