2.8L -> 2.5L automatic transmission swap

[Dickinson County Comanche]

Hello all, I just picked up a 2.5 truck with no transmission to swap in the transmission and transfer case from my 2.8 in and I was curious if everything worked. I know shafts, crossmembers, starter, and torque converter swap over just fine, but I’m curious if the little things will, such as TV cable, shift selector, and CPS hole will as well. Any help is appreciated.

Edited April 20, 2022 by Dickinson County Comanche
CPS, not TPS

[eaglescout526]

You’re gonna need the tone ring flex plate for the 2.5L. That’s the biggest one you will need for the swap. Otherwise it all should work. Otherwise I am not sure of what else from the 2.5L and 2.8L is compatible. But I want to say a good chunk of 2.8L auto stuff probably won’t swap over. 

[Dickinson County Comanche]

17 minutes ago, eaglescout526 said:

You’re gonna need the tone ring flex plate for the 2.5L. That’s the biggest one you will need for the swap. Otherwise it all should work. Otherwise I am not sure of what else from the 2.5L and 2.8L is compatible. But I want to say a good chunk of 2.8L auto stuff probably won’t swap over. 

I do have the flex plate already. Got lucky there 

[eaglescout526]

For the most part you might be good to go. I’ll have to look at the set up for the TB to trans cable but it sounds like you have almost everything. Is your flex plate set up for the Renix TBI?

[Dickinson County Comanche]

6 minutes ago, eaglescout526 said:

For the most part you might be good to go. I’ll have to look at the set up for the TB to trans cable but it sounds like you have almost everything. Is your flex plate set up for the Renix TBI?

Yes, it has the little lattice for the CPS. It does have the kickdown and shift linkage installed already, but I wasn’t sure if the actual trans side would work or not. 

[eaglescout526]

You should be fine to install the trans. The Chrysler A900 series shouldn’t need a TCU I think but the 2.8L and 2.5L shared the same auto trannys from 84-86. Now if you have one of those rare AW4’s behind the 2.5L, then  I’ll be damned haha. 

[Dickinson County Comanche]

16 minutes ago, eaglescout526 said:

You should be fine to install the trans. The Chrysler A900 series shouldn’t need a TCU I think but the 2.8L and 2.5L shared the same auto trannys from 84-86. Now if you have one of those rare AW4’s behind the 2.5L, then  I’ll be damned haha. 

It’s from a truck built in 85 so it would have come with the A904 originally. Luckily the 2.8 shares the same basic driveline configuration as the 2.5 in terms of lengths and such.

[eaglescout526]

Yup for the most part you should be good to go!

[cruiser54]

Sure about torque converter compatability?

[Dickinson County Comanche]

16 minutes ago, cruiser54 said:

Sure about torque converter compatability?

I looked up part numbers on Rockauto and they were compatible. I’ve had pretty good luck with Rockauto so I trust it.

[Dickinson County Comanche]

Went out and checked the transmission behind the 2.8 yesterday and I found this! So glad it has the CPS port, I was getting worried. Although I wonder if Chrysler could have made the hole cut look any worse lol.