Who else has built/tuned there own 4l60e

[CAFA_TF]

Hay all
curious to all others who have built and tuned there own box
Initally when i built mine i left out the return springs of the 3rd 4th clutch assem and the master over run clutch check ball
a few things i was suggested to try see what happens. Went well however 2rd 3th changed in .1 of a second carnt be good for logevity
Band slip in 4th tho is what got me - running sonax servo for 4th oversized kevlar band and Rayspestos clutch pak in 3rd 4th i still coulnt tune out the slip in 4th
I have my back up engine box in the car now while i rebuild the engine, but im curious if anyone has modified a box to counter this in tune or physicaly? though accumlators or spacerplate? power valves and a stack of line pressure? or does eveyrone just ignore it
:)
any convo is appreciated
cheers

[CAFA_TF]

I should point out most stock boxes have the same slip i just thought i would kill it
im going to make some more modifications one by one see what combination does it booster next and tighter band specs on servo will see how it goes will be a few months

[joecar]

The 3/4 return springs are required to help 3/4 release when downshifting to 2nd... so those aren't the cause of slipping in 4th;

is the servo pin the correct length...?

you might look into the TransGo HD2 kit.

I'm not sure, but I heard the kevlar band might not be good, but I'm not sure.

mrvedit on in the Transmission forum on ls1tech.com may have information that is more meaningful.

[joecar]

How are you measuring slip in 4th (or any gear for that matter)...?

When do you see it slip...?

[CAFA_TF]

Thanks for your response!!
Measuring slip via shift time and shift time error getting about 1.1 shift times into 4th even with 600 commanded line pressure it limits the slip to about .8 have it down low at half shifts top end when down the quarter mile as well its just there all the time i and the engien has less then 350kw NA at the fly
I have my back up engine and box in the car at the mo, never been striped down in the car has the same slip
Servo is in specs but up the other end i think it was 0.25 to 0.75 travel? and im up near .6 .(at work dont have numbers )
you are prob have the right idea just shiftkit the whole thing all ill grab a HD2 kit
yeah so far the oversize Kevlar band really hasn't made a notable difference at all