'88 4cyl 4x4 M50D-R1 locked up...

[RangerinVA]

I have an '88 4x4 2.3L Ranger that the tranny locked up on today... (At 70 MPH on the Interstate! Bit of a wild ride!) After cleaning my shorts and trailering my broken ride home, I'm considering how to proceed... if, when I tear the tranny down, I find that the main/output shaft is damaged beyond repair, is there a source for this part? I'm not finding one... and, if there is no source for new 4WD ones, am I assuming correctly that the small V6 tranny (guts, not case) will interchange? They appear to use the same internal parts... Any help/guidance will be greatly appreciated.

 

[RangerinVA]

It is an M50D-R1. I see where there's some debate on this tranny coming on '88's, but this is definitely that transmission.

 

[Shran]

If it's a 4 cylinder, it has an M5OD. Just about any part you need is still available, just takes a little searching sometimes. V6 guts will work, 4.0 transmissions have different gear ratios, 2.3/2.3.0 transmissions have what you have now.

 

[NakedDucks]

I have a 2.3 M5OD I won’t be using. (I bought it for the case, as I am writing a tech article.). It’s 2wd, but in perfect working order.

If you care to drive, we can take the guts from it and your trans and send you home with a good working transmission for your truck, ready to install.

 

[RangerinVA]

If it's a 4 cylinder, it has an M5OD. Just about any part you need is still available, just takes a little searching sometimes. V6 guts will work, 4.0 transmissions have different gear ratios, 2.3/2.3.0 transmissions have what you have now.

Thanks, that confirms what I've learned so far. The only part I've not been able to locate new/reman so far is the main/tailshaft for 4WD applications.

 

[RangerinVA]

I have a 2.3 M5OD I won’t be using. (I bought it for the case, as I am writing a tech article.). It’s 2wd, but in perfect working order.

If you care to drive, we can take the guts from it and your trans and send you home with a good working transmission for your truck, ready to install.

I appreciate the offer very much, but my understanding is it's the main/tailshaft that is unique to 4WD trannys.
Haven't even dropped and torn down the gearbox yet, so not sure what's broken. I'm just trying to gather as much info ahead of time so when I do dive into this I'm as knowledgeable as possible. Thanks again!

 

[Shran]

Thanks, that confirms what I've learned so far. The only part I've not been able to locate new/reman so far is the main/tailshaft for 4WD applications.

Might have to find a junkyard donor or two, especially if you're going to build it yourself. It helps to have a couple extras for parts or just to look at for order of assembly.

eBay, Rock Auto, Cobra Transmission, Zumbrota/USA Standard Gear are good sources for parts

 

[NakedDucks]

I can use the mainshaft out of your trans to rebuild a good one.

 

[RangerinVA]

We have several 2WD trannys in house, mine is the only 4WD. Gonna try the rebuild ourselves. We've worked on TopLoader 4 speeds and T5's, hoping this won't be too different. Appreciate all the info!

 

[scotts90ranger]

The M5OD is pretty simple to work on, kinda tricky to get some of the front parts out since they have to be turned right to get out the hole (that should hopefully make sense when you get there... it's been 10 years since mine was apart) but simple... Being locked up, who knows what the problem would be...

 

[Shran]

I hope your input and main shafts have not welded themselves together. I've seen that happen several times when they run low on fluid. It's very difficult to tear down... In every case, the main shaft was junk because the pocket bearing had fused to it. Fortunately it's pretty easy to find parts for these.

 

[RangerinVA]

Ok, several weekends later I'm reassembling the tranny. It was the input shaft main bearing welded to the shaft. I've gotten all new bearings/races professionally pressed onto the various locations, put the tranny back together per the various manuals and diagrams I've collected, torqued the front bearing retainer on per the spec (nominally 18 lb-feet) and the tranny is so tight it won't rotate by hand... any ideas?

 

[RangerinVA]

New input shaft as well, of course.

 

[RangerinVA]

 

[RangerinVA]

This is what came out...