A4LD Failure, Looking at M5OD-R1 Swap

[chrisbronco2]

Hi everyone, I bought a 1990 Ford Bronco II 2.9 V6 4WD Automatic about a month ago. For a couple weeks it was losing about a pint of trans fluid every 2-3 days but shifting great as long as I topped off the fluid. A shop found trans fluid in the modulator valve and the vacuum line, replaced the modulator valve and blew out the line, and now it won't shift out of 1st gear. They did the band adjustments with no result and are recommending a rebuild or replacement. I'm kind of shocked because, although it was losing fluid, it was shifting great!

Everything I've read so far points to throwing the A4LD in the trash and swapping in a M5OD-R1, which sounds good as I prefer a stick shift. So my questions are:
1. Is there anything else they should try to fix my shifting problem short of a rebuild/replacement?
2. If I go the swap route, should I look for the M5OD in a junkyard or buy a reman unit?
3. What parts will I need in addition to the trans? Should those be new or salvage?

The shop hasn't done this swap on this vehicle before and I just want to make sure they have as much info as possible. Thanks! -Chris

 

[RobbieD]

1. Is there anything else they should try to fix my shifting problem short of a rebuild/replacement?

Mine wouldn't shift one time before I ditched the A4LD, and the governor in the tail shaft housing was sticking. Polishing it with a scotch pad fixed it. Mine is 2WD, so yours would be a bit more involved to get to.

2. If I go the swap route, should I look for the M5OD in a junkyard or buy a reman unit?

A donor truck would be the best route, mainly for all of the "little parts" you'll need.

3. What parts will I need in addition to the trans? Should those be new or salvage?

- Bare minimum
Manual pedal assembly.
Clutch, complete- pressure plate, slave cylinder, master cylinder, reservoir and line, throwout and pilot bearings.
Flywheel, with bolts..
Transmission. Shifter should come with it and grab the bellhousing bolts, too.
- Unknown
Drive shafts? I can't tell you on a 4WD A4LD to M5OD. I did a '90 Bronco II 2WD A4LD to FM132, and had to have a driveshaft made; M5OD maybe not.
Cross member? I don't know for a 4WD. On my 2WD the original cross member worked fine.
Starter? On my 2WD both transmissions used the same starter.
- Remaining detail items
Floor trim with rubber shifter boot.
ECM. The auto ECM will work, but it will be looking for shift solenoids that are no longer there; idle will be a little high.
Transmission wiring harness; will turn the wiring into "pug-n-play", instead of cut-n-splice.
Steering column for a manual trans. Minimum would be the column trim pieces to cover the converted original column. Some people, though, are perfectly happy just hack-sawing off the auto shifter.
Floor plate with manual opening; the blank auto floor plate can be cut instead.
PRNDL block off plate for the gage cluster.
Your parking brake should be serviceable.

It's not really a hard job to convert auto to manual on these old trucks. The job can be done as "functionable but not pretty" or it can be done so complete and correct that only the door sticker will give it away as a conversion. Having to pay for the labor may limit you on how far it goes. I can't imagine having a repair shop do this swap, but I hope that you're dealing with a good, straight shooting shop.

Another good reason going the donor truck route, as pulling the parts let's whoever is doing the work see how everything originally went together.

Look in the Tech section here on TRS, as I'm sure there's an article or two on the auto-to-manual swap.

Welcome to the site, and good luck!

 

[Shran]

Personally I would find another shop. Concerned that they may be a bit incompetent if it was fine before and suddenly not after they touched it - see this:

A4LD Vacuum Modulator Pin length

A few years ago a friend had her vacuum modulator replaced by a "mechanic". The next day she told me it was not shifting right & over revved on the 1-2 shift. I told her I thought he forgot put the pin back in. She took it back & he said the pin was in there & told her she needed a trans...

www.explorerforum.com

Makes me think that you need a second opinion. The A4LD is kind of a fragile beast but if you do decide to swap here's some more input:

A4LD & M5OD are the same length, no need to change driveshafts. Nice little bonus there.
Crossmember will also be reused.
Starter I'm not sure on - there is a difference between 4.0 manual and auto starters. IIRC the 2.9 starters were the same. Something like that anyway.
As far as the ECM, if you have to pass smog, and use an auto ECM, there will be codes present for the missing solenoids as Robbie mentioned. This may or may not affect your ability to pass smog if the check engine light is illuminated.

