I found a unicorn. (M50d-r1 HD)

[Syritis]

Lets starts off by saying thank you to everyone who's helped put up the tech sections. it's been invaluable to my in my b4000 build. however I may have found something that doesn't exist. A mismatched M50D HD It maybe an R1 or it may be an HD, there's evidence that leads either way. I found it at the salvage year and started pulling bits off but haven't got the trans itself off. if youre not familiar with these trans Nathan has an awesome swap write up here http://www.therangerstation.com/forums/showthread.php?t=92909

so It maybe an R1 because
-it's in a '98 b4000
-the engine is not sohc
-the extension housing has the bungs for a mechanical t-case (though it had an electric bw1354 w/ front CV shaft)

it might be an HD because:
-it has the HD shifter stub shaft
-it doesn't have the neutral sense switch
-it has the F87A-FA serial sticker (though i can't find any data on this. all the other trans i'm sure were R1 have a F27A-ZA serial sticker)

My next thought was that it was swapped in previously but i can't see any evidence of this. no unusual scrapes, no after market silicon nor out of place zip ties or broken clips.

I'll post some pics if anyone needs clarification but otherwise i'm at a loss. i have no idea what this trans is.

 

[RonD]

If it has an extra hole in the bell housing for mounting to the 4.0l SOHC engine then it is an HD, if not then it isn't.
That is pretty much the only difference between R1 and R1HD, extra hole for the 4.0l SOHC, there is no relationship for HD and heavy duty in this model number
You can see the extra hole in the pics from the link you posted

Neutral sensor on shift plate was on the Explorers only I believe

F87A = 1998 truck, so stock original transmission most likely

F27A = 1992 truck

F = 199
2 = 2
7A = truck

It is common for Ford to keep same year of a generation of parts, so F27A may have been used thru 1997, then they changed it to F87A

 

[Syritis]

the body trim got a minor upgrade in 98 however the m50d trans started in 91 and went up until 2000 on the 4.0l. so neither of those dates really line up to anything, admittedly i have no idea about the part codes, it was just something i noticed while climbing under several vehicles. The hd trans has a slightly more durable 1 and 2 gear and syncros. which i figured my be important with the heavy drive line i'm running. so id like to get it especially as it is the trans that SHOULD be in my truck. more peace of mind for compatibility and trouble shooting.

 

[Syritis]

i figured the extra hole in the bell housing would be the final indication but then you have to pull the transmission out anyway. that a lot of work just to ID the thing.

According to nathan the extention housing isn't supposed to have the linkage bosses but the one i found definitely does.
it also doesn't have the nss, only the same red connector in the picture.
it does, without a doubt, have the HD shifter stub shown here.
so i'm still not sure.

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The tail housing extensions bolt patterns are also the same, so you will have no problem bolting up your BW 1354. NOTE* there are no bosses for manual transfer case linkages on the HD tranny, if you have an electronic case like me, than it is not an issue.

You will notice that there is no NSS (neutral sense switch) connection on the HD transmission, as there was on the R1 tranny. You DO NOT need to connect it to anything. You can leave the plug unconnected, it works perfectly fine without it.

This is the NSS connector on the R1 tranny

...
Step 6: Once the tranny, t-case, and everything else is bolted back into position, turn your attention to the shift stub. The shift stub is DIFFERENT on the HD tranny. For one the notch for the shifter has been rotated 90 degrees, and the trans end is different. So, you HAVE to use the shift stub from the HD tranny.

-Nathan-
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[RonD]

Just reach down on the passenger side and you will feel the extra hole or you won't

Also look at the Drivers door sticker, TRANS code
R1 = M
R1HD = J

 

[griz700rocket]

I asked a similar question in my build thread for my 2000 Explorer sport.

http://www.therangerstation.com/forums/showthread.php?t=162942

Ended up mine was a non-hd.

 

[Syritis]

ahh yes. I snapped a pic of the door tag just in case. guess it was a good idea since a quick look and.... up, trans code M.
darn.
still kinda weird is has the "HD" shifter in it though.

 

[RonD]

R1HD is no better than R1, R1HD would be newer if buying a used manual trans but that's about it.
I believe some R1HDs had different gear ratios, but not on the 4.0l, ohv or sohc
M5OD-R1 3.400 2.050 1.310 1.000 0.79
M5OD-R1HD 3.400 2.050 1.310 1.000 0.79

 

[griz700rocket]

ahh yes. I snapped a pic of the door tag just in case. guess it was a good idea since a quick look and.... up, trans code M.
darn.
still kinda weird is has the "HD" shifter in it though.

Pretty sure they started the short throw shifter around 95. My 96 ranger, 99 explorer and 2000 explorer all had them.