My '90 F-150 (302) has an AOD and 150k mi on it. I've only had the truck for 6mos, so I'm not completely sure of the tranny mileage. Assuming it has 150k on it withou any rebuilds or overhauls, is installing a shift kit in it a risk, or would that tend to prolong the life on the tranny even further? I wouldn't be looking for a barking the 1-2 and 2-3 every time level kit, but just a little firmer shifts in everyday driving.

Wade

 

I have always heard that a shift kit will extend a transmissions life because it reduces cluth slippage = heat and heat is the worst enemy. I would ge ta TransGo and install it on Level 1. I just got mine in and I am going to install it on Saturday. Ill tell you how it goes.

 

Mine had over a 100k when I installed a superior hd kit, I run it on level 2, truck has 300k on it now, never been worked on since I installed the kit. When I installed my kit I also replaced servos, and upgraded the clutch pac, factory AOD has 4 clutch discs alows a bit of slipping even with a shift kit so I upgraded to an 8disc clutch pac and some other items. Fords, particularly mustangs are bad about busting the shift sprag if you're in od and punch it the tranny sometimes goes straight to 2nd from od and busts the sprag, they are inexpensive to get a good one and install if you're already into the tranny.
If you just want to firm it up a little and not wanting to bark the tires, a superchip may be what you want, $250 for our trucks plus you get a little more go to boot