 

[chrisbronco2]

Thank you! It actually is now at a different shop because I felt like they weren't really interested in doing a lot of troubleshooting. I have mentioned to look for the pin in the vacuum modulator. In terms of a donor truck, I assume it needs to be a 2.9 4WD as well? What years am I looking for? Up to '97?

 

[RobbieD]

A 1989 to 1992 Ranger, or an '89 to '90 B2, with 4WD with 2.9 would be your best donor as far as everything matching.

The interior pieces needed run 1989 to 1994, but I can't say if the clutch pedals are the same on the '93-94 as it's a different body style, and maybe a different pedal mount to the firewall. 1995 started OBD2, which is an added wrinkle on the ECM compatibility. And '88 and earlier is a completely different interior, so those bits wouldn't be compatible.

The 2.9 may have been phased out as late as '92; I remember some overlap as the 3.0 came in but don't remember the details.

You will need an M5OD from a 2.9 OR 4.0, just to bolt up to the engine (because the bellhousing is not removeable). A 4.0 M5OD used slightly different gear ratios, the 4.0 used a larger clutch and flywheel, and the starters are different.


The vacuum modulator being replaced didn't even click with me, but that is very suspect and likely.

I'm really hoping that the second shop finds an easy fix for getting your A4LD shifting again. That would buy you some time, which would be better for you to get your ducks lined up, rather than trying to tackle a conversion "under the gun", so to speak.

 

[gw33gp]

89 4WD Ranger had a 2.9L with a Mitsubishi transmission. I know in 90 the 4.0 was available. I don't know if the 2.9 was after 89.

 

[scotts90ranger]

The 2.9L was an option through '92 and M5OD's were rare in 2.9L Rangers even through the end... a 4.0L would be a better bet as all of them had M5OD's

 

[chrisbronco2]

So in other words it might be tough to find an '89-'92 Ranger with the 2.9-M5OD combo? And the only issue with the 4.0-M5OD is that it's geared slightly differently?

 

[sgtsandman]

If you can wing it, I would get the engine wire harness and ECM for the manual transmission. Not every state is the same but some won’t let a vehicle with a check engine light pass inspection. Some garages won’t even pull it in the bay if the light is on.

 

[Shran]

So in other words it might be tough to find an '89-'92 Ranger with the 2.9-M5OD combo? And the only issue with the 4.0-M5OD is that it's geared slightly differently?

Not real common but yes the only major difference is the gear ratio. If you didn't know about the difference because we told you about it, you more than likely would never notice.

 

[RobbieD]

So in other words it might be tough to find an '89-'92 Ranger with the 2.9-M5OD combo?

Yes, unfortunately. You might get lucky, but parts get harder to find as time goes on. It's a 33 year old truck.

And the only issue with the 4.0-M5OD is that it's geared slightly differently?

Correct. But it's not enough to really make a difference. The main thing, is that the one-piece case bellhousing will bolt up to a 2.9 or 4.0 block. You won't be able to use an M5OD from a 2.3 (4 cyl) or 3.0 application.

If you can wing it, I would get the engine wire harness and ECM for the manual transmission.

You actually need only the small harness that runs down to the transmission. The main engine harness is the same for both auto or manual, and either small transmission-specific harness will plug into the main engine harness.


I converted my '90 Bronco II, and there's several ways that you can skin this cat.

You can source a good used or a good reman 4.0 spec M5OD.

