Modded 4l60e shift issues
So I guess the best thing to tell you guys first is whats in this transmission:
2000 4l60e
9.5" Yank 3600 Converter
Sonnax Smart Shell
5 Pinion Front and Rear Planets
Kevlar Wide 2-4 Band
Sonnax 2nd Gear Super Servo
Sonnax 4th Gear Super Servo
Sonnax HD 2-3 Shift Valve (over run clutches on in D3)
Sonnax Performance Pack (Accumulator Springs and Pinless Pistons and Servo Check Valve)
All Clutches are Raybestos Stage 1's with kolenes except 3-4
3-4 Clutches are Raybestos Blue Hi-Energys @ .050" clearance
This transmission has taken tons of abuse and held up well. When I first built it I was very satisfied but it never really shifted as firm as I wanted. So I drilled the separator plate and now the shifts are all f'd up haha.
Feed holes which worked but weren't firm enough:
2nd: .093
3rd: .093
4th: .093
Here is what I drilled them to with hopes of tire barking shifts:
2nd: .125
3rd: .125
4th: .125
So now it shifts crisp and firm in all gears but only at 1/4 throttle. As soon as I go into 1/2 or more throttle the shifts become slow and soft. So tell me why drilling the plate resulted in firm shifts only at part throttle?
NOTE: This trans has the Sonnax check valve which I drilled the orfice to .125" per instructions.
EDIT: Forgot to add it also has transgo Hi RPM 3-4 release springs.
Fluid level is OK???? I fill too the Max Hot mark with the unit Cold. 1/2 Quart over.
Did you install the "Pump Parts"?? Boost Valve & Primer Spring.
What shape was the Pump in??
What pan are you running? Good/Correct Filter installed? I use OEM SPX/Filtran.
Data Log the EPC, TPS, MAP, MAF.
Fluid level is OK???? I fill too the Max Hot mark with the unit Cold. 1/2 Quart over.
Did you install the "Pump Parts"?? Boost Valve & Primer Spring.
What shape was the Pump in??
What pan are you running? Good/Correct Filter installed? I use OEM SPX/Filtran.
Data Log the EPC, TPS, MAP, MAF.
The pump has the .490 boost valve and spring, heavy pump slide spring.
Pump is in excellent shape.
The pan is a deep pan from trick flow, comes with an aluminum extension tube to run stock filter which is brand new. Every time i pull the trans i replace the filter.
I am suspecting the tune has some issue or the EPC is fouled up.
Also the truck has a speed density tune on it.
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Especially when a newly built trans (whether by the owner or a shop) is acting up.
Clinebarger and PBA (both pros) have you well covered.
PBA, I was thinking when I tore into the trans this next time taking the input drum and removing the input shaft to apply some sleeve retainer. I already have the input drum reinforcement kit from sonnax.
What are your thoughts on the Smart-Tech Input Drum? I like the thought of more clutches with thicker steels to dissipate heat, but I read in another thread where you said the friction materials ability to retain fluid is what keeps the clutch pack cooled down and also you said that coning of the clutch pack isn't as bad as everyone makes it out to be. Thoughts?










