Help me Diagnose my transmission problem

300000 and counting · Jun 9, 2016

I have a 2009 F350 4x4, and I'm having tranny problems and I just want to make sure the tranny is actually toast before I spend $5000-$6000 on one.

Day 1: Transmission fell out of 5th gear and wouldn't go back into 5th but would go in reverse and 1st through 4th, it would also lock the TQ in 4th. As soon as it fell out of gear I got two codes: P0766 and P2703.

Day 2,3: When I started my truck the wrench on my dash would be gone, but the CEL would be on. The truck would shift up to 4th without locking the TQ but would fall out of 4th until the wrench light came back on. Reverse would work on and off but if I put the truck in low range then in reverse it will back up every time.

Day 4 (Today): Morning started out like day 2 and 3, I went to the gas station turned the truck off, the wrench went away like normal, but this time it didn't come back on and it would shift into 4th and 5th and the TQ would lock in both gears, this lasted about 10 miles until I came to a stop and started driving again and the truck went back to only going in 1st to 4th no TQ lock. When I got to work the reverse barely worked enough to get me back in my spot in high range.

I'm working out of town so I haven't been able to pull the pan off yet, but the fluid levels are normal and the operating temps are normal. It does seem to take an extra second to shift into 1st through 4th but I also switched my H&S to stock so that could be the reason. Any help would be great, I'm probably going to need to get this figured out by tomorrow so I can use my truck asap.

Mark Kovalsky · Jun 9, 2016

P0766 means shift solenoid "D" is stuck. P2703 means friction element "D" didn't apply when it should. That code is a result of the first code. Fix that one and both codes will go away. Since you had at least one drive where it seems to have worked, I think this can be saved.

Drain the fluid in the pan. Refill. Drive for a day or so, and do it again. Then once more. That should fix it. If not, you'll have to replace shift solenoid "D."

Of course, you could replace the trans. That will include a new shift solenoid, so your problem will go away.

300000 and counting · Jun 9, 2016

Is the fluid to "dirty" to function properly? How difficult is it to replace shift solenoid "D"? And will it hurt to drive it 160 miles without it being fixed?

sootie · Jun 9, 2016

its about a 30 min job max to change the solenoid. all you need is a socket for the pan bolts and an o-ring pick for the c-clip that holds the solenoid in. Your sticky solenoid could be caused by debris in the oil. That can mean that the is clutch material floating around which may be an indicator of advanced clutch wear...

Mark Kovalsky · Jun 9, 2016

300 said:
Is the fluid to "dirty" to function properly?

The solenoids are VERY susceptible to very fine particles in the fluid. Old fluid can have this.

300 said:
How difficult is it to replace shift solenoid "D"?

Not very difficult.

300 said:
And will it hurt to drive it 160 miles without it being fixed?

I wouldn't recommend it. The debris in the fluid can cause other solenoids to stick, too.

300000 and counting · Jun 9, 2016

I ordered Solenoid it will be here Saturday; I'm going to change the fluid tonight, drive to work tomorrow, change it at work again, and the drive the 160 miles home with that fluid in it and when I get home I'm going to change the fluid/ filters/ solenoid and hope for the best.

300000 and counting · Jun 10, 2016

Mark Kovalsky said:
P0766 means shift solenoid "D" is stuck. P2703 means friction element "D" didn't apply when it should. That code is a result of the first code. Fix that one and both codes will go away. Since you had at least one drive where it seems to have worked, I think this can be saved.

Drain the fluid in the pan. Refill. Drive for a day or so, and do it again. Then once more. That should fix it. If not, you'll have to replace shift solenoid "D."

Of course, you could replace the trans. That will include a new shift solenoid, so your problem will go away.

I drained the fluid drove 15 miles and drained it again, it was pretty dark but there wasn't any material on the plug. My solenoid will be here today, I hope that fixes it. What fulid should I put in it when I do the soleniod? And if I can't get motorcraft filters is there a different filters I should get or avoid.

Mark Kovalsky · Jun 11, 2016

Use either MERCON SP or MERCON LV fluid.

Zmann · Jun 11, 2016

I would hit a Ford dealer for the filter but the last Fram I looked at before I bought was identical markings and all
I would not use any other filter than one Made by an OEM supplier so thats why I was comparing so closely

My local O'Rileys charges over 7 bucks a QT for LV so I order my fluid from Sunrise at a deep discount

300000 and counting · Jun 11, 2016

Well I changed the solenoid, put oem filters in it and Valvoline Mercon LV in it and nothing changed, it also seems like 4th is slipping a little too. I guess I'm gonna have a trans put in it.