Garverless

1994 cummins with auto this truck has to be flat to the floor at 55 to shift into overdrive. Changed fluid and filter no difference.any Ideas??

richard

The first 2 things that you shoud check are the tv cable adjustment and the TPS. both have control over the 3-4 shift

PumpDaddy

Mine did and still does the same thing, afte $1800.00 for a rebuilt tranny, just maybe not so bad. It won't shift into 4th,and sometimes when it does, it'll shift back to 3rd, then back to 4th. When it shifts into 3rd, if you STOMP it, it'll shift back to 4th, at about 55-58 mph. Bushy says he has printable text file that walks "Dummies" like me thru the procedure to check and/or correct the TPS. I've e-mailed him my e-mail address, but haven't gotten it yet.

Bushy

I think you have it now PumpDaddy.... if anyone else needs my checklist/method for the TPS on 1st Gens, let me know.
BTW, the process is pretty well the same for 2nd Gens too, with the TPS affecting the 3-4,4-3 shift. However, on the 2nd Gens when the truck goes from 2nd to 3rd, it doesn't go straight from 2-3.... It shifts like this (I think) 1-2-1/3-4.
The tranny actually drops from 2nd to 1st (before going to 3rd)then up to 3rd, then 4th. Please confirm that with Bill K before you take it as gospel...
The things that can make your tranny shift wierd are the TPS, the throttle vavle cable adjustment, and the speed sensor on the tranny (or transfer case if it's a 4X4) the speed gear on the inside of the speed sensor assembly, and the "drive shaft" of the assembly. The "drive shaft" is a small square shaft or post that connects the drive gear and the rest of the sensor assembly.
Bob.

Garverless

Bushy could you send me the checklist <br>Garverless@aol.com<br>Thanks

Garverless

thanks guys i will try some of this stuff this weekend when i can steal my truck back from my little brother and will let you know what happens!!!!

New_Dog93

Sounds like I might have a similar issue with the O/D in my 93 d250. It was fine earlier today going into the city. Pulled 130km/hr + in O/D.... Dropped off my kid and hit the highway again..... NO overdrive! I checked the fluid level and topped it up, checked for loose wires etc.... nothing! Bushy, could you send me your checklist for the TPS? Anything is worth looking at before taking it to a tranny shop!

cheers,

Dave

J BODY

Poor running engine (lack of power) can cause this too. Fuel psi to the injection pump within spec??

Swarthy Dago

Boy this is the day for it. I put on that new overkill exhaust manifold Lary was selling for the site here and now my trans is acting real strange. Before the install the Torq. C would hook up, the turbo would light and the truck would just surge and pull hard, over drive back and forth no problem. Now after the install, I've lost 10 lbs of boost from 30 lbs max, the torq. c just kinda slips and won't lock up hardly ever, and in o.d. it sometimes goes in and out, in and out. First I'm going to ck all gaskets for leaks, but I could use a copy of the checklist too if you wouldn't mind.