Turbo 400 experts please step in....

[joespanova]

Originally Posted by Mark Ugrich

Check the vacuum at the intake as well. It’s been a while , but from my training during GM tech school, govenor pressure overcomes modulator pressure to make the shift. Someone correct me if I’m wrong, but I don’t think disconnecting the downshift solenoid will have any effect on shift timing.

Sorry for the confusion. The reference to the solenoid was about whether I can leave it disconnected and if that has any consequence . No connection to upshift timing.

[jmantle]

Originally Posted by joespanova

Sorry for the confusion. The reference to the solenoid was about whether I can leave it disconnected and if that has any consequence . No connection to upshift timing.

The solenoid will delay the upshifts past the 0 vacuum shift point. You can leave it disconnected as the line pressure is controlled by the modulator only but you will get early full throttle upshifts and no kickdown.

Jim Mantle

[Mark Yacavone]

Originally Posted by joespanova

Sorry for the confusion. The reference to the solenoid was about whether I can leave it disconnected and if that has any consequence . No connection to upshift timing.

Joe, It's hooked to a n/o switch that only passes 12v at WOT, so ,about 99 % of the time, it's not doing anything anyway. So yes , you can leave it unhooked.

[joespanova]

OK , thanks everyone for your contributions.

[ss3011]

Thinking about this a bit more . The kits you can buy just modify the secondary weights and springs of the governor . Your problem is at slower speeds that may be affected by the Primary governor weights , this is the heavier weight . I would look for a different governor that has a Lighter primary weight . Suggest you find one with a big hole drilled through the primary weight and swap it on to your existing governor . Reuse the secondary weights and springs you already have but swap on a pair of the lighter primary weights . See what the effect is to that change is . Some trans shops have used governors you may be able to purchase cheap , and maybe even the pins . We had many , many different governor weights designed , both primary and secondary . Good luck ! BTW when you adjusted the modulator , did you see any effect ?

[Mark Yacavone]

Also , you can use some T350 governor parts .Weights, springs. The top is different and the plastic gear turns the opposite way.

[joespanova]

Originally Posted by Mark Yacavone

Also , you can use some T350 governor parts .Weights, springs. The top is different and the plastic gear turns the opposite way.

OK , thanks........

[Tom Goldman]

One thing I'm surprised no one has mentioned is that most OE vacuum modulator feed lines have a restriction ,usually a crimped area in the tube to help regulate the speed in which the modulator responds to throttle changes .
Also , if you are using the short , small 2" diameter modulator , There are many different spring calibrations for different applications identified by the color stripes ,usually black ,white ,red , red-red ,red-black are common identifiers .
Each one has a different spring rating ,the external adjustment only addresses the range of that particular spring.

[joespanova]

Originally Posted by ss3011

Thinking about this a bit more . The kits you can buy just modify the secondary weights and springs of the governor . Your problem is at slower speeds that may be affected by the Primary governor weights , this is the heavier weight . I would look for a different governor that has a Lighter primary weight . Suggest you find one with a big hole drilled through the primary weight and swap it on to your existing governor . Reuse the secondary weights and springs you already have but swap on a pair of the lighter primary weights . See what the effect is to that change is . Some trans shops have used governors you may be able to purchase cheap , and maybe even the pins . We had many , many different governor weights designed , both primary and secondary . Good luck ! BTW when you adjusted the modulator , did you see any effect ?

I took it out for a test drive after running the screw in a little further.no change , at least nothing noticeable . I'll spend time with the governor as you suggest , however I don't want to change the way it acts under full throttle , now. I can see this is going to require a fair amount of trial and error.........in other words a PITA. But , I'll do it none the less.
Perhaps I should just consider a 4L80E and be done with it.