I have a 1990 F150 4X4 with an AOD transmission, door code K. I have a 1988 F150 4X4 for parts with an AOD?, door code K. I assume this is the original transmission in this truck. I need a transmission. according to the selector letters, my 1990 has the PRNDD1 and the 1988 has PRND21. will this mean that the 1988 has a 3 speed with no OD?

Any help is good help.
.
Dan

 

K is the code for a C6, not an AOD. This would explain the selector patterns in the 88, but not the 90.

Have you crawler under the truck and looked at the transmissions? Do they look the same? Length? Pan shape and size? Number of bolts in each pan?

 

My bad......

The 1990 Trans code T.
Thanks for the input about the Code K. Will this be difficult to swap?
I can do with a C6 3 speed

 

should be pretty close you may need the crossmember and rear driveshaft from the donor truck, as the tailshafts may be different.

 

I'm no expert on parts compatibility, but here's a partial list of what you might run into:

Tranny crossmember problems
Drive shaft lengths - front & rear
Tranny/TC bolt up problems - not sure if they're compatible.

The good news is that neither tranny is computer controlled, so you won't have to dig too deeply into the electronics side.

Also keep in mind that your gas mileage will drop noticably because the C6 has no overdrive. However, the C6 is a much more reliable transmission than the AOD.

 

Can't be any worse on mileage than it already is.
Between the slipping tranny and the whatever code 44 else is wrong.
I will get it together someday........
lol