1947 Farmall M Episode 16: Troubleshooting/Grand Finale

Hello all!

First of all I want to give a big THANK YOU to all who have helped during this project (although it is far from over and I am sure I will still have many more questions). Today, due to everyone's patience and help, I finally got the M to breathe under it's own power after who knows how many years. I spent quite a bit of time troubleshooting a lot of things that I KNEW I had right (but better to double-triple check them), I spent so much time doing that, the most obvious (and easiest) was overlooked. I believe that 99% of my problem was the fact that the spark plug wires were out of order. Once I had it running, I started playing with the sequence and as I moved a wire it started to smooth right out. After a couple tries, I had it purring like a kitten.

Due to no sleep today (which is typical for me as an overnighter), I'm going to have to head over Friday again to retorque the head, get the tractor warm again, and readjust the valves. (Should the head be retorqued while warm, or should I do it prior to warming up for the valve reset)? I suspect that is where the hissing sound developed today after the tractor ran a while and was good and warm. From there, then, I'm going to flush the rear end and add new oil. I'm assuming it is both low and old oil in there causing a lot of the whine (and the fact that there are 70 year old gears in there). Once cleaned and topped off with new fluid it should operate well. Only thing I can see right off the bat is it needs at least one new brake band. Good thing is I don't have any leaks yet from any of the engine gaskets or connections (or the radiator) which I was really skeptical about after I took on repairing/soldering the side straps. Even the water pump isn't leaking a drop.

If anyone else has any other pointers or suggestions, I am very open to ideas. I've been coming to these forums since 1998 at the age of 12, and have sure learned a lot from many of you. Sure does feel good to be part of such a widespread and helpful group of people. I tried to post as much as I could in all of the videos I have made, and I sure hope someone else finds help in what I have put out there. I made my own mistakes, though, that is for sure.

Enjoy, and again.. Any pointers or suggestions please let me know. Otherwise, a retorque and valve adjustment is next on my list.

1947 Farmall M Episode 16 Troubleshooting and Grand Finale

Maybe two suggestions. I cannot see that far, but do you have a glass jar on the air pre-cleaner? It don't work otherwise. Other thing, I'd recommend a new spring under the seat. Old ones snap and drop you off the back. Ebay has them.

Ken,

Great job on the old m if I were you I would throw those junk gauges away they are cheap and have had nothing but trouble with them and that m should have more oil pressure should peg the gauge to the right I have least a dozen m's and they all peg the gauge make sure it has 9 quarts of oil too
Think it's precision gauges out of Illinois they are making quality gauges

My M's and super M's and B peg the needle with oil pressure and stay there.

Don't feel bad. I did that once too where I had the plug wires in the wrong spot.

Some gear noise is normal as the gears are straight cut spur gears.

Diagnosing trans/rear end noise over the internet is very tricky since "noise" is a subjective term. Rough bearings will make more noise than gears and the sound will modulate at the same frequency as the gear mesh. Bearings that are well worn but not rough or corroded will actually make for a fairly quiet transmission.

The pilot bearing and input shaft assembly are usually the most worn. The flexible coupling between the clutch shaft and input shaft can get sloppy and make noise.

When I get a new-to-me tractor I like to pull the belt pulley (or cover) and get a good look at the transmission gears and check the pilot bearing and input shaft play.

Pulling the PTO assembly is an easy way to get to inspect the final drive and with your hand you can rake out all kinds of trash that has accumulated at the bottom of the case. One time I did that on a 450 and came out with several bearing balls from a long ago failed bearing. Lucky they didn't get caught in anything! (And the 450 has cast in "ramps" to help prevent that sort of thing)

Ken, don't flush that rear end? I flushed an M tranny once. bad idea. you see, all those years and years and years of crud build up the perfect gaskets on the axles. Change fluid ok, but I would not recommend flushing with anything. Else you might end up with a leaking rear end. Just sayin. My axles, etc all started nice leaks after I flushed it with diesel fuel. won't do that again.

It almost looks like, for some odd reason and it could just be me, you have the magneto installed 180 out. It looks like you have #4 plug wire where #1 should be.

Well if I'm correct, the tab on the rotor should be pointing towards the #1 terminal on the cap when #1 Cylinder is ready to fire, (1-2 o clock position) correct? This is how I had it set up. The odd thing is when I would crank it through that stroke, after the mag impulse the rotor would be pointing towards the 7 o clock position. Is this normal?

I don't disagree with you on this. Maybe I'll reconsider and just drain and refill.

Lots of good advice here! Thanks! I've got a new pilot and throwout bearing so it shouldn't be those two items. I'll start with a fluid change and go from there. This is definitely going in my archives though!

The gauge does peg from about half throttle on, I know that both of my other tractors (of different makes) both do pretty much the same. I've got all the same gauges on all of them.

According to my manual, the tractor holds 8 quarts of oil. Air cleaner holds another quart.

Don't worry, both of these items are coming.

Number 1 is the front cylinder, you have it going to the back cylinder. Pause the video at 27:29. Tha tels me you put the mag on 180 out.

Should have clarified, I was referring to the pilot bearing inside the transmission. It goes inside of the input shaft and lines up the mainshaft.

I'll have to double check that. Thank you!

Take you a pencil and straight edge and scribe a line left to right across the center of the #1 tower on the cap to the distributor body.
The #1 tower is in the two o-clock position on the cap facing it from the rear.
Now take the cap off and observe the rotor as you hand crank the engine over.
You will need some help to crank the engine while you watch the rotor.
You should hear a click for each cylinder as the rotor turns clockwise.
As the first of the two marks on the front pulley pass the pointer you should hear a click and see the rotor pass over the pencil mark.
If you are late then you are most probably one half turn behind as you stab the distributor into the driving gear.
#1 cylinder is the front one closest to the radiator.
The remaining cylinders follow behind in their firing order.

added note:
Cylinders #1 and #4 both click on the double marks on the belt pulley.
#1 is in exhaust TDC when #4 fires.

I'll double check this in the morning - my guess is you all are right. I must be 180 out on the mag. I'll get it right before the week is out. Tomorrow I plan on draining the rear end, refilling, retorque the head, readjust the valves, and then figure out where I am at with the mag.

Thanks for all of the help!

As long as its firing on the right cylinder at the right time, I wouldn't worry about.