Hey guys i have a built full manual 4l60 and have just changed the convertor from a 3600 to a 4200 and since this i have a soft 2/3 shift.
Had a run with WOT and the 2/3 shift belts limiter so i backed off and it completed the shift.
With the 3600 stall i always had a firm 1/2 and 2/3 shift.
What do you guys think and best action to take for a diagnosis Cheers

 

Did you change anything else during the converter swap?
Is the 1-2 shift still firm or is it noticeably different as well?
Did you check that the unit was filled properly with fluid?

 

Hey mate nah i did noting else, the 1/2 shift is still perfect and sharp. if double checked adjustment of shifter and fluid level us spot on, i even added 500ml to see if that made a difference

 

What are the Third-Exhaust, Third-Feed, and Third-Accumulator orifice sizes?
What is the Line-Pressure during the 2-3 Shift... and how well does it recover?

 

Any Check-***** omitted?

 

i have no idea mate, the box was built by a shop, what pressure should i expect on the 2/3 shift?
going to have to setup a gauge so work this one out

 

Every Builder and every 4L60E Transmission is going to differ in Line-Pressure depending on how the Transmission was Built.
However in a performance built 4L60E... the Line-pressure should at least be in the 230Psi to 245Psi Range.
...Even higher on High HP Builds (over 700 HP).

 

yeah understandable, car makes 450rwhp so id say it been built to handle 600+ ill setup a gauge and see what its doing.
i cant getvit to slip loading in 3rd so hopefully a valve body issues 🤞