Tranny Issues - Cant Figure it out - 2008 2wd - P0761 & P2714

Need some guidance..



I have a 2008 2wd tundra that is pushing 200k and I have been throwing the codes P0761 and P2714. Truck drives and shifts fine 90% of the time.

I took the truck to Transmasters here in Sebastian, FL and they swapped out the solenoids but the lights and codes came right back. They said my pan looks clean and there is no shavings. The owner suggested that the valve body is worn and that's why the solenoids aren't functioning correctly and that should solve the issue, replaced the VB and a week later the codes come back. I replaced the Output speed sensor after reading that it has solved the issues for others, did not do the input sensor.

Fast forward a couple weeks, I hop in the truck to go to work and when I shift the truck into reverse it feels like it doesn't engage at all, when I step on the gas it revs up but doesn't move then suddenly it will engage and reverse.

Called another shop in town and they said the tranny is shot and needs to be rebuilt for 6k, not sure I want to go that route but looking for some advice from others who potentially had a similar issue.

Thanks

 

At a glance and only if you've ruled out a faulty connection between transmission and the TCM, I'd guess it has an internal leak causing the 2714 if that repeated with a different valve body.

The solenoids are only messengers. The TCM tells them what to do and then is looking to see if that command was carried out.

That's where the turbin input speed sensor and the output shaft speed sensor tell the TCM what's going on. i.e. the TCM / ECM know all of the gear ratios, TPS, and when for example, 1st gear is selected, solenoids direct pressure to clutch drums and brake bands. When the throttle is applied the TCM looks at those speed sensors and makes a call about moving forward with an acceptable amount of slip at the ratio it knows to be 1st gear. If the command is followed and works, all is well.

If the command isn't followed, the TCM throws an error pointing fingers at the last people it talked to. The solenoids responsible for forward motion in 1st gear.

The same is true of P2714, it's looking for feedback about system line pressure. If it doesn't have control, it throws an error. This could be because of an internal leak. These do have a pressure port for checking line pressure with an external gauge. In trans shop, that is a last resort after their lead guy rebuilds it and it doesn't perform properly and they are scratching their heads trying to figure out what's wrong.

Make sense?

You really need to test solenoids as they come out. If they don't leak, they switch, and they flow the correct volume, they are not the cause (just a messenger) and the root cause is something else.