Engine/Transmission (1994 - 1998) Autotrans shifting ???

[Boosted6]

I have a 98 12v with the automatic.



My truck shifts out of first gear by 10 mph. If you are on the go pedal some. if not it will shift out below 10mph. Also it does not want to downshift, going up hills or whatever it just lugs in the gear that it is in.



Is there any way of adjusting this so it will stay a little longer in first? It sure does make it a slug to drive this way.

 

[Boosted6]

No one has an Idea on this?

 

[jtwcummins]

Sounds fairly normal to me. Best thing is turn off OD. You can increase the shift point slightly. When I had my DTT done last year Bill said diesels don't have a kickdown. By doing some power increases you can improve the drivablility alot. Timing to 15. 5* and a 3k gov kit with a few other easy mods make the problem you see less noticeable since you can run fastter with OD off. Mine defueled around 2600 rpm and was a basic dog until the TC locked and you got some speed. Seems strange to watch tack go to over 3 grand when pushing hard.

 

[Boosted6]

So there is no kick down on these transmissions?

 

[JWaters]

Sounds fairly normal to me. Best thing is turn off OD. You can increase the shift point slightly. When I had my DTT done last year Bill said diesels don't have a kickdown. By doing some power increases you can improve the drivablility alot. Timing to 15. 5* and a 3k gov kit with a few other easy mods make the problem you see less noticeable since you can run fastter with OD off. Mine defueled around 2600 rpm and was a basic dog until the TC locked and you got some speed. Seems strange to watch tack go to over 3 grand when pushing hard.

All diesels have a kick down, you must have heard incorrectly.

 

[JoeBioDiesel]

Hi Steve,

There's a kickdown cable(TV Cable). It is adjustable at the injection pump end. Push the button in (it's pretty hard to push in) and pull the outside of the cable towards the firewall. Adjust it out until it has a harsh 2-3 shift, then adjust it back in a little. That will raise the shift points as much as possible.

Joe

 

[DPS]

Thereis another way to change the min shift rpm and that is with the min TV screw on the valve body. Also you can order and aftermarket VB with heavier 1-2 and 2-3 shift springs that can be adjusted to put the shifts where ever you choose.



Josh

 

[zstroken]

The 12V use a different TV spring than the 24V since the 24V have a little more PRM. You can put a 24V Throttle Valve Spring in it to give you a few hundred more RPM during full shift. I get about a 3400-3500 RPM 1-2 full throttle shift with the spring. I pickedup 600 rpm making the change. If it is a specific shift you can change the appropriate shift valve spring. Lots can be done with the TV cable. It has zero effect on the OD and lockup shift points. Whoever said that the OD off button will effect the 1-2, 2-3 shift is incorrect. There are 4 govenor solenoid algoritims(WOT, COLD, Transfer case low range, normal) in the 2002 and older 24V. Possibly less in the 12V.