94 transmissions questions

[Bubbax]

Hello
I have a 94 Ford Ranger
Extra cab with a 4.0 litre engine,
M5OD-R1 5 speed transmission
Rear axle ratio 3.08
175,000 miles
1st and 2nd syncros seem to be worn out > Shifts fine on cools days for a few miles then 1st and 2nd grind unless I am real careful shifting.
I can shift into 1st without grinding if I apply the clutch for about 10 seconds
No problem shifting into reverse 3 and 4 grind every so often fairly rare.

I an considering replacing the transmission with an M5OD-HD from an newer Ranger.
My concern is the difference in 1st, 2nd and 3rd gear ratios.

Gear M5OD-R1 M5OD-R1HD
1st 3.72 3.40
2nd 2.20 2.05
3rd 1.50 1.31
4th 1.00 1.00
5th(OD) 0.79 0.79
Reverse 3.40 3.40

4.0 litre
3.08 rear rend

The OHV engine is supposed to have 40 more hp

I occasionally pull a 15 foot boat with no problem

Will I notice much of a difference with the lower gear ratios?

Also will there be a problem connecting the speedometer ?

Is it difficult to rebuild the M5OD-R1 transmission?
I am mechanically inclined and I can follow directions. Fair amount of engine experience.

Thanks in advance
Bob

 

[RonD]

I think you were looking at the 3.0l/2.3l M5R1 specs for gear ratios, they have the 3.72 1st gear

The M5R1 for 4.0l OHV and M5R1HD for 4.0l SOHC have the same ratios
So you will be fine with later model M5R1HD
The HD has an extra bolt hole on bell housing and the shifter is different, so get the whole trans, shifter and boot

Article here shows the differences: https://www.therangerstation.com/tech/how-to-replace-a-m5od-r1-with-a-m5od-r1hd/

Rebuilding manual trans is just a step by step process, there are some bearings to press in and out but you can usually work that out if you read a bit on DIY work arounds, lol

 

[Bubbax]

Hi Ron
Thanks for the quick reply. That is great information for me. The tranny is going and the clutch is following.
Do you know if there are any issue with the speedo? I read the article you sent about swapping the trans, that will be a great help.
Thanks again
Bob
Turns out it is a 94 not a 95 I do not think that will make a difference

 

[RonD]

Yes, it wouldn't matter
The 1997 and older 2WD transmissions, manual or automatic, have a hole in the rear transmission housing for a speedometer cable hook
And a speedometer DRIVE gear on the output shaft inside

1998 and up have no hole in the housing for speedo cable

2WD Automatics have the speedo drive gear machined into the output shaft, so the gear is there in all years up thru 2011

Manual transmissions have a changeable speedo drive gear, so a separate removable part
The 2WD M5R1 or M5R1HD output shaft still has the place to mount a speedo drive gear in all years up thru 2011

If you look at this listing: https://www.ebay.com/itm/173961605312
That's the 2WD M5R1 output shaft, and near the end(long spline for drive shaft), you will see a smooth area with a hole/cup for speedo gear mount
A little ball bearing goes in that hole/cup

Speedo gear slides over it, gear with slot for ball bearing seen here: https://cdn3.volusion.com/ymcqg.kvqok/v/vspfiles/photos/M5R1-169W-2.jpg?v-cache=1605883202

Since you have a pre-1998 2WD M5R1 you can remove your rear housing and ball bearing with gear to install all on the newer model M5R1HD

There are 8 bolts to remove, and rear housing pulls off, I would replace the rear seal and if you can find one the gasket but many came with no gasket, Ford just used black silicone(RTV) like on the rear axle housing

 

[Bubbax]

Hi Ron
Thanks again for the very helpful and detailed answer.
Just need to find a transmission now. Should not be to hard .
Bob

 

[Bubbax]

Hello
Turns out finding a a M5R1HD has not been as easy as I thought it would be, I have found a few 4 wd but no RWD. Can you tell me If it is very difficult or even possible to convert a 4wd drive tranny (remove the transfer case) to a rwd tranny? Thank you Bob

 

[RonD]

You don't want an M5OD-R1HD, that's just for 2001 and up 4.0l SOHC engines, you could use one but no speedo hook up
"HD" means there is an extra bolt hole in bell housing, it does NOT stand for "heavy duty", just FYI

You want any M5OD-R1(M5R1) 1990-1997 RWD from a 4.0l engine

Yes, you can convert an M5R1 4WD to RWD since you already have the RWD output shaft and RWD housing on the old trans

The 4WD transmission will come with shorter output shaft and housing, you will remove both and install your longer output shaft and housing

There are a few M5OD-R1 disassembly videos so you can see what is required


Its odd though, I thought 4WD were harder to find

 

[Bubbax]

I understood the M5OD-R1HD had more substantial 1st and 2nd gear syncros than the M5ODR1 . Also the HD could be bolted onto the 1994 4.0. That is what is failing on my old transmission.

 

[RonD]

Mazda redesigned 2nd gear synchro in mid-2000's, want to say 2003/4, and that one multi piece synchro alone was $250, lol
Thread here on that: https://www.therangerstation.com/forums/index.php?threads/m5r1-rebuild-kit-identification.189292/

So on general principle I would avoid buying the R1HDs if you can use an R1

All the M5R1s were reliable and long lasting, my 1994 4.0l M5R1 is still OK after 400k, just a good manual transmission design
To have any year(1988-2011) fail is an oddity, but at close to a million + out there some will fail

There has been no noticeable longevity difference of an R1 vs an R1HD, they both seem to last a long long time
So I certainly wouldn't hold out for an R1HD if an R1 was available