Hi, brand new user here. I own a 1985 f150 single cab and it has the garbage 3speed+Overdrive.

Trans is shot and leaking everywhere and has a bad input shaft bearing.

looking to swap it for an M5ODR2 and I’ve been patrolling these forums for info on what I’m missing.

i know I need the tunnel cover for the interior, and the slave cylinder mounted and maybe to move my crossmember back. (Driveshaft length is good and clutch will work)

is there anything I need to know before doing this?

I have extensive mechanical knowledge and am taking college classes for it, just don’t know much about swapping stuff into other stuff.

Thanks!

 

Best thing to do is go to www.rockauto.com or some other site like autozone, napaonline, etc. and look up your truck and get the part numbers for the clutch and the flywheel and any other parts like that, and then look up the truck that the donor 5 speed came out of. If the flywheels come up the same part number, then you know you can use the old flywheel. If not, make sure to get the flywheel when you get the trans. Same with the clutch, although you will probably want to get a new clutch. Most of the M5OD transmissions had the concentric hydraulic throwout bearing. The one time I looked they were sort of expensive. Maybe your donor has been replaced before and is in good shape. On the one I was messing with they offered just the bearing as an option to replacing the whole thing.

Check out any wires going to the old trans, like reverse light wires and possibly neutral safety wiring. On the donor trans, if it has any switches on it, try to get the plugs and a little bit of the wiring with it so you can splice in your wiring if you need to.

I believe the 5 speed is going to take a automatic transmission fluid, while your old trans took gear oil didn't it? Check that out, you do not want to put that thick stuff in a trans designed for auto trans fluid.

 

I have done a couple M5OD swaps into Bullnose trucks.

Need to know if your truck is a 2wd or 4x4, and when you say 3speed+Overdrive, are you referring to the AOD Automatic, or the 4spd manual with OD?

You'll want the 5spd tunnel cover, yes. You can get by without it, but better if you have it.

If 2wd, you'll want an M5OD specifically from 1988-1991 if you want to retain your factory cable driven speedometer. If 4x4 it doesn't matter, so 1988-1996 M5OD will work.

5spd crossmember if you can get it, and the plug/pigtail for the reverse connector on the trans, but you can buy these plugs new for cheap anyway.

If you're switching from an auto to manual, you'll need the hydraulic clutch pedal set from a 1984-1986 Bullnose. You'd also need a new flywheel, pilot bearing, and a starter for a manual transmission.

If your truck is already a manual, all you need is the hydraulic line to connect to the concentric clutch slave cylinder.

Some other odds and ends...but they're the major items...

 

Dave your flywheel information is off a little I believe.
The post starter has a 300 six but if he gets the trans from a truck with a v8 the flywheel will not work as the balance will be off.

My 300 has a 10" clutch disc but they say the flywheel may be drilled for 11" clutch disc.
I dont know if mine is as mine was all back together and did not know about the 2 sizes.
So checking that part will may not pan out right.

Because of the 2 size disc I dont think you can even look up clutch kits or even just the disc either?
Once you know what size disc the flywheel will take then you need to find what the spline count is of the input shafts of the old & new transmissions so you can get a disc to work with the set up. My guess is to go with the new transmissions clutch kit if the flywheel will take it.

You need to check the pilot bushing / bearing between the 2 transmissions as the input shaft side could be different.

On the slave cylinder you are on your own as my 81 uses linkage.
Keep us posted on the swap.
Dave ----

 

No Sir. I am refering to the Absolute garbage 3 year offered in the bullnose 3 speed plus large overdrive gear. Its a weak Toploader that has hundreds of problems. Mine is on its way out and I dont trust my truck to get me the 20 miles to college and back on the highway so I need it swapped soon. (its 2wd)

The RUG SROD 3S+OD was offered from 83-85 in F150 2wds and some F100s. Go look on gary's garagemahal for info. Literally just found you on an SROD post.

 

So you’re saying that third gear is overdrive or is there another gear after third that is overdrive? Another gear after third would make it a 4 speed.


In the first post you mentioned mounting the slave cylinder. The slave cylinder on the Mazda M5OD-R2 transmission is inside the bell housing.

 

Interesting. In 1985 it should be the TOD if it's the 4spd with OD. I didn't think the SROD was around that long. If it's an SROD, the shifter back close to the bench seat. If it's the TOD, it is an aluminum transmission and the shifter is closer to the dash like normal.

Anyway...

If you're doing an M5OD swap, you can re-use your flywheel and starter, so you're all good there.
The M5OD came with an 11" clutch, so you can get your flywheel surfaced and swap in the larger clutch.
For 2wd, you'll want an M5OD from a 1988-1991 F150/F250 pickup.
You can use your existing clutch master cylinder, or replace with a new Bullnose master, and just connect a 1988-1991 clutch hydraulic line to it.
Driveshaft...I don't know the length of the 4spd, so you might have to grab the driveshaft from the donor 5spd truck if available.

If you already have a hydraulic clutched 2wd manual Bullnose, an M5OD swap is pretty easy.

 

My 1984 F150 had a 10" clutch, but the factory flywheel was also drilled for an 11" clutch. I had the stock wheel surfaced and installed an 11" clutch when I did my 5spd swap.

I thought they were always drilled for both 10" and 11" clutches, but I don't know that for certain. All of the early 80's half tons I looked at had 10" clutches anyway.

 

thank you so much!! That seems to all check out! my driveshaft lengths between the transmissions are within 1/8th of each other. Also apologies for the confusion, my Chilton manual says 3speed+OD and every rebuild kit I come across says “RUG SROD/TOD 3SP+OD” so apologies. also my truck is model year 1985, the in-line 6 is from 82 and the transmission from 83. All verified to be original stock and never rebuilt.

 

That 3 + OD drives me nuts. Half the time people think of the T85 etc BW transmissions with the R10 and R11 electric ODs on the tail. Those were available possibly as late as '71, maybe longer. THOSE are a 3 speed + OD.

So Ford uses the same term for the 4 speed OD. I had the iron one with the external shifter. No real trouble with it but the gap 2nd to 3rd was a pita.

Check your firewall where your clutch master mounts. A lot of '85s trucks flex when new, and time and rust can end up with a crack--makes shifting hard and getting into gear at a stop almost impossible.

 

firewall is good! No need to brace it or anything, my clutch master does not actually exert much force when I hit the clutch. My RUG is the aluminum toploader style. 2nd to 3rd isn’t bad on mine it just has a bad input shaft bearing so it refuses to go in gear sometimes. I can’t wait to get the Mazda and forget about these weird 3 year issues. Thanks for the reply!

 

Got my transmission! Going to pull the 4OD soon and once I get my intake and exhaust manifolds everythingll be alright and it might just be fast.

the M5 i grabbed is completely rebuilt, like factory new inside. Ill keep y'all updated.

 

Congrats. It is 2wd, correct? What year is the M5OD? Does it has a cable speedo drive?

 

Yes it’s 2WD and has the spot for the speedo (88). Trying to wire in a tach today and waiting for parts is getting me away from any trans work as of currently soo time to chase cut wires down tomorrow

 

Trans is in, had to flatten a locator pin on the block and trans so it would fit but it bolts right up and I had to frame drill for the crossmember.

but it whines like hell and drives like hell so I love it, truck is damn fast now!