4L60e transmission slipping in 3rd and OD

Question for the transmission guru… I have a 2004 Yukon with stabilitrac AWD. When the transmission goes from 2nd to 3rd it slips as if there is no 3rd gear. If I start from a dead stop in D it will accelerate through 1st and 2nd gears without any slippage and when the transmission tries to shift into 3rd it acts if there is no 3rd gear (revs to moon- no forward motion). The speedometer works… and I can drive around in 1st or 2nd gear with absolutely no slipping at all. Reverse also works fine.

Am thinking it could be electrical, but not sure. What do the symptoms I described indicate? Can this be something fixable by dropping just the pan?? Could it be the 3-4 shift solenoid?? I feel comfortable changing out the solenoid, but if the 3-4 clutches done it will require dropping the tranny which I do not want to tackle.

Nope, classic 3-4 clutch failure. Sorry, but it needs to come out.


Ok, Thanks… was hoping it could be something electrical… but suppose it is actually shifting into 3rd but there is no friction once it gets there…
Rebuild est. $1350 from shop, $925 from a friend at GM who will drop it, get it rebuilt and put back in… Am thinking of spending the extra $500 and give it to someone that does the rebuilds everyday.