It will depend on rear gear, torque converter, modulator setting, and even to some degree, the governor, believe it or not. In general, minimum throttle shift points should be, 1-2, 9-12 MPH, 2-3, 20-25 MPH. The more throttle you give it, the higher it should extend the shifts. With a looser converter, the transmission can shift lower. I wouldn't characterize my current converter as overly loose, but it doesn't give a lot of resistance when you slowly open the throttle. As a result, my shift points are about 10 MPH and about 27 MPH. With my switch pitch in low stall, I found it really easy to extend the shift points by rolling into the throttle. I could easily keep the car in 1st gear, and bark the tires on the 1-2 shift. I can't do that with this converter. My guess is it doesn't drop the manifold vacuum enough to extend the shift points. At the track, I find the WOT shift points are where I need them at around 5800 RPM. Same thing applies to my kick down. Most THM 400 later valve bodies allow a part throttle "Hydraulic" kick down not involving the electric switch. With my switch pitch in low stall, I could get it to go 3-2 at around 40 MPH without much throttle. Not anymore, I really have to lay into it, to the point where the gas pedal switch does it's thing. Then the tires just go up in smoke. With a THM350, the kick down (detent) cable, or lack there of, will also make a difference in part throttle and WOT shift points.
my tranny used to shift at speeds similar to yours. However, about 6 weeks ago, the 2-3 changed such that it may not shift until 34-43 mph and seems to shift a bit harder. Who knows?
@LARRY70GS I shift into 3rd around 40 mph (TH350) and I have to give it much more gas. I have changed the modulator, but to no avail. Should I loosen or tighten the screw on the adjustable modulator. I am considering changing the torque convertor.
Turning the adjustment in makes the shifts later. Turning the screw out makes the shifts earlier. This applies to the small brass red stripe modulators, they are meant to be adjustable. The stock modulators are not. Are you adjusting a stock type unit?
@LARRY70GS it is an aftermarket B&M adjustable modulator. Is it possible that engine modifications are not mating with the transmission. My mods in my signature. I think it may be time to adjust the shift points and get a new Torque converter. I am just learning about how the TH350 works
The modulator can adjust for lower vacuum with the adjustment screw. You have a mild engine, should have enough vacuum. I would try playing with the governor weights and springs.
