64f-85

Hi Guys,
I've been reading the posts here for a few days and I have a question about my transmission. I have a 2002 Silverado 2wd sc/sb with a Whipple-ized 5.3L and a 4L60E. I had Wester's do the PCM for me and it was a noticeable improvement in power however the shifts are nowhere near as firm as they were before the supercharger with Superchips programming. I called Wester's and he sent another PCM that shifts a little better however I think I might need to do some hardware mods. Here's what I experience... at full throttle the 1-2 shift is soft and it seems like it only stays in second for a split second and then shifts into third gear right away. Could it be that I'm making more torque than the transmission can hold and the PCM decides I need to be in third gear at that point?
I figure I should install a Transgo shift kit and a different servo but do you think these mods would help my problem?
Thanks,
Gene

ThunderZ28

iTrader: (7)

no it sounds like you have the same problem i do.
at normal throttle mine doesnt stay in second very long. its all got to do with the programming.
this is the problems with mail order pcms. if you had edit you could change it yourself. this iis what i am doing and it is a hit and miss thing. i changed my gears from 3.42 to 3.73 and edit has a hard time realizing this with the shift times. sounds like your jst gonna have to keep sending it back to westers untill he gets it right.

Flyer

iTrader: (1)

Yes .. probably so, but that isn't saying much.

No .. not exactly. The shift tables are defined by TPS (throttle position) and speed. Without a better description of what's going on there, it's hard to say what it is.

More than likely you have some slippage going on there. The shift kit will help hold that thing together a little longer. The servos are always a good idea with a shift kit since they snap the band in place with more force. The servos also create more holding power in 2nd and 4th.

I would recommend the Transgo and billet servos. Do you have a higher stall torque converter on there?

whitt1

With a supercharger you really have to be careful what mods you do,if you are running the Whipple at stock boost levels with the tuning that comes from Whipple and leave your torque management alone,you can run pretty much run just a Transgo with billet servos.If you kick up the boost and engine displacement,you probably will want to upgrade the clutches and hard parts in the transmission.If your setup is more extreme you might consider leaving off the billet servos,I found that with the billet servos at the torque levels a Magnacharger at 11lbs of boost can make you can actually break the hardened transmission parts.

64f-85

Hi Guys,
Thanks for the advice. I think I figured out what the problem is with my transmission. After reading another thread someone mentioned the plastic accumulator housing can crack on a hard 1-2 shift. I have confirmed this possibility with a mechanic friend of mine so now I need a billet accumulator housing. He said it is actually a piston but is called a housing. I'll also do the Transgo kit and Vette servo at the same time. Then I'll need a set of Cal-tracs and...
Thanks,
Gene