How to: - M5R1 Rebuild thread | Ford Explorer Forums - Serious Explorations

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How to: M5R1 Rebuild thread

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Explorer Addict
February 5, 2003
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Year, Model & Trim Level
'95 XL 4x4
AKA M5OD and I've also seen it called Toyo Kogyo.

My tranny had been hard to shift for the last 60k. The entire hydraulic system had been replaced twice and the clutch itself had been replaced one. I finally pulled the damn thing and took it apart.

This is what I found:




The syncro rings were probably fine but I replaced them anyway.

I think these are some of the new:

And these some of the old:

This thread assumes your tranny is currently like this:

I had not intended to write a how to but there just isn't a good one online.

If you need help getting it apart there are threads here and here.

Start by putting the main shaft in a vice. You'll notice I'm using an old sock to protect it. There is already one new bearing on it too. It is right above the lip that is just above the sock. Its a good idea to rub some ATF on all the bearings before you install them:


Second gear goes on next:

Followed by the syncro ring:

The syncro hub/ring goes on next.

The sleeve is directional. The reference dot faces up in this orientation or towards the back of the tranny normally oriented. This hub is not directional if you happened to disassemble the hub/sleeve.



Find this bearing and collar next. The bearing is identical to the first one you put on:

The bearing goes on the collar and into first gear:



Next put the ring on the gear:

And slide it on the main/output shaft:

This bearing needs to be pressed on next. I took it to a machine shop as I don't have a press:


Get the bearing pressed onto the input shaft at the same time as well.

Your main/output shaft should look like this now. This is everything that gets assembled on this side with the shaft out of the case:

Flip the shaft over in the vise now:


This bearing goes on next, you are prelubing all the bearings with ATF right?


Now put third gear on:


The ring can go on next or you can put it on the hub/slider assembly. Note your original third gear ring will probably look like the one on the left:


My replacement kit didn't have one like that. I called the place I bought it and was assured it would be fine.


Put the hub/slider on next. Note both the hub and the slider are directional. This side faces down or towards the rear of the tranny:

This side faces up or towards the front of the tranny. Notice the chamfer on the slider too. That side has to be up:

Now find these pieces:

The inner piece goes on first, the shaft is keyed to it:

Next put this bearing:

This snap ring goes on next:



Mine was tight but if yours feels loose you need to measure the end play and get a thicker snap ring. Consult the FSM for that.

Find this needle bearing and put it in the input shaft. Notice the other bearing you should have pressed on already:


Put the counter shaft and input shaft in the case like this. Note there are two inner bearing races pressed onto the counter shaft. Mine were fine so I did not swap them:


Put the fourth "gear" ring on the main shaft:


And put it in the case like so:


Find your main bearing races. I think the larger one is the output shaft race but don't quote me:

Install the output shaft race and then the counter shaft bearing. You should be able to wiggle each shaft and the race/bearing should just slide in. Do not put them in all the way, let the bearing retainer push them in the last bit. You'll be taking this apart again if they are in too far when you can't get meaningful measurements on the front side:


Both installed:


Rear bearing retainer:




Now come around to the front side:


Funny, it feels like we just did this:



Now take this measurment (A):

And this one (C):


Perhaps this one too (D):


Why not one more (B):


Per the FSM:


Find the right amount of shims for the input bearing race:

You can see the tolerances from the FSM in this pic and notice how it says install shim this side out? It means the chamfer on the thickest shim goes out in the sense of the front bearing retainer, NOT in the sense of the transmission. Don't ask how I found out:

Its kinda hard to see but there is the chamfer:

Find the countershaft shim. I got lucky and didn't need to replace it although it was at 0.24mm of a 0.25mm tolerance:

Put the oil baffle in and some grease to hold it together while you turn it upside down. This is an example of WAY too much grease. I wiped most of it off later. Also notice the little trough at the bottom left of this pic. Keep that clean, that is where ATF flows in from the case:

Cleaned up:

The FSM said to wrap the splines so you don't damage the seal:

Don't forget this little plastic piece of **** oil slinger. I did and had to take the retainer back off when I found it in the parts box. Turn it while its down there and it will lock into place:


I apparently was too far in the pint glasses to get a pic of this but put a small line of RTV (making sure not to get any in that ATF trough) and bolt the front bearing retainer on.