You'll want to go all new on the clutch assembly, and it's best (in my opinion) to get a complete package from a quality source, like LUK (which was OEM, I think). You could opt to upgrade to the 4.0's 10" clutch (which will require a different starter) or go with the original spec 9" clutch (your current starter works with 9"). You'll need the appropriate flywheel in both cases. My $0.02 worth, is the stock 9" clutch is fine, unless you have, or plan to, upgrade the suspension and wheel size for more serious off roading (or drag racing). Small bonus: staying stock makes buying replacement parts in the future a little easier. All of my old RBV's are 2WD stockers.

You can source the "annoying small parts" from one or more junkyard donors, or buy new. Instead of a complete pedal assembly, the manual's clutch/brake shaft can be slid out of the mounting bracket to replace the auto's brake-only. That part, along with a good manual steering column, shouldn't be that hard to find. Same for a manual ECM, or you can buy reman on that.

Any questions, just ask. With research and planning it's not a hard job.

 

[chrisbronco2]

This is great information, I really appreciate it! I would like to go slow and make sure it's done right, so I'd like to at least try to get the current transmission shifting again. The shop is going to check the vacuum modulator and band adjustments that the previous shop did. Any other ideas/things to check? It basically won't shift beyond 1st gear now, even when I shift manually, but was shifting totally normally before those two things were done (although it was losing tons of fluid).

 

[RobbieD]

I really hope that the new shop finds that it's something simple, and gets your truck back going for you.

Then you will have the time to line up your conversion parts, and get better prepared.

I liked the A4LD, I just got tired of it breaking. But I like manual transmissions better, and changing over made driving the B2 even more fun than it already was.

Good luck!

 

[chrisbronco2]

I'm slowly gathering parts. Would this work for the clutch pedal assembly? Haven't found earlier than 91 so far. Are there additional parts needed for this?

- Bare minimum
Manual pedal assembly.
Clutch, complete- pressure plate, slave cylinder, master cylinder, reservoir and line, throwout and pilot bearings.
Flywheel, with bolts..
Transmission. Shifter should come with it and grab the bellhousing bolts, too.
- Unknown
Drive shafts? I can't tell you on a 4WD A4LD to M5OD. I did a '90 Bronco II 2WD A4LD to FM132, and had to have a driveshaft made; M5OD maybe not.
Cross member? I don't know for a 4WD. On my 2WD the original cross member worked fine.
Starter? On my 2WD both transmissions used the same starter.
- Remaining detail items
Floor trim with rubber shifter boot.
ECM. The auto ECM will work, but it will be looking for shift solenoids that are no longer there; idle will be a little high.
Transmission wiring harness; will turn the wiring into "pug-n-play", instead of cut-n-splice.
Steering column for a manual trans. Minimum would be the column trim pieces to cover the converted original column. Some people, though, are perfectly happy just hack-sawing off the auto shifter.
Floor plate with manual opening; the blank auto floor plate can be cut instead.
PRNDL block off plate for the gage cluster.
Your parking brake should be serviceable.

It's not really a hard job to convert auto to manual on these old trucks. The job can be done as "functionable but not pretty" or it can be done so complete and correct that only the door sticker will give it away as a conversion. Having to pay for the labor may limit you on how far it goes. I can't imagine having a repair shop do this swap, but I hope that you're dealing with a good, straight shooting shop.

Another good reason going the donor truck route, as pulling the parts let's whoever is doing the work see how everything originally went together.

Look in the Tech section here on TRS, as I'm sure there's an article or two on the auto-to-manual swap.

Welcome to the site, and good luck!
[/QUOTE]

 

[Shran]

Rare?!?! Ranger pedals are RARE?? That seller is a total chode. Those are not anywhere near hard to find nor are they expensive. Maybe $20-30 is what I would pay for a pedal assembly at a junkyard. '89 to '94 are all the same - Ranger, Bronco II or Explorer. Actually you don't even need the bracket, just the pedals themselves, they can be swapped without removing the dash... kind of a pain but doable.