'92 Tranny Help

[altec27]

My explorer is driving fine in gears 1-3 and R, but it won't shift up into 4th gear. Do I need a completely new tranny? Or, is there something else that might be wrong with it. Any imput would be greatly appreciated.

 

[Glacier991]

The 4th gear is commanded by the computer, which activates a solenoid inside the transmission in the valve body. More often than not a lack of 4th can be due to some problem either in that circuit electrically, or because your model used a solenoid with a very fine screen on it, and the screen is plugged. All of these things can be investigated and repaired without removing the transmission.

The other, more sinister possibility, is that something in your OD section of the transmission has failed. (4th is nothing more than the OD coming into play on this transmission.)

 

[altec27]

I had the solenoid looked at and it looked ok. So, the problem looks like it is something in the transmission. If that's the case am I going to be able to drive in gears 1-3 on a consistant basis, or is the entire tranny shot for good? Also, would you recommend trying to replace the specific part or should I replace the transmission as a whole? Thanks.

 

[Glacier991]

Well wait... it could still be electrical in nature, or it could be the va;ve body needs to be rebuilt. I try and exhaust every possibility before I remove a trannie. If you do those things and still have the problem, then you are faced with removing the trannie and inspecting the OD section - which, good news, is the first thign inside once you remove the pump.

Continue to drive? Hmmm if the problem IS electrical or VB, sure go ahead. If the OD inside is trashed, you may be contaminating the rest of the trannie.

Me, I'd investigate the electrical and rebuild the VB.... if that didn't work THEN I'd drop the trannie. Hmmm now, assuming we have the trannie out... rebuild everything or just fix the OD? Your call.

 

[altec27]

First of all thanks for all your help, it's helped me get an understanding of what's going on.

I think I've exausted all the options except trying to fix the transmission. I got a quote on a full transmission (around 1400), but I haven't been able to find one for just the OD.

Do you have any idea how much replacing just the OD would cost?

 

[hermitrl]

Have you checked the VSS? speed sensor? IT is attached to the speedometer. Mine broke and the truck had no overdrive at all.