With the tranny on its side find this ball and collar:


The ball goes here:


And then the collar slides on:


Put the two piece bearing in the fifth countershaft gear and slide it on the collar:



This is the main shaft fifth gear. The longer side goes toward the front of the tranny:


Perhaps it goes here?


Now find this. The rebuild kit comes with a new o-ring for it:


It goes here:


Stick the fifth/reverse shift lever on it. The wider end goes up top:



Another pic I apparently missed but this washer and snap ring hold the two together:


Put some RTV on the bolt and bolt it in. I don't think this one actually needs RTV but the FSM said to so.......


Now put all this together:


And slide it in:


You may have to push it down to get the bolt hole to line up:


This is the bolt and you need RTV on this one:


Now find these pieces:


Two here:


And the retainer over them. The syncro ring and bearings for the reverse gear seem to have joined the party:


This collar goes on the main shaft:


Put this reverse gear on the counter shaft:


The longer flange on the main shaft reverse gear faces the front of the tranny:



This spacer goes on the counter shaft:



Pour some ATF in the bearing of the reverse idler:


RTV the bolt:


And bolt in the reverse idler assembly:


The counter shaft bearing just slides on:


Hand tighten the nut on it:


The output/main shaft bearing has to be pressed on:


Until the gear under it doesn't move up:


Should be hereish:


Now lock the tranny into first and third:


Torque the counter shaft nut:


And guess on the main shaft nut:


Stake them in place:


Clean the transfer case mounting side of the housing if you desire. Probably not necessary as its not sealed. Notice the drain at the bottom of the housing:


Do clean the mating surfaces well. That plastic cap goes in the hole right below it:


Pour some ATF in the bearings and RTV up the mating surface:


You'll have to tap the housing on with a mallet to get the bearings seated in it, then bolt it together:


If you haven't already, pull the rubber plugs out of the top cover and hammer in the freeze plugs that came with the rebuild kit:


Put this rubber gasket in:


Bolt the top cover on and you are done:


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Here are some tips on reassembling your hub/slider assemblies if they are apart.

See the missing splines? That is not where the keys go. Look at the top, the middle of where the three splines are missing material are where the keys go:


The keys are different sizes. If you have the wrong ones they won't fit right in the hub:


The easiest way to put everything together is put a ring on the hub/sleeve like this:


Set that side down on your workbench.

I don't have any good pics of the process but the keys go like this and the spring goes in as you can see. There is a hole the spring goes in. If you put it the wrong way the spring won't cover all the keys:


Carefully turn it over making sure the ring stays with it. Then take the ring off and put the spring on the other side.

quick question though on this fanstastic write up where do i get the gears and the rebild kits from for this please email me at thanks

really great thread, the rebuild was a walk in the park using it as reference! 100 thank you's for putting it together, especially the shimming portion. kudos!

just a tip for anyone else who uses this thread...I had a hell of a hard time finding the shim kit for the input shaft, literally called every transmission shop in my area and nobody carried anything close. Talked to a guy at an AAMCO and he basically told me when they rebuild these transmissions that they just put back what was in it before, which to me sounds like they dont even check the input play. sketchy..? To order thru Ford would have taken a week. finally after much headache i was pointed to a Transtar in my area. They were very helpful and were able to find a shim kit within minutes and order it for me, cost about $30 and delivered next day! So if anyone has trouble finding shims for this transmission try Transtar first, that would probably be your best bet.

Thanks, this might be just what I needed

Great thread. I'm currently rebuilding my Rangers transmission, M5R1 in a 94 4.0 4wd. I have an issue though that I can't seem to resolve. I've looked and dug and looked more but I cannot find in any picture or diagram what I'm looking for. On my tranny the race for the input shafts bearing does not just sit in the trans housing. It's actually in an aluminum eccentric collar that then goes into the trans housing. I should have taken a picture, and I will tomorrow. But every picture I find just shows the race going straight into the transmission housing... I find it hard to believe that someone took the time and effort to machine this housing and make a collar for the race to repair a damaged housing, but I honestly think thats whats happened. I'm really hoping someone will chime in here saying they have seen this also. It's driving me nuts because this collar is worn and causing the bearing race to not sit properly. It would probably be fine, but it makes it impossible to get a proper shim on the race, which lets the input wiggle and it has actually worn out the input shaft on the pilot bearing end to the point where I'm having to replace the input shaft.

