4 speed 4r55e to 5 speed 5r55e swap. Is it just a drop in?

[Justin_]

Hey guys. Still looking at possibilities. I have a '95 4.0 OHV engine that im fixing up and going to drop in another car. I found a '98 Eddie Bauer 4.0 SOHC. The car and paint is super clean, but has engine problems. Im looking at dropping the '95 OHV into the '98 once I finish the rebuild.

Looking at the transmissions, the '95 comes with a 4 speed 4r55e, and the '98 come with a 5 speed 5r55e. They are both automatics and both are bolted to 4.0 engines. Is it possible to just bolt the 5 speed in with the '95s engine? Will I need to do anything special with the ECU, or would I need to get an ECU from a OHV with a 5 speed to get it to recognise the additional gear?

Thanks guys!

 

[JK080]

Both transmissions are built the same with the same amount of parts in them, the computer from the 98 makes it a 5 speed by turning the overdrive on to overdrive 1st gear to make 2nd gear, the 95 vehicle just shifts to 2nd. So they both are technically 4 speeds just the later model controls it differently, so to get it to shift through all "5" gears you will need to use the later model computer.

Interchangeability I am not so sure about, I believe the transmissions will swap around but I don't know what issues you might encounter by swapping computers.

In the end both transmission have a final drive ratio of .075 so there is not much to gain except a extra shift.

 

[Mbrooks420]

95 was a strange year, as it was a new generation, but the only one that was obd1. I’d guess you’ll run into minor wiring issues.

 

[JK080]

95 was a strange year, as it was a new generation, but the only one that was obd1. I’d guess you’ll run into minor wiring issues.

Oh yeah that too, good point!

 

[Justin_]

Both transmissions are built the same with the same amount of parts in them, the computer from the 98 makes it a 5 speed by turning the overdrive...

...In the end both transmission have a final drive ratio of .075 so there is not much to gain except a extra shift....

...was obd1. I’d guess you’ll run into minor wiring issues....

So in the end it wouldn't affect much on the high end and could end up with wiring issues. Got it. I'll probably just leave the '95 engine with the '95 transmission than.

Thanks for the help guys!

 

[gmanpaint]

95 is obd1.5

The trans is mostly the .5 in the system. A few items like the gem are also part of it.

96 also uses the 4r trans, but is full on obd2.

The 5r trans harness would be an issue with the 95 engine harness where they tie into each other. Pretty sure everything is 3 wire in it. You might need the 120 pin ecm to run the 5r, as the 95 has a 60 pin.

To make the 5r run off the 60 pin in theory could be done I suppose, since the 95 is setup for the obd2 trans as is. What all needs done for that too work, is well above my pay grade. Lol

I imagine it's more than just a flash tune of the ECM, as was mentioned, the wiring would need redone to both harnesses.