Review on 🚗 B&M 70239 Shift Improver Kit: Enhance Your Automatic Transmission Performance by Jason Caldwell

I installed this kit on my truck (91 GMC Sierra C1500 2wd) in 2012. It took a day and an evening when a friend helped me. We had a truck on jack stands in our driveway. I used to install one of these in a friend's truck, but wanted to improve my truck's sluggish shifting. I used parts of the street stripe from Stage 2. Wow. It shifts so hard from 1st to 2nd that the tires bark, which is what I wanted, like 3/4 or more throttle, but since you take out the 1-2 battery spring and replace it with shims, you're going to shift very hard . In fact, it shifts too much. Now I like hard shifting and I put shift kits or valve bodies in all my automatic cars, but this is just ridiculous. With very light throttle it still shifts way too much. I usually let off the gas at around 12-15mph so it can shift into 2nd gear as smoothly as possible. It switches too much causing my truck to sometimes jump from OD to N from 1-2 shifts when the switch is on OD. The 2-3 shift is great and the 3 OD shift is good too. It's just that layer 1-2 is too heavy. People ask me what's wrong with my transmission when they first get in my truck. I have to tell you that I installed a replacement kit on this truck. I'll try to find the box, remove the battery plunger assembly and replace them with stage 1 RV/heavy duty springs. Definitely need a spring to cushion the shift as the spacer won't dampen anything and will cut into the gearing. I tow car trailers and boats with my truck so I also added a huge transmission cooler when I made the shifter kit and it towed great and kept transmission temps nice and low. I will be adding a Corvette servo soon.