"Race Built" 4L60E

Hey everyone, I already love this new thread. ;)

Anyways, I recently bought a Race Built 4L60E from TreyZ28, which I'm picking up soon, because mine was slipping at higher RPMs. I'm looking to this as a solution to my problems.

My question is, What are some important components of a 4L60E that are important to be upgraded in order to support higher Horsepower? Clutches? Synchros? Servos?

I am relatively unfamiliar with transmissions and I was wondering if someone could shed some light on this subject.

i do not believe automatics have synchros


a few of the obvious things that have to be upgraded are (more)clutches, band, sprag, etc...

heres a list of the buildsheet for my (used to be mine :() built transmission if it helps at all...


-Borg Warner Deluxe Overhaul Kit

-Alto Red Eagle 2.625" Wide Hi-perf. Band

-New GM 10-vane front pump, teflon bushing

-HD "The Beast" Sun Gear Shell

-.500" Boost Valve (higher line pressure)

-Borg Warner 29 element forward sprag

-7 clutch frictions in 3-4 pack

-Sonnax servo release check valve

-ALL sealing rings, Torrington bearings,
bushings, thrust washers, seals and
gaskets replaced. New filter

-New #716 Input Clutch Housing

-New TCC/internal wiring harness

-New GM Reverse/Input Drum

-Borg Warner Low/Reverse Roller Assembly

-Hardened Vane Pump Rings

-Reverse Input Piston modified

-Longest GM band apply pin, for minimum
servo travel

-Bonded forward/3-4/reverse pistons

-Spacer plate feed holes drilled, HD 1-2
accumulator spring. 3-4 accumulator
blocked.

All clutch packs set for minimum clearance,
electrical solenoids & manifold pressure
switch known to be good (58K mi. on them).

All hard parts hand-selected or new.

most of that would be fine for a race only unit but I find making the band to tight just burns it up(longest pin when not needed).

blocked accumulators will be ok if using a big stall but still plays hell on parts.

i also like to use a FULL set of bonded pistons. Unless using the ART CARR inputt drum. This is a nice unit with thick steel band re-enforcing the spline area. Uses aluminum CC piston. I like to use the Aluminum forward piston with aluminum CC piston.

regardless of what you put in it it will NOT live with out good programing.

I have 56K on my factory parts. I did upgrade the Sprag four years ago when I ripped the center out of a B&M converter on the first blower pass I made. Since then I have beat the hell out of the darned thing and it is still alive. ;)

Programing programing programing!!!!

Good luck!