Story starts when I started my truck this morning and I put it in reverse to back out of my driveway, but my truck did not move at all. I didn't think much of it because I have mud tires and it snowed a lot and I thought it the tires were spinning. I put it in 4x4 High and tried giving it gas again but it seem like it was just rolling backwards and it finally engaged in 4x4 from rolling backwards about 2 feet. So that time, i didn't think anything of it...

Later on the day i parked in front of my garage again and then I had to back out again to go somewhere, this time It wasn't going anywhere, I put it in reverse and the truck does "bump" like it is going into the reverse gear but when you hit the gas it just revs up like its in netrual. Put it in 4x4 and it still would not move. The truck drives fine in Drive though, First Second and Third gear all seems to work flawless. My edge programmer pulled up two codes and said P0720 and P0722 which is basically Output Shaft Speed (OSS) Sensor problems. Went to the dealership and bought a OSS and I replaced it and unplugged the battery for 15 seconds. Started it up, still no reverse. I started to drive the truck in Drive and multiple things happened from that OSS. My speedometer stopped working, O/D turned off, my speedometer said "TRANS FAULT", and was stuck in first gear... But half mile later, it all went away so maybe it was calibrating. But as soon as i got back home it did it again... So i turned off the truck and turned it back on and went away again. So i'm stuck...

If anyone has ideas or any suggestions, that would be great. I am hoping that its nothing internal with the reverse gear broken off or something. But i hear no rattle or any noise from the transmission when driving or putting it into reverse. Thank you

 

Conclusion: Low & Reverse Band broke. Getting the transmission rebuilt with high performance transmission rebuild with the redesigned reverse gear and kevlar gears from Oregon Performance Transmission. I guess ford messed up on the design of the reverse gear in the truck, and when I threw my 35" tires on it with a 3.55, it was just too much for it. Whats odd was my transmission was some type of prototype because its a 4R70W transmission case with 4R75E internals.

 

Sorry,no such thing as low/reverse clutch in this trans.. never heard of kevlar gears either. I'm assuming you had no engine braking in manual low, which would indicate a broken rear band. All joking asside, your reman consists of a kevlar clutch module and what??????? Redesigned reverse??? huh??? More info PLEASE!!!

 

Also as an FYI, Kevlar is a bad idea for these transmisisons.

Darrin

 

Looks like my kit is not the oregon performance kit, but is the Alto Red Eagle Kit with a kevlar low / reverse band. I talked to the guy who is rebuilding the transmission about how the kit enhances the reverse and he said about with the reverse piston hole is boared out deeper to handle the heavier pressure to eliminate failing.

@Darrin: Why is kevlar a bad idea? Shouldn't it be fine if all the internals are being upgraded with a performance rebuild kit?

 

I also have the same reverse problume took it to a trans shop, and they pretty much have told me that they think its the low/reverse band, they havent actally looked at it yet, but her said his abot 90% sure thats what it is. so I would like to know what this upgrade is all about so I can see about getting it done to mine.

04' FX4

 

im with you guys. My truck started pitchin a fit and quit reversing on me two days ago and its really annoying. I havent taken it to a shop yet but i got an idea the cost is going to be around 1500-2k. however i did find a guy on craigslist that will rebuild it on the truck for 300 labor, I buy the parts. But ebay looks a little better. there a shop in pheonix called gentry transmissions that sells a rebuilt 4r75e for 875 shipped w/ 2 year warranty... any thoughts??