Hi, i have a 2004 F150 4.2L with RWD r470w. Markings in the bell housing indicate a rebuild in 2009.

The symptoms i was having were that when starting off in Drive the engine would just rev and act as though it was in nuetral. I'm sure it wasn't trying to start in 2nd since it wouldn't move at all. On rare occasions it would work in drive.. so long as it didn't need much torque. If i manually moved it to 2nd gear then i could start fine and could subsequently shift back up to Drive and the shifts from 2>3>4 would all be fine.

I've dismantled the transmission and found a few things though i'm not sure if they're the cause of my problem or not.

1. one of the 1-2 accumulator springs were broken (ordered a whole new accumulator assembly $13)
2. there was no snap ring on the top plate for the 2-3 accumulator (will use the snap ring from the new 1-2 assembly since they're the same part#)
3. the direct drive to hub bearing was completely pulverized... not a single ball left and the two backing plates were just spinning against each other. This caused a ton of metal debris throughout the tranny but the only other damage i saw were a handful of chipped planetary teeth.. they seem to still be good enough though (new bearing was only $4)
4. the clutch plates all looked ok.. but i have replacements anyway(including steels)

Anyone have any idea of what may have caused my symptoms? This is my first transmission rebuild so my diagnostic skills are lacking. I appreciate any help or tips that you can provide.

 

I learned that the 2-3 accumulator isn't intended to have a snap ring, so that's a non-issue. Though, i don't think the retention clip's edges were properly seated into the recess.

I still have no clue why first gear wouldn't have been working.

 

No one has any idea what might cause first gear to not work in a transmission?

 

what codes is the truck throwing??

 

The truck wasn't throwing any codes. It just wouldn't move if you were in Drive and tried moving from a complete stop. it moved fine if starting from 2nd though.

I bought the 1-2 accumulator springs and the direct clutch outer bearing (part# 7f240) from the ford dealer. I'll be throwing it back together this weekend unless someone lets me know of something else i should be looking at.

 

Likely debris from the destroyed parts clogging the passage that feeds the first gear engagement circuit. Be sure and flush the tranny THOROUGHLY to get out all the crud. You will also want to do the same with the cooler lines (maybe even a reverse flush to force out any crud that is too big to flow through the cooler passages during regular fluid flow). It's amazing how much crap can be left in them.

Better yet, replace the cooler and compeletely flush the lines. It's the only way to be certain that a bunch of leftover debris doesn't migrate to, and destroy, your newly rebuilt transmission.

Brad