Seems to have a mind of there own....

If I hold a steady throttle it will continue to climb in RPM's till it redlines..this is on first to second..if I let off around 2 and a half it will shift into second..some times it is smooth ..sometimes ..bangs..very inconsistent....What contrils the 1-2 shift
other than the valve body...What could impact the shifts this way...solenoids?

 

When the shift occors is controlled by the PCM and the main control, the PCM is reading a load table in the program, and if you ease the throttle out it's possible to run just ahead of the load table figure until the RPMS hit a hard number and the shift "drops", that's a vey simplified explanation, but it's how it works. A tuner might be able to explain it better, but there is a point when the shift must occur even if you're not at the shift point called for by the inputs coming from the TPS, the TSS and OSS, when that shift occurs, your line pressure is higher than normal in the "before shift" state ( a term our test stands use in the test report, don't know what it's called in a truck), and it drops the shift hard. I really don't think it hurts anything, and I can definitly get any truck to do it if I try. It's sort of like learning to drive around toque reduction, which I can also do, just something you can "trick" the PCM into doing to the tranny.

G

G

 

I thought my trans was doing the same as yours. With the truck in DRIVE I'd fell 3 shifts,but the 1-2 shift you had to let off the gas. When I put the gearshift in 1st and shift manually to 2nd no 2nd gear. so I guess the 3 shifts i'm felling is the converter lockup. Anyway monster box was ordered on weds.I hope I get some time next week. Anybody know the dry weight of trans. and converter.Local trans shop said 3 hundred for the install. Any tips I need to watch for with the install,does the exaust have to come down. I wonder if the install price is including the exaust removal.


If you haven't already, try shifting it manually.

 

$300 sounds pretty good for the install. I went to the local tranny shops around here and they wanted $600. I just did mine myself.

 

Mine would hold the shifts when my TPS went out. It would shift out untill 3-4,000RPMs. got a new TPS and set it and everthing was normal.

 

Guess I check the TPS voltage...

Idles fine....could have a flat spot in the wiper maybe...

Now to find the TPS voltage specs...

Gregg..when you say..The main control..you are referring to the PCM ?

Thanks..

 

Have you thought about taking it in to the dealer and having it checked out? j/k

 

I thought of that...they informed me it would be better to just wait till I get the large cash settlement then go somewhere else...snicker....

 

No, the main control is one of the 3 valve bodies. The Accumulator controls shift "feel", only thing it does. The Main control controls which gear you're in, in manual mode mostly, it sends fluid directly to the intermediate band in M2 and to the forward, coast, reverse and direct clutch in R, and to the solenoid at all times, the solenoid fires different circuits to control the automatic shifts at the right pressure, as commanded by the PCM. That's a very simplified explanation, but you get the gist.

G