4R55E to 5R55E transmission swap.

[chpalmer]

We have used Aerostars in our company for 20 years. All 4WD. We must like them.. And we do allot of logging roads with them.

Our first 96 and last van we purchased was acquired two years ago with just 60k miles on it. Ive been bouncing around the idea of changing out the transmission with a 97 5r55E model and suddenly due to a torque converter failure went full bore with it. So to help with others that may want to consider this..

The 4r55e (96) and the 5r55e (97) are almost physically the same and will bolt right up. Difference is the starter changed in 97 so you will need to replace your 96 model starter with a 97 unit.

The 5r55e has an OSS (output shaft sensor) that the 4r55e does not have. Using the 96 harness and computer will shift the new trans just like the old one. I.E. only 4 forward gears. You need the OSS sensor wiring run to the PCM, and a 97 PCM to make the thing use all 5 gears. Im actually considering an aftermarket controller.

We have a 97 with a ton of miles on it that is going away soon and am going to take my harness and PCM from it. I have used the 97 PCM in this van to try and get 5 gears in the past with some success.. But without the sensor it winds out before shifting to 2nd.

Im still looking for a harness diagram for a 97 Aerostar to document this better and will post it here when I do.

Meanwhile.. any suggestions for headers that will fairly easily adapt to these vans?

 

[BrooklynBay]

Welcome to this forum! Do you have a 3.0L or a 4.0L engine? The 3.0L uses a 4R44E or a 5R44E transmission. They are very similar to the xR55E version except that it has a different number of clutch plates. The xR55E version has more clutch plates to provide more torque & holding power.

 

[chpalmer]

4.0..

4x4 models only came with the larger engine and as an extended van. Our first van was actually an 88 short bed windowless van with the exception of the back lift gate. All the rest (9 of them) have been the 4wd models.

Generally we have picked these up with 120k+ miles on them and would take them straight to the trans shop for an upgrade/rebuild. But most were 95 models with the earlier A4LD transmissions.

Last three were 2x 97's and then this 96, the subject of this swap..

Strike=Another thing Im noticing as of yesterday is that the 97 we still have either came with or had a vacuum storage canister installed just over the AC evaporator under the hood which the 96 models did not. Ford had a bulletin to add one to these vans according to a Ford master mechanic friend of mine.- EDIT= Strike that whole paragraph. Im just obviously unobservant and missed the fact that they all have them. Maybe we all had the Ford fix or my buddy remembers wrong. But while diagnosing I found my one way valve was leaking back and replaced it.

More information than you probably wanted to know but the coffee is starting to work.

 

[chpalmer]

Grabbed the parts from my retired 97 yesterday. I did take some pictures and Im going to post them here in a day or three.

But- success. Ive got 5 working gears in my 96. I only had to run one wire to the PCM. Ill explain the process in the coming days. Luckily my donor PCM has the same fuel tuning as the original. That is very important. Im going to drive the 97 (which now has the 96 PCM) to the metal yard tomorrow and then keep the PCM to swap back if needed.

The 97 with the 96 PCM is missing the signal from the differential mounted sensor and does not shift right now. But it should make it to them a mile away just fine. If nothing else hopefully this will be documented for anyone else looking. Ive had quite a time trying to gather info and there is not much.