Won't shift, M50d
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Junior Member
Joined: Oct 2014
Posts: 10
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From: Aspen, Colorado
Won't shift, M50d
Mazda M5od manual transmission on a 1992 F150, 5.0 engine, 4wd. When we bought the truck it needed shift forks (drove fine in third and fourth gear). Replaced the 1-2 shift fork, drained and refilled the transmission. Drove fine for a little bit.
Now, if I start in gear it shifts fine through the gears until I let go of the clutch, then press clutch and it will not go into any gear. I can see through the view port that the slave cylinder is moving when the clutch is pressed (no idea if it is effective though). I've bled the clutch master cylinder. It will drive sometimes, but if I push the clutch to the floor at any point I have to turn the truck off, put it into gear, then it will at least drive in that gear and may shift ok for a little bit. As soon as I take the pedal to the floor though, nothing. No leaking fluid from anywhere, including the slave cylinder.
Master cylinder appears to be aftermarket and has no internal, removable rubber bladder (or it was lost by previous owner). There were some metal shavings in the oil when it was drained and refilled, but no chunks.
Slave failing? Master still needs bled better? Missing rubber thingy? Thoughts before I buy an entire clutch kit, pull the tranny? How to check the function of the slave cylinder? What is the ground speed of a sparrow?
Now, if I start in gear it shifts fine through the gears until I let go of the clutch, then press clutch and it will not go into any gear. I can see through the view port that the slave cylinder is moving when the clutch is pressed (no idea if it is effective though). I've bled the clutch master cylinder. It will drive sometimes, but if I push the clutch to the floor at any point I have to turn the truck off, put it into gear, then it will at least drive in that gear and may shift ok for a little bit. As soon as I take the pedal to the floor though, nothing. No leaking fluid from anywhere, including the slave cylinder.
Master cylinder appears to be aftermarket and has no internal, removable rubber bladder (or it was lost by previous owner). There were some metal shavings in the oil when it was drained and refilled, but no chunks.
Slave failing? Master still needs bled better? Missing rubber thingy? Thoughts before I buy an entire clutch kit, pull the tranny? How to check the function of the slave cylinder? What is the ground speed of a sparrow?
Member
Joined: Jan 2018
Posts: 11,256
Likes: 1,770
From: Memphis, TN, Earth, Milky Way
Unladen, or clutching a creeper on a coconut?
Click these & read their captions:
(phone app link)
(phone app link)
The rubber diaphragm prevents the fluid from absorbing humidity as quickly, which isn't nearly as important in the clutch system as in the brakes. But since the clutch cap is VENTED, it also keeps trash out of the fluid & MC, so that may be why yours is going south.
Click these & read their captions:
(phone app link)
(phone app link)
The rubber diaphragm prevents the fluid from absorbing humidity as quickly, which isn't nearly as important in the clutch system as in the brakes. But since the clutch cap is VENTED, it also keeps trash out of the fluid & MC, so that may be why yours is going south.
Junior Member
Joined: Aug 2019
Posts: 8
Likes: 0
From: Upcountry, South Carolina
My M5OD, in my very high mileage '93 F-150 can be reluctant to shift into first or second sometimes. I haven't had the truck long enough to change the tranny fluid, so that could be an issue. What I do is put the tranny into neutral, let out the clutch, then depress the clutch again and it shifts into the gear I've selected.
I think that new fluid will help, but it might not. I'll see.
I think that new fluid will help, but it might not. I'll see.