Transmission, Automatic

Easy Mod for Firmer Shifts

#1
I got quite a few responses to my post about adjusting the auto transmission shift firmness. Here is the procedure. David Roberts taught me this and said it has no adverse effects to durability; it is similar to what alot of Japanese cars do with their 2 shift programs, firm and soft.

Under the rear of the car, you will find the transmission. Hopefully you already knew this. Just kidding. Anyway, on the driver's side up near the linkage is a round part with about a dime sized black cover on the
middle. On my car the round part is green and the dime sized cover on it is black. This is the vacuum regulator which adjusts firmness of the shifts based on vacuum. You will see a vacuum line running into the top of the regulator. The quick and dirty way to do the adjustment is to pull this line off. This will give you full firmness on the shifts. That’s what I did and it feels great! In my opinion, it’s not much harsher but much crisper. Make sure you drive a bit until the tranny is warm to judge it because its somewhat harsher while its cold. Also MAKE SURE YOU PLUG THE VACUUM LINE WITH SOMETHING! You don't want it sucking up dirt. I just used a screw that fit firmly.

If you don't want full firm, you can adjust for something in between. Pull that little dime sized cover off and there should be a little handle that pops out. If you turn the handle clockwise, you get firmer. Counterclockwise, you guessed it - softer. I think that’s correct; I could be backwards as I said I didn't bother to do this. I personally think it feels great on full firm. Hope you all can use this.

#2
The more correct way to modify shift firmness is with a valve body modification kit. The instructions from the ones we use here in the UK are on my (unreliable) FTP server. It's on my home machine, and is *not* always working...
ftp://195.44.34.159/shift_mod.zip
Chris Wilson