i have a 4l60e tranny w/a shiftkit, stock converter (had it rebuilt before i even knew what a converter was, so no upgrade), the car has a 224/224 563./.563 112, and comp 918's, so we tuned it a little bit after that was put in, mostly tranny stuff, the shift rpm is 6350, with a 6500 redline, when we first tuned it, it bounced of the limiter like crazy until we had to lower the mph to be met at the shift pretty low but eventually got it fixed, now heres the problem, now on the 1-2 shift it bounces off the 6500 rpm and doesnt shift, but when it downshifts (2-1-2) it does just fine. this 1-2 shift is the only time it does this, all others are fine, meaning when i punch it while im cruising it shifts fine, i dont know about from a stop to 3rd gear because i cant get out of first at WOT. is this a tuning issue or a tranny problem, (the transmission was rebuilt about 28k ago and still has the filter and fluid they put in)

 

Sounds like a tuning issue, did you add more firmness to your line pressure? Sometimes that can help our hurt.

 

no we didnt mess with the line pressure, i didnt really want to take the risk, so a re-tune is in order?

 

where are you located? hopefully it is a tuning issue.

 

Oklahoma, how come? i'm hoping so, its already been rebuilt once

 

I believe its an 98 issue. we shift off rpm and Mph. My 1-2 mph is 33 and rpm is set at 5600, even though its shifts at 6200. Keep lowering the mph or rpm. as the rpm of the motor can be a lot higher than the inputshaft rpm of the transmission, which the pcm goes by. Its not your transmission, i've delt with it forever too. When I get the tuning nailed down it shifts great.

Probably no need to change shift pressure, but i'd lower your shift adaptation to .200 It will help it to shift quicker.

PM me if you need any more help.

btw: at 28k, it could really use a filter/fluid change. I've done mine twice a year.

 

Thanks man, i'll let u know if i have any problems

 

It spins the tires all the way thru 1st, and if im going 40 and hit it they'll break loose, i'll go sideways and spin them all the way til i hit the limiter again, could the spining of the tires like that cause the motor to spin faster than the input shaft on the transmission like you said, causing it not to shift in time?

 

Ahh, If i spin bad through first it'll hit the limiter. but thats somewhat of a given, I think the PCM's reaction time is kind of slow. If you wanted to avoid this I think you'd need more of a buffer between shift point and limiter, so either lower shift speed or raise limiter, I did both

I thought you were hitting the limiter with full traction, thats all I aimed for to stop.