Can I replace 6HP21 with 6HP26 in a Ford Territory 2016 TS MkII petrol RWD

[cornelis]

Hi

The reason for the question is that my Territory has a slight whining noise whilst under mild acceleration between 94 and 106 km/h on smooth asphalt. Place it in 5th gear and it is gone at the same road speed.

I have driven 3 other identical Territory's with the identical 6HP21 transmission and mine might in fact be the least affected of these 4 cars. I didn't have the opportunity to test drive at that speed on a smooth asphalt road when I bought the car. Not that it mattered as they all seem to have it. Also, the noise is very local and as a driver or passenger at the front I can hear it, but as a back passenger I can't hear it. Before the statutory warranty expired, I obtained 2 expert opinions, and both said that the potential for a claim was nil as the transmission operates smoothly and correctly. I accepted that advice.

I have heard that the Control module in the 6HP21 and 6HP26 are the same. The tail shaft would seem to be the same for all petrol versions from 2011 till 2016. I have checked the length of the two transmissions, and they would seem to be the same within a few mm, if not identical.

So here is the question: If I take the 6HP21 out of my car and place the transmission control unit of the 21 into a spare 6HP26 would that 6HP26 work in the Mark II Territory?

I put in an air cooler to avoid the risk of milk shaking and when I did that the transmission fluid was very dark but did not smell burnt. After that the transmission was serviced and 5 or so litres of new fluid was put in (genuine stuff) and it was still blackish. The viscosity seems fine. I am contemplating to flush the unit with genuine fluid till it returns to a honey colour.   

I am also contemplating to remove the tunnel and carpet and put in loaded vinyl as the frequency is probably in the order of 800-1500 Hz and if I get it down by 10 dB it would not be noticeable anymore.

Look forward to some comments constructive or otherwise.

Cheers

Cornelis

[Roland@pcmtec]

Not possible as the 21 and 26 clutches and lockup are different, it would either fault, drive terribly or grenade the box. 

[Puffwagon]

This same questions was asked elsewhere and @Whiteford replied that it was possible and a significant upgrade.

[Romulus]

Need to work out how to retrofit the 8HP75 to the Falcons. I've one fitted in my BM, it craps over any built 6R80 or 6HP26. The spread of ratio's is awesome, has inbuilt launch control and can comfortable handle 1000hp in AWD mode.