5th Gear Problem
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Junior Member
Joined: Feb 2024
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5th Gear Problem
I have a 1993 f-150 with the 4.9 300 in-line 6-cylinder engine and the M5OD 5-speed transmission. I bought it from a guy on FB marketplace who had said he had rebuilt the transmission, but after that, the fifth gear never worked again. When I drove it after trying some simple YouTube fixes, it still wasn't working. When I drive it and try to put it in fifth gear, it pops right out of gear as soon as I start to let out the clutch even if I hold it there. How do I fix this?
Senior Member
Joined: Apr 2023
Posts: 4,294
Likes: 1,389
From: Near Salt Lake City
Buy a new 5th gear synchro and check the shaft clearances in the transmission when you overhaul it again
There are a few videos online about this problem
Might be easier (and cheaper) to get a reman 5 speed or a good junkyard one
You will need a big puller to get the bearing off the gear on the back under the big nut
Then 5th and the synchro can come out
Replace the 5th gear shift fork too if worn
There are a few videos online about this problem
Might be easier (and cheaper) to get a reman 5 speed or a good junkyard one
You will need a big puller to get the bearing off the gear on the back under the big nut
Then 5th and the synchro can come out
Replace the 5th gear shift fork too if worn
Junior Member
Joined: Dec 2014
Posts: 21
Likes: 3
From: Bozeman, MT
Glad you got the M50D figured out, where did you get a new one within a week?!
When I bought my 94 with similar spec from a friend a few years ago these two issues were present as well; however the Zumbrota reman M50D I put in immediately (the original transmission only had 4th and reverse left) seems to have been not a great one after my warranty had expired and I had checked and fixed all the other deferred maintenance things I could find. I might soon be rebuilding this one or trying to find a wide ratio ZF5 to swap in.
Anyways, back to your misfire, did the motor do that before new trans? Make sure to check the timing if you haven't as well. Plugs, wires, cap and rotor weren't enough to smooth things out and I found the timing was off (distributer hold down was about to fall out in my case). In my opinion from experience, if you can still get a Motorcraft part, it's worth it. No exaggeration - every part my friend, the previous owner had replaced with a third party unit has failed within 2 years, the Motorcraft stuff just works. These motors were originally an agricultural water pump motor intended to run reliably for the long haul and I quickly learned the less you mess with it out of spec the more you'll just trust it.
When I bought my 94 with similar spec from a friend a few years ago these two issues were present as well; however the Zumbrota reman M50D I put in immediately (the original transmission only had 4th and reverse left) seems to have been not a great one after my warranty had expired and I had checked and fixed all the other deferred maintenance things I could find. I might soon be rebuilding this one or trying to find a wide ratio ZF5 to swap in.
Anyways, back to your misfire, did the motor do that before new trans? Make sure to check the timing if you haven't as well. Plugs, wires, cap and rotor weren't enough to smooth things out and I found the timing was off (distributer hold down was about to fall out in my case). In my opinion from experience, if you can still get a Motorcraft part, it's worth it. No exaggeration - every part my friend, the previous owner had replaced with a third party unit has failed within 2 years, the Motorcraft stuff just works. These motors were originally an agricultural water pump motor intended to run reliably for the long haul and I quickly learned the less you mess with it out of spec the more you'll just trust it.