2015 PIU 3.5 transmission

[rev_marcus]

I have a 2015 PIU with the 3.5 liter EcoBoost. There is a terrible noise coming from the transmission area when the car is decelerating at lower speeds. My mechanic states that the chain is getting loose in the transmission and that the transmission for this particular vehicle is very specific which kind of makes sense to me I guess (different gearing?). It definitely sounds like a chain rattle, at least once he said it, i'm wondering if anyone else has experienced this.

 

[peterk9]

I don't believe I've ever heard the word "chain" referenced in any posts about transmission issues.

Peter

 

[rev_marcus]

Yeah I don't know. Planning on taking it to a few other places. But that is what they said. Can non PIU transmissions work, engine specs being the same etc? Reading through the Ford lit the suffix DRM seams to be specific to the 3.5 eco in the PIU while there are multiple da5z-7000's. Anyone swap in a civilian transmission to a similar year PIU, I guess is my question. I don't have the facilities/faculties to rebuild a transmission, but feel confident I can swap on this vehicle.

 

[BrettS.]

First you need to figure out is the noise coming from the PTU or the transmission. Chain rattle sounds more like a PTU issue. PTUs usually fail due to lubrication issue. The gear oil gets hot, cokes up, and is never changed. Bearings overheat and fail. Also take out the case where the bearing cone is mounted. Could also be the engine timing chain if it is more pronounced at cold start. That is the only place that actually has a chain. If you are going to do a trans swap you have the 6F55 transmission. The non-Ecoboost ones usually came with the 6F50 transmission. If you go used look at the service parts identification decal on the drivers side door. J is the 6F50 and C is the 6F55.

 

[rev_marcus]

Thank you for the replies. I took it to two more places ended in it up being the PTU. Got the new one in and finished installation yesterday. Everything seems to be up and running good now. Thanks!

 

[peterk9]

Appreciate the update.

Peter