99 Monte - Weird transmission shifts

[Spanky]

1st shift is at about 15mph, 2nd shift is at about 25mph, but the next shift isn't until around 40mph and about a second later the lockup kicks in. Sometimes if I turn on max A/C the shift points seem normal 15-25-35 and lockup around 40.. Problem is the late last shift and lockup quickly after.. Any suggestions appreciated.

[Addicted To Boost]

That is normal operation for these transmissions. Depending on gearing, most don't shift into 4th until 40 or 45 mph.

[RobertISaar]

being a 99, could be a 60 vs a 65 too, both of which operate a bit differently.