B2 Manual Trans Change

ldbill39 · Feb 24, 2010

I have a 2WD B2 with a bad FM146 Trans, I am looking to change it over to a Mazda M5R1. What if any changes will I have to make? Any info would be great, since I need to get this on the road.

adsm08 · Feb 24, 2010

I think that the M5 will just bolt in place of the 146. Its the 145 that gives people trouble for this swap.

AllanD · Feb 24, 2010

You WILL have to replace the (removeable) Floor plate and shift boot.

You MAY have to replace the T-case shifter (if you have a manual T-case)

there were three different shifters for the 13-50 in 1988-90
and only ONE of them fits the Mazda trans.

AD

ldbill39 · Feb 25, 2010

Actually, I'm putting a 2wd M5R1 in, and removing the FM146 and dummy transfer case. I have been told that it should just bolt in, and have a ranger drive shaft shortened.

spdcrazy · Feb 25, 2010

not sure about a 2wd version, but on my tk5 to m50d swap i had problems with the clutch line as well. and tranny xmember. maybe someone can chime in here for ya..

good luck! and outta curiousity, whats the reason for the swap?

AllanD · Feb 26, 2010

spdcrazy said:
not sure about a 2wd version, but on my tk5 to m50d swap i had problems with the clutch line as well. and tranny xmember. maybe someone can chime in here for ya..

good luck! and outta curiousity, whats the reason for the swap?

Tha's because you have an '87.

The '88 already has the new ('88-92) style clutch line and slave cylinder.

AD

spdcrazy · Feb 26, 2010

AllanD said:
Tha's because you have an '87.

The '88 already has the new ('88-92) style clutch line and slave cylinder.

AD

good call...

another good call, i'm in flagstaff buddy, if ya need a second hand let me know.

macd7919 · Mar 1, 2010

I jut swapped my FM146 for a MD05, I must have got a 4wd version (you mention 2 different versions) as I used the transfer case and it bolted straight up to the oem driveshaft. Why not just get a 4wd version and use your dummy transfer case and not worry about getting a driveshaft made? Then if you ever want to convert to 4wd (which I also did) then you are halfway there. (Btw, the step by step for converting to 4wd ins in the tech resources section here).

As far as the shifter you will need to cut the floorplate, easy work with a dremel.

ldbill39 · Mar 1, 2010

Hi, thanks for the info Allan, the reason I'm staying with 2wd is that the BII won't fit my whole family to go off-road. I'm kinda more interested in the gas mileage, since I have a 4wd Expedition, that only gets about 10-12mpg driving around Prescott. I take my granddaughters to school and daycare, and it gets expensive driving the bigger truck. I have been told the BII gets 22mpg around town, which is even better than my F250 that gets 8mpg. The trans shops have told me the FM146 wasn't all that great, but the M5R1 is better and a lot stronger. I get it back this friday, so if anyone needs a FM146 w/dummy transfer case, let me know.

ldbill39 · Mar 16, 2010

M5R1 Trans

Hi all,
The trans got installed and was a little tight going in where the firewall transitions to the tunnel. The newer trucks might have had a relief area in the transition to compensate. But once past that, the trans bolted in just like it was meant to be there in the beginning. The only thing left to do is get the drive shaft shortened. So far it has been a fairly easy conversion, you just have to remember to get "all" of the parts from the donor vehicle, or another trip the the JY will probably be in order.

ldbill39 · Mar 31, 2010

Trans works great, now if I can only keep it running after it warms up. I have a bad TFI, hopefully that will solve my problem.

spdcrazy · Mar 31, 2010

glad it all worked out for ya!

ldbill39 · Apr 5, 2010

Put the new TFI in it, and it did the same thing, quit running after it warmed up. Just for fun I felt the inertia switch, which is right under the heater core, it was HOT. I disconnected it and jumped the wires, and it hasn't had the dying problem since. I have done automotive for over 25 years, replaced many inertia switches, but never had one that would flake when hot, go figure.

B2 Manual Trans Change

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