‘88 ranger 5.0 swap 4x4 transmission blew (help needed)

[Fiveowen]

The Mitsubishi fm146 blew in my ranger this weekend… I cannot find another one to replace it for the life of me… I’m looking into swap options. I heard that the Mazda transmissions can get tight but I have a 3 inch body lift I’m sure that’d help a little bit. I would like to retain 4x4 as well. Looking for advice on what direction I should go in and what’s involved anything helps, thanks, Owen.

 

[fastpakr]

Could you give a little more background?

It's hard to tell - do you already have a V8 swap with an adapter to the FM146, or are you considering a swap because the trans ble behind the stock motor?

 

[Fiveowen]

Could you give a little more background?

It's hard to tell - do you already have a V8 swap with an adapter to the FM146, or are you considering a swap because the trans ble behind the stock motor?

The 5.0 is already in there with an adapter and bellhousing for the fm146

 

[fastpakr]

I would strongly encouraging losing the adapter and switching to a full size transmission. It'll involve changing driveshaft lengths, but you'll end up with a unit designed to work behind the V8 rather than one that was marginal behind the V6.

 

[RonD]

Welcome to TRS

Yes, the FM146 can't handle V8 torque/power
Neither can the BW1350 or 1354 transfer case, so it will be next

Best option is an M5OD-R2(M5R2) 5-speed with transfer case, from a 1997-2003 F-150 4x4 with 4.2l V6
The 4.2l V6 has the same bolt pattern as the 302 V8

You can use earlier 302 manual 4x4 transmissions and transfer cases, but the shifters come up thru the floor farther forward, not a big deal as you can heat and bend the shifter to clear the dash, and make a custom floor plate

The 1997-2003 M5R2 shifters are at the same place as FM146

 

[Fiveowen]

Welcome to TRS

Yes, the FM146 can't handle V8 torque/power
Neither can the BW1350 or 1354 transfer case, so it will be next

Best option is an M5OD-R2(M5R2) 5-speed with transfer case, from a 1997-2003 F-150 4x4 with 4.2l V6
The 4.2l V6 has the same bolt pattern as the 302 V8

You can use earlier 302 manual 4x4 transmissions and transfer cases, but the shifters come up thru the floor farther forward, not a big deal as you can heat and bend the shifter to clear the dash, and make a custom floor plate

The 1997-2003 M5R2 shifters are at the same place as FM146

Sweet, thank you so much for the info. I’ve got a couple more questions based on some other things I’ve read. Will I lose my speedo when swapping to the m5r2? What flywheel and clutch would I need? What work has to be done to the clutch mechanism? Hydraulic swap etc? Thank you.

 

[RonD]

1988 FM146 should be hydraulic clutch, so is the M5R2, flywheel is the same just used M5R2 pressure plate and slave, may need new master to match quick connect fitting, or at least the hose part

Yes, after 1997 the speedo cable drive was removed from 4x4 Transfer cases
So maybe use an earlier model transfer case with speedo cable hook up
There are/were adapters to used the V8 transmissions with BW1350/1354 transfer cases but as said it will be the next to go with V8 power

 

[Fiveowen]

Okay sweet thank you for the info, is there anything else I should know? Also fitment wise I should be good right. I’ve got a 3 inch body lift? I have access to a welder so I can modify the crossmember if I need to… also I’ve got 3.73 gears and the m5r2 has shorter ratios than the fm146 and I already am at 3k rpm at 55mph. My plan is to do a 3.08 8.8 in the rear what are some good ways to source a 3.08 for the Dana 28 in the front?

 

[RonD]

Front and rear driveshafts will change, connections and lengths, depending on transfer case used

The ratios are about the same except for 1st
.....FM146.....M5R2
1st: 3.769.....3.90
2nd: 2.210.....2.25
3rd: 1.516.....1.49
4th: 1.00......1.00
5th: 0.812.....0.80
Rev: 3.40.......3.39

This is a good calculator to see what ratio and tire sizes do to speed: https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

3.73 with 32" tires, at 2,500rpm in 4th(1 ratio) = 63MPH
In 5th (ratio 0.8) 77MPH

3.08 ratio in 5th would be 96MPH, lol, wouldn't want to be in the truck with you at 96MPH
Nothing personal

 

[Fiveowen]

Front and rear driveshafts will change, connections and lengths, depending on transfer case used

The ratios are about the same except for 1st
.....FM146.....M5R2
1st: 3.769.....3.90
2nd: 2.210.....2.25
3rd: 1.516.....1.49
4th: 1.00......1.00
5th: 0.812.....0.80
Rev: 3.40.......3.39

This is a good calculator to see what ratio and tire sizes do to speed: https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

3.73 with 32" tires, at 2,500rpm in 4th(1 ratio) = 63MPH
In 5th (ratio 0.8) 77MPH

3.08 ratio in 5th would be 96MPH, lol, wouldn't want to be in the truck with you at 96MPH
Nothing personal

Thank you, maybe my tach and Speedo are off from the last guy who did the swap, but 77 at 2500 sounds perfectly fine for me thank you I would not want to be in that thing at 96mph either LOL I think im gonna go the m5r2 route I’ll update this thread with some pics when its done thank you

 

[Josh B]

When you get it done take a drive on a highway with mile markers and test it ten miles to see how close it comes

 

[Fiveowen]

Front and rear driveshafts will change, connections and lengths, depending on transfer case used

The ratios are about the same except for 1st
.....FM146.....M5R2
1st: 3.769.....3.90
2nd: 2.210.....2.25
3rd: 1.516.....1.49
4th: 1.00......1.00
5th: 0.812.....0.80
Rev: 3.40.......3.39

This is a good calculator to see what ratio and tire sizes do to speed: https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

3.73 with 32" tires, at 2,500rpm in 4th(1 ratio) = 63MPH
In 5th (ratio 0.8) 77MPH

3.08 ratio in 5th would be 96MPH, lol, wouldn't want to be in the truck with you at 96MPH
Nothing personal

Hi Ron, I’ve tracked down a couple possible m5r2’s that will work for me… only problem is I have only found the transfer case from the same year f150 with the 4.6 v8 is the transfer case the same can i make it work? Thanks, Owen.

 

[scotts90ranger]

The transfer case you want was offered in the same years, '97 through '03, it's as compact as a full size transfer case gets, the downside is the rear output is slip spline and you would have to do some work to driveshafts like mentioned above