In 2013 I got a 90s M5R2 transmission and put it in my 77 2wd 302 F100. Yesterday I was driving it and lost 2nd gear. I've read several posts and done some research and from what I'm reading it seems to point to bad shift forks. Just wanted to ask and see if I'm heading in the right direction to replace my shift forks.

So here are the symptoms. I have 3rd, 4th, 5th, and reverse gears-- these gears operate normally. Sometimes when I move it thru several gears I can get it to operate normally in 1st. But I've not got it to operate in 2nd no matter what I do. I can get it to shift into 1st and 2nd but 2nd never operates and only sometimes does 1st operate. I don't have any grinding noises it just doesn't do any think when I put it in 2nd.

I just want to rule other other possibilities before I order parts. Last year when I swapped the transmission I put in

NEW:
clutch master
clutch slave
throw out bearing

RE-USED:
fly wheel
clutch
pressure plate
pilot bearing

I have what I think is a bad synchro ever since I installed it. When I pull up to a light and shift from say 3rd to 1st I get a little bit of a grind. When I shift from 2nd to 1st no problem. I don't think this is the problem that I'm currently having but just wanted to throw that out as another symptom.

If it is the shift forks does it make sense to replace both the 1-2 and the 3-4 shift forks at the same time? Or just the 1-2 shift fork?

I found Motive Gear shift forks on Amazon: 1-2 for ~$32 and 3-4 for ~$30.

Thanks for any help.

 

If the truck can be down, you can pull the cover and check the fork wear before you order. The shift forks on the MR1 and MR2 are different so order accordingly. The gasket is rubber and probably doesn't need replacing. One plus is it is easy to change tranny fluid when the cover is removed. I have a recent thread about moving the shift rails to get the forks off. You should probably look at it as I think it works great. Also the plugs on each end of the rails probably need to be replaced and they are different. You will have three rubber plugs that will leak when driving when they get brittle and should be replaced with the metal freeze plugs. Plenty of info in here about what you need. Good Luck Sandy

 

This isn't my main vehicle. So I've got some options.

Yes. I have picked parts for the M5R2.

I guess you mean add fluid from the top?

I saw your post. I'll look at it in detail some more.

These plugs that you mention are these the 3 rubber plugs? Or are they some kind of plugs on the rails?

Ok. As far as the 3 rubber plugs I've checked them and I'm good.

Thanks for your help.

 

I'm not sure if the floor pan in the older trucks is removable like the OBS trucks, but if it is I recommend pulling the top off of the trans. Its fairly quick and will let you know right away if it is a fork issue. It will look something like this.

​​​​​​​
I don't have a picture of the fork assembly, but, if you have a bad one you will see the tabs that are worn off. They will be noticeable.

 

I got my shift forks today and got them mostly installed. I got the shift rails pulled out and the new forks added back on the rails.

There were some ball bearings that popped out and I got those added back in correctly. Also, the detent pin fell out and I put it back in the middle rail. I think I did that right.

This post and item #7 shows them and was real helpful.
https://www.ford-trucks.com/forums/1...ail-issue.html

What I'm having problems with is getting it reinstalled. I've got the top cover reinstalled a couple of times but it's not shifting. I was able to get it into a couple of different gears and pull move forward... But it's not shifting easy.

I think some of it has to do with putting the shifter back in the top cover. The last time I got it in a couple of gears and then took the shifter off and it sounded like a spring flung back. I put the shifter back in and couldn't move it at all. I have moved some of the gears a little bit in the transmission so the shift rails would fit down over them.

Any thoughts?

 

May have to pull cover again and make sure its in neutral then reinstall the cover. The first time I did it, it took me twice to get it right.

 

Did you have the transmission in neutral when you took it out? If so, as Mudsport says, the shift lever must be in neutral when you replace it. I probably had mine out 5-6 times and it went in like butter every time. If you moved the gears to line up with the forks you probably had a fork move over the gear when you heard the noise. The cover should just fall in the tranny slots when the trans and shifter are both in neutral. If it doesn't just go right on, slide it back out and take some pics of both.

 

So I've been able to get the top cover back on it and the bolts in.

I did take pics when I took it out. I've tried to line up the shift forks in the same place and the gears in the same place.

When I took it out I think it was in 2nd so I could take the bolt out of the shift lever.

I'm getting the cover on ok. It does take a little bit of fiddling. I'm aligning the shift forks over the transmission gear collars (not sure what to call them). But once the cover is on it's just hard to move the shift lever.

I've started it up and moved it in whatever gear it's in and tried to rock it a little to see if I can get it to move to another gear. But so far not much luck. I'll keep working on it tomorrow and see what happens.

 

Are you moving the rails to line up/move the shift forks? (not that you should, just asking) Also if you think you were in 2nd when removed, put the lever in 2nd before putting it in and then try to set it in.

 

Yeah I've aligned the rails. With the cover off I've tried to change gears but it's pretty hard.

here are a couple of pics.


​​​​​​​

 

For neutral they are not aligned. The rails should be at the edge of the opening on the left for neutral. Shift it into neutral and see how it looks. Also the hole looks like light is coming through. Did you replace the metal plugs that go there? Did you ever move that top rail?

NEUTRAL

 

The transmission is in FIRST gear in that picture. You need to snap the slider on 1-2 gear to the middle position(so it looks like the slider on 3-4). You should see the brass synchro on each side of the slider

Slip a screwdriver on the left side of the slider and just give it a gentle twist and the slider should snap back to the middle. Then align the forks on the lid so they are in neutral position.

 

Not to hijack his thread but while we are waiting, where are the sliders when in OD?

 

OD is in the tailhousing. 1-4 sliders will be in neutral and OD can then be engaged.

 

Got it Thank you