Everytime I let one of my cars sit for like a week and drive it again it seems like the tranny shift hard. I owned several 3800 series 2 cars and it the same when I let them sit. Does this happen to anybody else, why does it happen, and are their any solutions to this?

Does it shift harsh in both forward and reverse? If so a possible broken spring in the forward/reverse piston. Does it shift harsh in just 1-2, or 3-4?, does it happen all the time or just cold?

It shifts hard while in driving when its shifting.It happens all year round and generally last for a day or two then it back to normal. It happen with my 99 regal gs, my 01 bonnie se, and now the same thing happens with my 01 auroura

I would say the shift modulator needs a rebuild. Installing a shift kit generally corrects this problem, but it'* not the shift kit that'* fixing it. It'* the fact that the modulator is rebuilt. If your in need of one I have a rebuilt modulator with a shift kit installed. Just PM me for details.

Maybe a trans. flush would help...the valvebodys maybe getting gunked up and need a flush might do the trick. I use the BG flush machine and it does wonders

well when it sits for a while.. all the tranny fluid drips from the gears and such.

The EPC soleniod is a very common issue with these tranmissions. Shift accumulators are not common at all. However putting in a shift kit does help with the pressure issues from the EPC and frequently helps the problem.

Bill,

Does replacing the EPC solenoid require the pulling of the trans?

The EPC is behind the side trans pan. The trans would need to be lowered. Replacing the EPC is a easy 30 second job, getting to the EPC will take a good part of the day.

I didn't time it, but when Bonnevillian and I did his the other week, I think it took us about 2 hours to get the side pan off. We did all the soleniods and the 4th hub shaft (preventive maintenance in anything under 2003 production date)