Trans Swap - Is it worth it?

[mnewman]

Hi guys. I have an '86 BII with the FM145 and BW 1350 tcase. The truck was originally an automatic but the previous owner swapped it with the FM145 but never finished the linkage for the manual shifter. I'm having a hard time find the last lever off the BW1350 to make it work right. Also the current trans whines really loud in 3/5 and of course the ole FM145 supper sloppy shifter. No sure if the whine is normal.

However I found an '88 BII with what looks to be the mazada trans and manual floor shift on the 4x4.

Do you guys think its worth a $500 parts truck to swap in the mazda trans? Plus I would have all the correct linkage to make the floor shift work. Does anyone have any idea what I would need to modify on the '86 to make the '88 trans/tcase work?

Another thought, '89 was the first year for the D35 in front, correct?

 

[Shran]

The whining noise is not normal, great indicator that it's worn out or been run low on fluid.

An '88 would have come with an FM-146 from the factory which looks more or less identical to what you have now. Make sure that it actually has the Mazda M5OD trans... someone would have swapped it in... an FM-146 is NOT an upgrade from what you have now, it's more or less the same transmission. IF it in fact has an M5OD installed and there are other usable parts, $500 for a parts truck isn't awful I guess. It's the far upper end of what I'd pay.

You will not need much to make the newer trans work, main things that come to mind are both driveshafts (M5OD is longer) and the newer slave cylinder and clutch hydraulic hose. Pretty easy swap.

The D35 wasn't available until 1990.

 

[mnewman]

Thanks for the response. I'm over a hour away so my info is from pictures. Does the FM146 have a straight shifter lever or is it angled like the FM145? I asked for a pic of the door tag as well.

 

[Shran]

No, it's angled, BUT, the rubber boot covers it up on '88 and '89 so it looks like a straight M5OD shifter. What you really need is a view of the transmission itself... if it's got a metal oil pan bolted on the bottom, it's an FM145/146... if there's no pan at all and the bottom is rounded with ribs on it, it could be an M5OD. It could be something else entirely... a TK 4 or 5 speed, it's so hard to say without seeing it. These trucks are often cobbled together with parts from various other years!

 

[mnewman]

No, it's angled, BUT, the rubber boot covers it up on '88 and '89 so it looks like a straight M5OD shifter.

oooohhh I didn't know that.

 

[mnewman]

The seller was nice enough to send me a pic of the door tag. Big fat "D" on there for the FM146. Looks like my search continues.

Thanks Shran.

 

[Shran]

No prob. Using an FM146 isn't a big deal as long as it's in good condition. And because of their nature, it's easier to find worn out ones...could be why that rig got parked, maybe it's got a bad trans too!

If you're pretty mechanically inclined and have a good set of tools, your FM-145 isn't super hard to rebuild. I just did one and have another torn down on my bench right now... even after a bearing kit, new input shaft and some gears I still only have like $350 into it. If you go that route, I probably have the piece you need for your t-case as well.

 

[mnewman]

I've always wanted to rebuild a trans but they're scary without ever having done one before.

I'm back to fixing what I have. I'll keep an eye out for a donor truck but most everything around here has already been scrapped or too good (expensive) to take apart. So if you wanted to sell the lever off the 1350, I'd be interested. Hopefully I can change the fluid and get the summer out of the FM145 in the truck now. I need to put a motor in my 2003 ext cab which is likely going to be the dedicated trail rig.