M5OD-R1 vs. M5OD-R1HD

metalmacguyver · Sep 15, 2007

I have had trouble finding info on the M5OD-R1HD. how much does it share with the M5OD-R1? i would think that one could be a bolt in swap for the other. is this correct? are the input and output shafts the same?

was the HD the only manual transmission that was used behind the SOHC 4.0L?
what are the actual numbers for HP and Torque handling for this transmission or where can i find them?

how much would a HD tranny be worth in good working order?

what major differences are there if any between the two trannys?

stegomon · Sep 15, 2007

hd as in heavy duty?...i think there is only the r1 and r2...

wahlstrom1 · Sep 15, 2007

No, he's right, there is an HD version, used only behind the sohc engine. Not too sure what the differences are, aside from a bolt or two on the bellhousing. When I was looking into getting my tranny rebuilt, 3 different shops couldn't tell me any difference between the two, and couldn't come up with any different parts numbers between them.

-andrew

metalmacguyver · Sep 16, 2007

so do you mean that it wont be able to bolt up to a 4.0 OHV?

wahlstrom1 · Sep 16, 2007

It'll bolt up, but if my memory serves me correct there's an extra bolt hole on the housing and not a hole in the block for it.

-andrew

metalmacguyver · Sep 16, 2007

i did manage to find some more info over on explorerforum.com.
the first gear ratio is lower in the HD and supposedly the first and second gear syncros are more robust.

does anyone else know anything about these?

i found one in a junkyard in a wrecked 02 explorer. it seems to shift fine by feel. it would be a safe estimate to say that the tranny has 80K on it. what would a fair price be? i asked the yard owner and he wants 450 for it. that seems steep to me. i would think 300 tops. thoughts?

Jspafford · Sep 16, 2007

metalmacguyver said:
i did manage to find some more info over on explorerforum.com.
the first gear ratio is lower in the HD and supposedly the first and second gear syncros are more robust.

does anyone else know anything about these?

i found one in a junkyard in a wrecked 02 explorer. it seems to shift fine by feel. it would be a safe estimate to say that the tranny has 80K on it. what would a fair price be? i asked the yard owner and he wants 450 for it. that seems steep to me. i would think 300 tops. thoughts?

$450 is steep. You have no idea what condition it is in, and unless it was his personal vehicle, he doesn't either. Offer him what you feel it is worth, not more than $300 and go from there.

metalmacguyver · Sep 17, 2007

OK this is the conclusion that i have reached.

the M5OD-R1HD that is supposedly used in the explorers with the SOHC is actually the M5R4. these transmissions are completely different and while they are both mazdas and both bolt to the same engines, they share no parts.

The M5R4 was only found in 2002-2003 explorers.

one point of interest though is that it has a detachable bell housing. anyone got some ideas to make use of this....?

The M5OD-R1HD is the same thing as the M5OD-R1 except it has taller gear ratios.
The HD was found only behind the SOHC 4.0L.

http://rsgear.com/articles.asp
an amazing number of articles on manual transmissions in general and on specific transmissions aswell.

http://rsgear.com/articles/2002_11.pdf

the gear ratios
Gear M5OD-R1 M5OD-R1HD M5R4
1st 3.72 3.40 3.37
2nd 2.20 2.05 2.04
3rd 1.50 1.31 1.30
4th 1.00 1.00 1.00
5th(OD) 0.79 0.79 0.78
Reverse 3.40 3.40 3.40

Natedog · Sep 18, 2007

metalmacguyver said:
OK this is the conclusion that i have reached.

the M5OD-R1HD that is supposedly used in the explorers with the SOHC is actually the M5R4. these transmissions are completely different and while they are both mazdas and both bolt to the same engines, they share no parts.

The M5R4 was only found in 2002-2003 explorers.

one point of interest though is that it has a detachable bell housing. anyone got some ideas to make use of this....?

The M5OD-R1HD is the same thing as the M5OD-R1 except it has taller gear ratios.
The HD was found only behind the SOHC 4.0L.

http://rsgear.com/articles.asp
an amazing number of articles on manual transmissions in general and on specific transmissions aswell.

http://rsgear.com/articles/2002_11.pdf

the gear ratios
Gear M5OD-R1 M5OD-R1HD M5R4
1st 3.72 3.40 3.37
2nd 2.20 2.05 2.04
3rd 1.50 1.31 1.30
4th 1.00 1.00 1.00
5th(OD) 0.79 0.79 0.78
Reverse 3.40 3.40 3.40

Great info, thanks!

Strub1975 · Sep 20, 2007

From what i have researched metal is correct except that the 4.0 rangers have had the 3.40 gear sets since the 4.0 came out. all the other trannies had the 3.72 gear set.
there have been two gear sets for the M50D-R1 since the 4.0 was put in the ranger. this was done because there was no need for the lower gears since the 4.0 had more HP and torque

I am still trying to figure out the differences between the
M50d-R1 and the M50D-R1HD seems that there are limited resources on the HD trannies

Now the article on the M5r4 was great that is a whole different animal. basically the lengths of the shafts are swapped(the input is longer and the output is shorter) wich is pretty cool but I dont' really see an advantage of it to be honest ?? who knows LOL

nathanb · Apr 15, 2009

I'm also kinda lost! I own a 93 ranger SOHC V6. I'm needing (i think) a replacement. Mine got a clutch kit and slave cylinder. Installed it, but now all gears except 1st and 2nd engage. Iv read a few articles and seems that the tranny got low on fluid and seized 1st and 2nd together. Ive searched for others but let me tell you 'THE M50D-R1HD ARE HARD TO FIND!"
Would like to know however if the M50D-R1 will interchange

mjonesjr · Apr 15, 2009

The M50D-R1HD will bolt up to a 4.0 OHV and will NOT have an extra bolt hole. I installed an '03 M50D-R1HD in my '97 Ranger and there was no extra bolt holes.

AllanD · Apr 15, 2009

The M5R4 explorer trans is a different animal that goes with the
later semi-integrated T-case used in the IRS explorers.

The HD is the RANGER transmission.

If a trans alleged to be an "HD" doesn't have an "extra bolt hole" it isn't an HD.

One bolt on the SOHC engine needed to be relocated for timing chain clearance to the passenger side camshaft and the bolt boss was in the way

PErsonally I've never done more than lay my hands on an HD.

eventually... I'll get my hands on one and get to dig inside it
and I'll get back to everyone...

AD

mjonesjr · Apr 15, 2009

AllanD said:
If a trans alleged to be an "HD" doesn't have an "extra bolt hole" it isn't an HD.

The transmission I used on my '97 Ranger came off of rwenzing's '03 Ranger. I think there is no doubt that his truck was a 4.0 SOHC.

Sevensecondsuv · Apr 16, 2009

nathanb said:
I'm also kinda lost! I own a 93 ranger SOHC V6.

Unless you did a swap, you don't have a SOHC 4.0L. That engine didn't come out until 97 in the explorer and about 2001 in the ranger. What you have is an OHV (overhead valve) 4.0L that was introduced in 1990. As such, you also have an M5OD-R1 4.0L spec tranny, which should be abundant and cheap to replace.

Now if you did do the swap to put a 4.0L SOHC in, please tell us how you did it, because this is not a popular swap and we could all stand to learn from it. I personally am interested to know if you are using the EEC-IV system or swapped to the later EEC-V system from the SOHC donor vehicle.

Again, if you didn't swap engines, then hopefully this clears up some of your confusion. If you did swap, please tell us more!

M5OD-R1 vs. M5OD-R1HD

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