I have a 1997 Buick Lesabre (Factory L36 motor, 4T60E trans) with just under 140,000 miles.
For the most part, the transmission behaves fine, but the shift time for the 1-2 shift takes several seconds to complete. Once it completes, it seems to engage firmly. The 2-3 is a bit slow as well, but the 3-4 shifts are perfectly fine. Downshifts are fine too. Other than that, no issues that I can notice. No transmission codes or converter lockup issues either. The first couple shifts while gently accelerating are just very slow and I am concerned with accelerated wear from clutch slipping.
Started with standard fluid and filter drop, magnet looked fairly clean. Took apart filter, usual metal specs but not bad. Used Dex 3 compatible fluid to replace pan drop loss. No change in shift quality there.
Replaced OEM vacuum modulator with aftermarket adjustable modulator, modulator is adjusted to firmest setting (screw fully turned clockwise) and still no difference.
Next step I'm thinking is a mild shift kit... I've used the transgo kit for the 65E with great results before. Will changing to stiffer accumulator piston springs give me similar results on the 60E? Transgo's 4T60E "Jr." kit doesn't look even remotely similar to what I am familiar with, so I am a bit lost.... if anyone can give me some direction on this issue, I would really appreciate it.
