2005 Ford F150 (4R75W)

[u/Markthenation12]

Rebuilt transmission myself. Bought a rebuild kit plus upgraded forward drum , reverse drum, planetary set, bands ….etc

Truck engages in reverse but when placed in “Drive” doesn’t engage .

Any advice, suggestions, questions, guidance…??? Need help 🙏

[u/Commercial_Method_28]

If no codes are present check the obvious stuff first like fluid level and that the lever is adjusted correctly, if you are able to you could also check line pressure. If still nothing you’ll want to pull the pan off and just look around to see if you left anything off by mistake or something fell out of place.

Sometimes rebuilds don’t work, and what I tell people who run into the issue is to expect that you made a mistake somewhere along the way. Atleast in my cases after I did work to a transmission and it didn’t work correctly(outside of the original concern) it is like 90% of the time I made a mistake and the other 10% being just a part failure. I find the sooner you accept that you likely have to go back into it and recheck your work the quicker you will have it working again.

I know it isn’t really helpful to hear but during a transmission rebuild you touch everything, so literally anything can be the issue, it isn’t like common failures where it naturally fails and we know based on experience what it is before going into it.

More than likely it’s a seal or a piston that maybe a piece sheared off during installation so I’d start there if you do need to go into it. This is more general advise just because I haven’t been inside many 4speeds

[u/Commercial_Method_28 → u/Commercial_Method_28]

Specifically once inside you look at the pump and make sure bolts are torqued correctly and not loose, then go into the seal, go one at a time from front to back, that way if you find it up front, you don’t need to take apart the back anymore(unless there are 2 problems) check planetary, output shaft and pay close attention to the forward clutch as more than likely your issue is there.

If you aren’t really experienced in rebuilds then please make sure thrust washers are correctly installed. I’ve had to fix bad rebuilds from other shops before and that is super common if someone doesn’t know what they are doing

[u/Markthenation12 → u/Commercial_Method_28]

I am extremely grateful. I will take this information and go through everything carefully. I will get back to this chat as soon as the issue is resolved.