Picture from above showing the input bearing race just sitting in the housing, unlike mine.

Is it possible to remove the input shaft without tearing apart the whole transmission? My pilot bearing was disintegrated when I replaced the clutch and slave a while ago. I had notice that the end of the input shaft had been grinded into because as well but didnt do anything about it and now its causing the pilot bearing to fail way to early. The pilot bearing lasted only 3-4 years as opposed to about 13 years for the first one.

Is it possible to remove the input shaft without tearing apart the whole transmission? My pilot bearing was disintegrated when I replaced the clutch and slave a while ago. I had notice that the end of the input shaft had been grinded into because as well but didnt do anything about it and now its causing the pilot bearing to fail way to early. The pilot bearing lasted only 3-4 years as opposed to about 13 years for the first one.

No. Everything has to come out of the case to get the input shaft out. It's a full rebuild. Although, it's pretty easy to do if you know what you are doing. Getting the trans in and out is harder than the repairs.

Edit: On second thought, I think on the R1 that the shaft will fit through the front of the case (it won't on the R2). If you get the front cover and bearing out, you might be able to take the input shaft out the front. But that might make things harder than they need to be. And it doesn't save much work over pulling everything out the normal way. If you have to get into it that far, I would take the rest apart anyway, give it new bearings and synchronizers, and fix anything else that needs fixing.

What type of equipment would I need to accomplish the rebuild? I know I could do this. From the looks of it I could use hand tools for most of it but I would assume that some steps would require a press or some other special tool.

You don't need much of anything special. A press is useful, but normally not required. Most of the parts are a loose enough fit that you can knock them on and off carefully. I think there is only one part that needs a press. The rest is a handful of sockets and a wrench big enough for the mainshaft nut (~2"). A socket for the countershaft nut is useful -- 32mm as I remember.

Southwest Gear has a good rebuild DVD that is worth getting if you want to do this. They sell parts the too.

I'm seriously thinking about doing this. What parts are the likely ones I'll need? I know I need to replace the input shaft because it was grinding 4 years ago at the pilot bearing. Do I need new gears or just bearings or also synchros as well?

First be aware that there are different versions of this transmission (different tooth counts for certain gears, different style synchronizers, etc.), so be careful that you are getting the right replacement parts. The gear tooth counts will identify which parts you need.

Unless there has been some damage to the gears or it was run out of fluid, the ones you have are probably fine. When you open it up you will be able to inspect the gears for any damage. If you don't have any issues now other than the pilot bearing end, the other internals are probably fine.

The bearings may be fine too. But they aren't that expensive, so it is almost one of those might-as-wells, like replacing the clutch while it is open. That's up to you if there are no signs of damage or heat.

I would check the synchronizer rings very closely, and definitely replace them if you can get new ones. Generally they are pretty inexpensive. Some of these transmissions have a special three-piece ring for second gear which is hard to find and quite expensive. You might not want to replace that if not needed. I would definitely try to replace the synchronizer rings if I had it apart.

Check the tips on the shift forks for wear. Replace them if needed. If there is slop in the shifter, you can get a shifter bushing kit for about $20.

Check the three rubber plugs in the back end of the top cover (they cover the shift rails). If these are still the factory rubber plugs (which are known to leak), you should replace them with metal freeze plugs. Dorman 555-108 is what you need there. Just tap them in with a socket and hammer.

Input shaft and output shaft seals are a good idea. You will need RTV to seal the front cover and tail housing. You will need some replacement nuts for the mainshaft and countershaft if you take them off.

That should be about it unless you find something wrong in there. Be careful not to lose any of the check balls.

Well the tranny has 180000 miles on it and its not that smooth with shifting especially from 1 to 2 and 2 to 1. Hasn't been smooth for a longtime. So I assume there must be something in there that would resolve that issue.

The not smooth shifting could very well be coming from the pilot bearing problem. It could also be in the clutch/slave. Or it may be wear in the synchro, etc. You can't really tell if there is damage to the trans parts until you inspect them. When you have the trans out, pop off the top cover and you will be able to see most of it.