Hello everyone. I have a 1999 4x4 X-cab that I am putting a supercharged SOHC 4L from a 2004 Ranger. The motor is supposed to be putting out around 300 HP. Originally I was going to use the tranny that's currently in my truck, but I was told that my 1999 5r55e won't work with the 2004 ECU. Apparently Ford added a couple of sensors (an ISS[?] and OSS[?]) to the 5r55e tranny in 2001. I called my local transmission shop and was told that the 5r55e (in its factory stock form) had problems handling the HP/torque from a stock 4L let alone a supercharged one and that he wouldn't recommend running a stock 5r55e behind my SC'd 4L. So, my question is what tranny would you run? I'm thinking of getting a 5r55e from Monster transmission. I talked with a sales rep and they said that their tranny (and the included torque converter) would work as long as I don't increase the HP beyond ~350.

 

What's wrong with Monster's "<350 hp" unit?
So many modded oldies feature TH transmissions....must be something good about 'em but oldies don't have electronics.

 

I don't think that there is anything wrong with Monster Transmission's "Quick Ship" 5r55e transmission itself- its compatible with my application and according to them should be able to handle the power that my new engine is putting out. The problem isn't with the product, its with the price. After all is said and done, it'll cost me about $2400. I don't mind paying that, especially since they back their product with a 3 years warranty. I was just wondering if I could get an equally as capable transmission at a lower price point.

 

Trans shop was a bit off on their assessment, the "55" in the 5R55E means its rated for 550ft/lb of torque, so would be fine with 300HP gas engine

I would just go to car-part.com and look for a 2001-2011 4.0l 4x4 5R55E transmission
You will need the trans wiring harness that has the 4 extra wires for the OSS and ISS sensors

Sell your current 5R55E, if working its worth money, works with 1995-2000 4.0l 4x4

2004 computer will also need matching cluster, 1st year of digital dash, they have to be "married" to work together, Fords "better idea" to prevent odometer tampering

You may want to swap that out for a 2001-2003 4.0l SOHC computer, uses same analog cluster as 1995-2003, so same as you have now, 1999
You still have PATS to deal with in either case, but the digital dash swap is just more work that can be avoided and has no benefit to end result