CA Project Pics

This is the "final" tach version (depending on how well it works installed).  I still need to make the "power" harness (both harnesses will be cut to length on site).  For this to work properly, the flywheel outer edge must be coated flat black and a single IR reflective strip will be applied.  The reflective surface must be completely smooth to prevent spurious impulses.  Depending on whether I can mount it close enough (< 2 inches) a plain white strip of tape or mylar will work.  In testing, silver mylar worked slightly better, giving increased range and a stronger more consistent return.  The width of the marker is to be determined.  I'll start with 1 inch to provide a reasonable duration and reduce likelihood of missed pulses.  

I also added a nice foam rubber gasket to the faceplate bezel and cleaned up the surround that was blocking some of the display pixels.

A view inside:
 

I was running out of time last trip so I decided to take the axle to the local (former) AGCO dealer for hand clutch repair.  I was a little concerned because he did the repair (including religning and new springs/ball bearings) without removing the brake drum section from the axle.  I bet that was difficult.  In any case, there was little chance of actually testing/gauging the correct tolerances that way.  After I got it back, I wanted to test it before I put everything back together.  I had to put just enough structure together to operate the tractor (i.e. rails, brakes, seat).  Initially it did not seem to be releasing.  One thing that was concerning is that on at least 2 occasions, in attempting to release the clutch, a large cracking noise was heard, like a spring/ball seat popping into (or out of) place.  This happened two times.  After a final clearance adjustment, then the clutch started operating "correctly".  It still has a slightly "off" feel to it, but my memories of using it are 50 years old.  It does seem to be working correctly though as far as I can tell.

Installed the welded and POR15 sealed final drive oil pan.  Added .75qt 80W90 gear oil...no leaks (yay).  I will give the other (left side) one the same treatment later (not leaking but I bet it has some water in it like this one did).  The rust pattern was weird...just needle sized pin holes with no rust surrounding the pin holes.  How is that possible??

A view of the rear end sand blasted and painted.  It has 3 coats of primer and 3 coats of color.   I bought a nice black seat cushion to cover up the crusty seat :)  If I had had another few hours this trip I might have installed the rest, but paint recommends waiting 7-10 days to let the paint cure.  Here I just installed what was necessary to test the hand clutch.  I also drained and put new gear oil in the tranny.  Overall, given that the hand clutch SEEMs to be working, I'm happy with my progress this trip.  A lot of progress in 6 days.  Even spent some time with my brother trying to get the M running :)

One problem I still have is that the governor seems to only bring the speed up to 1/4 throttle.  The throttle rod was "straightened" to just one bend just behind the starter and now gets me full range of the control mechanism minus 1 notch (was 4 notches short before...it starts bending the rod at the last notch now).  I can probably work the bending of the rod a little more and get the full range of the control correct.

I'm guessing that the governor spring is weak, but it doesn't look to be stretched.

The hydraulic hoses are split and frayed, I guess I'll try to replace those (hopefully I can find some swivel fittings that don't leak, I don't like the way they have to be twisted as-is).

I also cleaned up and removed some large dents in the belt pulley last fall and just installed it.

Showing where the seat was rusted through and welded and epoxy skim coated.  I originally didn't plan on fixing the hole, but decided to go ahead.  It came out nice and round-ish.  It was sand blasted further before painting but I didn't get a good post paint pic (but you can probably imagine painted rust pits well enough).

Those are some DEEP rust pits.

Installation clearance modifications: 

The tube clamp actually came with a slightly longer extension that I didn't remember.  If that one isn't long enough, I've made one that gives me much more flexibility.  I added a continuous groove for the pointed set screws to sit in to reduce the chance of accidentally pulling out.  There will be lock washers in addition to the jam nuts.  

The original clamp extensions only came with fixed set-screw positions.  If needed, I can similarly groove it given that it's unlikely that the fixed positions will give the correct angle for the display.

The sensor itself had to be cut to fit the opening at the bottom of the bell housing and the mounting ring just in front.  This required me to add an extension on the back side in order to provide enough clearance for the wiring harness.  The pipe nipple was grooved on the end to allow the PCB screw to mount correctly.  The nipple also decreased the clearance between the through bolt and the PCB so I ground a clearance in the middle of the through-bolt and covered it in shrink wrap tubing.  There should be enough clearance, this was just a precaution.

There will be a shortened nipple protruding upward into the bell housing hole to prevent rotation.  The exact rubber sealing arrangement is tbd.  I intended to use gloss paint, but my last can of gloss black stopped spraying properly before it ran out of paint (broken button receptacle in the can)...:(