Hey guys... Looking for some insight on what I did wrong. Did a full rebuild on a buddies 4l60e out of his 02 Silverado. Everything works great until it hits 4th gear. When it hits 4th something drags horribly. 1st-3rd are great... I'm wondering if I mis-stacked the overrun clutches or something. Any ideas to look out for when I get this thing back out?

 

Stock rebuild or upgrades while you were in there??

 

Mainly a stock rebuild. Upgrades include vette servo, transgo spacer plate with no hole size changes, pinless 1-2, 3-4, and forward accumulators, sonnax pump slide spring, and a sonnax pump pressure spring. All the clutches are bw he with new steels back to the factory stack numbers. Rebuilt it cause he broke the sunshell towing with it. Before that it worked just fine.

 

What kind of noise does it make, or does it just feel like its dragging??

 

Zero noise that I can hear; Truck has an exhaust system. Just a huge drag. Keep adding throttle and the truck keeps slowing down until it down shifts to 3rd gear. Can disable tcc or enable it and changes nothing. All commands in the scan tool look normal with no codes. Kinda has me stumped on what I did. Not the first 4l60E I've redone. Never ran into this problem before though.

 

What was clearance on the 3-4??

 

Came in around .068". Built it up with factory stack up numbers with bw he clutches. Doesn't race his truck so I didn't make it any tighter. On performance 3-4 setups I try and hit .035". Shift timing on a 2-3 shift was around .3 seconds on the scan tool.

 

Also during assembly air checked all clutches. All engaged and released as they should.

 

Im sure you checked all the valves in the valve body! But almost sounds like 4th is either slipping or not fully engaging!!

 

If it was slipping I feel like I would be getting rpm flare with the more throttle I apply. Rpms hold steady with the gear, no flares, truck decelerates no matter how much throttle given until you reach the point it down shifts to 3rd. Also checked the vb during teardown. All valves were in working order.