So I was having a problem with my M5R2 were the shift rail was traveling too far and pushing out the metal plugs in the front of the transmission cover (not the rubber plugs in the back). So I pulled the cover today and found the problem which is the 3-4 shift fork is completely worn uneven. Most of the fork is wore down except for a tiny sliver of it. What would cause this type of uneven wear? I'm assuming it's due to someone leaning on the shifter while driving and it ate through that side of the fork? Just wanted some input to see what others thought. The rest of the transmission looks perfect inside.

 

My guess would be the driver (not blaming you) kept resting their hand on the shifter while cruising in 4th gear

 

https://www.ford-trucks.com/forums/1...-question.html

https://www.ford-trucks.com/forums/1...cs-inside.html

 

It's a very, very common issue with the M5OD. Either there's just too much friction, or the shift forks are not made out of a durable enough material.

 

its a combination of a few things under normal conditions, assuming you didn't replace them in the recent future, with the possibility of even a few more causes if you throw operator negligence into the mix.

its much harder on the forks to go into first or reverse from a stop, as it has to slow the gear to a stop before it can engage. This increase in force doesn't translate to much at the end of the long shifter, but at the fork....its largely substantial. Over 200k miles (give or take 50k) this becomes increasingly evident on the fork wear when you are forced to crack the trans and see for yourself because something isn't working right.

1st gear is what is shifted into the most....whether it be to move up your driveway, or takeoff onto a 5 hour highway cruise...1st gets used the most. Combine that with what was said above, and it should be obvious why it wears the fastest.

Then comes neglect...resting arms on shifters is dumb, however, it's highly unlikely that to be the cause of excessive wear on the 1-2 fork, because who the hell is cruising 10 mph in 1st for long enough to decide it's time to rest their arm on the shifter. if 3-4 fork is excessively worn, and broken synchros aren't the cause, then you can be damn sure its from someone lying on the shifter.

See my shadow changin', stretchin' up and over me.......

 

I had the exact same issue (search my ID and "M5OD" for pics & discussion if you'd like). In the end, I can't say for sure what the root cause was. I just swapped in a new fork and called it done.

 

This thread popped up and I want to correct my statement ^^^ from a couple years ago. The wear I had was on the 1-2 fork. The worn fork in this thread is the 3-4.

You can read about my experiences in the thread below, now updated with new pics taken yesterday showing that the new 1-2 fork is as good as new, seven years and 10K miles later. I try not to abuse my stuff. That matters.

https://www.ford-trucks.com/forums/1...-inside-2.html