I was wondering what upgrades are available for the 4l80e transmission found on late model Chevrolet / GMC pickups. I have an '04, and would like to do something about the harsh 1-2 shift. I though I read about a servo upgrade somewhere, but I can't seem to find it. Any help would be appreciated.
Try switching to a high quality synthetic fluid. You want to soften the shift? Most upgrades will firm it up.
I understand the need for a firm shift, but the one in my 4l80e is down right harsh. As soon as I can, I am going to change the fluid over to Mobil One Fully Synthetic ATF. I used this for over 100,000 miles on my previous rig. That stuff is really great for towing, it doesn't seem to break down as fast as conventional ATF. I guess I was wondering if upgrading the servo would cure the problem, while still allowing the trans to work as intended. (for the record, the 2-3 shift performs as expected. The 1-2 shift is fine under load, it is just really harsh when the truck is empty.)
4l80 upgrades your 4l80e shift firmness is controled by the pcm. you will need to reprogram it to shift softer. some of the computer upgrades also modify shift firmness (to help the trans live) but there are a lot of great programs out now that will let you and your laptop do anything you want to. (good or bad). check out ls1 edit or hp tuners. i hope this helps. eldogg queen city speed
