I have an 05 ecsb z71 L33 my problem is after getting my trans where i want it I get a squel under full throttle up shifts on 1-2 with or without the tow haul [I have more line pressure in my performance mode] any ideas ?

 

ttt ???

 

Mine has done the same thing since my tranny was rebuilt. I'm assuming my squeal is the accessory belt slipping since it shifts so much quicker but have not been able to prove it or eliminate it. Chuck says he has NEVER hears a 4L60E squeal. I too am curious for some comments.

 

My guess would be belt squeal as well.

 

it might be the belt when the truck sits over night it squeeks at startup for a few seconds.

 

but I have read a post on hptuners about a holden with 4l60e and they said to lower the force motor table ie increase line pressure I have tried it but to no avail

 

Had the same thing happen when I upped the shift firmness and added servos. Its the belt squeeling.

 

My belt squeals also on hard shifts.

 

Well i got it. its the trans bleeding off pressure, lowered the line pressure and no more squeal .