Firstgenforever

I知 new here so please tell me if I知 doing anything wrong and I will try to fix it I have a 91.5 dodge ram w250 4x4 my computer is not fixable so I am doing a computer delete I want to put a pressure switch in for overdrive will it work on a 4x4 all the stuff I see about it is for a 2wheeler and if it will work I want to put a adjustable pressure switch what kind of switch do I get thanks in advance

dguru

No difference between 2 and 4wd

cougar

Except the 4X4 shift plate and linkage is in the way. I was going to go that route but did the 47RH swap instead. I thought I could drill a hole in the plate and either screw the pressure sensor or an extension hose in. Didn't work because the linkage would get in the way. If you can find a close 90ｰ fitting to screw into the case, then space the 4X4 shift plate away, you could screw a hose on it.

peckens

I have been using a potentiometer in place of the TPS for the past 6 years.

Firstgenforever

What does that do is it a mechanical version of the tps

dguru

I have not seen a 4WD bolted together but assume that with 1/8 plastic tubing and a 90 degree1/8 pipe adapter would get to the governor port. Then mount your switch anywhere. How about inside where you can adjust easy when setting it.

I have the tubing connecting my dash Trans PR gauge on 2WD 47RH.

I have a simple 47RH board made up that uses the VSS sensor or the brake sensor on the axle but both of those don't exist on 91.5. I have a small pressure transducer that I have not tried yet because all my trucks have VSS.

peckens

This is what I used. Just adjust it to where you like the OD to engage and forget it.


write up
https://www.dieseltruckresource.com/...ce-tps-142641/

Firstgenforever

Where is the governor pressure port there is a lot of plugs in the passenger side I don稚 see anything behind the 4x4 shift plate

Firstgenforever

Also is the switch supposed to be normally open or closed I don稚 want to screw something up by hooking it up wrong

Firstgenforever

Does anybody have any input

dguru

You want the switch normally open. You want an adjustable switch point between 20 and 50 psi.

Some older air conditioner low limit switches have a screw in the middle between the terminals and can be adjusted in that range with a small flat head screwdriver. I know 1983-1993 Lincoln Town Car and Mark VII had this type of low limit switch. The connecting thread is 1/4 in JIC or flare type. Pipe adapters are available. Simply ground one side of switch and run the other terminal to transmission solenoid. Be sure transmission has 12v switched on the other wire that powers solenoid. Drive and adjust screw in CW for higher shift speed. CCW to lower shift speed. Note that Air con switches have some hysteresis so downshift out of overdrive will be about 5 mph lower than the upshift point. Depends on the switch.

Firstgenforever

Thank you I will do that and get my overdrive back 40 is really slow

BHD

I tried to run an adjustable NO switch, used for nitrous, in my Cummins RamCharger. However, the 518 I used in the swap was built for truck pulling and governor pressure is over 100 psi. So I just got an old school floor mounted dimmer switch and I shift the OD whenever I want with my left foot. My initial problem was that the trans would shift 1,2,3 and right into OD at 30 mph.

dguru

at scamazon. You can find better deal elsewhere.

You may want a toggle switch in the cab to disable overdrive while adjusting and may decide to keep it as an option.

Firstgenforever

I don稚 buy from scamazon because I have got burnt to many time I will look elsewhere thanks