Hey there everyone.

I had an incident coming back from my favorite surf spot-blew a trans cooler line. Didn't know it until the trans started shifting from OD to third and losing power transfer. I taped up the leak as best I could and added the trans fluid I had on board-I had to get to a spot to park the truck overnight. So it's very possible I did some damage to the OD section. The weird part is that the OD was performing as normal for some time after the incident (1 month at least) and now it has the no od shift issue. Everything else is fine. good shifting up to 3rd, and TC lockup is fine.

The vehicle is a 2003 DRW Cummins. I have checked the brown wire at the trans which is the OD solenoid low active input wire from the PCM, and it is going low to activate the solenoid.

I pressure checked the trans as per the manual. The line pressure is fine. When shifting into overdrive the OD pressure goes from 0 up to about 15 psi. Wondering if this type of behavior could still be an OD solenoid not working properly? Do the solenoids 'click' when you manually engage them? I was under the truck with key on engine off so I could hear. The OD solenoid had no click when the brown wire was manually grounded. I tried the OR/B for the TC Lockup solenoid and I could swear that I heard it click once, but I couldn't get it to repeat. Weird.

If I have a internal OD issue, is it more likely the piston seal or the OD clutches? Every other gear works fine so the 'direct' clutches are probably fine right? Wondering if I should order OD clutches/steels and a piston seal to try to get a quick turnaround on this sucker once I pull it apart?

Any advice?

Thanks all,

Chay Foss