MUT: Murray Utility Tractor

Clutch pedal did its job today!

Was plowing the driveway and had to put down the clutch while looking backwards. I instantly felt the raised  edge and knew without having to look that I had my foot in the wrong spot. A quick slide of the foot and I had full contact and no slipping off a stupid clutch lever/bar at the wrong time.

Yep, that will work. Big and ugly or not, I’m keeping it! A little grinding and a bit of paint and it will look good enough for me!

She's looking really sharp. I like that red, wonder if there's anything a little bit lighter than that, could be a good candidate to repaint my Mutt. That pedal is nice too. I'd like to put a piece of something on the end of my clutch pedal so my foot doesn't slide off, but what you did is just perfect. I wish all tractor clutch pedals were that well made.

Well, I’m pretty tired of fighting with the shifter on the MUT.

For one thing, the shifter fan inside the transaxle is rusted down and the detentes are vague at best. 1st gear will stick solid to the point that I have to beat on the lever to get it to release at all. Gear engagement is vague at best and you’re never really sure what gear you are in until you let the clutch out, if you’re in gear at all that is. I’ve got a new shifter fan on order, but it’s been on order for several months now and I don't think it's going to arrive at all now. I may just re-weld the old one and file in some new detents. I can see where they should be, they're just mostly rotted away. I'm really just stalling on pulling the transaxle out and splitting the cases now. Not looking forward to doing all that again....

The other thing is it’s a major pita to reach down and shift that bastard when doing repetitive things like snow plowing. A bad back doesn't make it any easier either as that OEM shifter handle is pretty low in the center. The shifter location is probably OK if you're using it like a lawn mower where you put it in a forward gear and just go mow, but it totally sucks for use as a utility tractor.

So I started thinking about relocating the shifter somewhere higher and withing easy reach. So I started thinking and planning linkages, shifter handles, locks, etc....

Then I remembered the discharge chute lever left over from the snowblower attachment that I converted to electric control:



That's a pretty handy little lever, with shift knob and push/pull cables already in place.

I placed it on the RH side in an easy to use location to see how it looks/fits:





Being a “tractor part” it actually looks like it could belong there. A little more “finish work” and it could look right at home. It would also offer an easy solution as to where to incorporate the micro switches to activate the white reverse lights. Being a push/pull cable, it would be super easy to use it to shift the transaxle and offer lots of flexibility on how/where to mount it. Adjusting the exact travel of the shifter lever would be as easy as making the lever at the transaxle shorter or longer.

It will also free up space in the tractor for a few other components I would like to mount in the space currently occupied by that long shifter rod. IE: alternator, hyd pump, compressor, or even a "lockable" storage compartment if I wanted.

Time to seriously look at relocating that damned shifter!

Ideally, I’d like to convert the tractor to a hydraulic drive so I could have a forward/reverse speed pedal, but relocating the shifter will do for now.

Proof of concept:



Works!

Now to clean up that bracket and some of paint. Then make a small rod to connect the shift shaft to the new “actuator” and mount the remote shift lever where I want it.

Of course, I can’t just slap it on the side of the tractor. That just won’t do and my OCD would go ballistic! Lol! I’ll figure a way to make it look clean and intergrated. Pretty easy to do If you take your time and think it through before bending and burning metal.

After I get that done, I’ll have to pull the transaxle and rebuild the shift shaft detents. Then I can mark out the gear postions on the new shifter.

Success:



Shifts from reverse through to 5th slick as snot!

Here’s a quick snap of the lever I added to the transaxle shift bracket:



That interfaces the snowblower chute deflector actuator/pivot with the transaxle shifter. Since I built it from scratch, matching the rotation angles was just a simple matter of making sure the pivot points for the transaxle shift shaft and the actuator pivot were directly above each other (so they travel the same arc). Then it was just a matter of making the lever the right length to be able to select all the gears in the arc of travel afforded by the snow blower actuator.

It’s all assembled temporarily right now. The cotter pin in the mech will be replaced by a bolt and it will all get some black rust paint where needed.

Now it’s on to building a shift quadrant mount on the instrument pillar.

Coming together nicely.

Man I really like this concept a lot.  It's reminds me of my Dad's Ford 7210 with a loader.  It has 4 ranges you select very uncomfortably on the floor, but then it has 3 forward and 1 reverse gear for each range "on the tree" which is very comfortable for use with the bucket.

Well, try as I might, there was just no way to get the shifter mounted on the steering pedestal. At least not without it looking like total arse.

The fuel tank takes up too much space inside the pedestal and the bodywork is in the way if I mount it to the side. I’d have to chop up the back of the engine cowling and I’m not willing to do that. I want this to look as much as possible like something that could have come “factory” and not some hacked together home brew machine.

So I went with mounting it on the LH side by the seat:







Its certainly a more “lawn tractor-y” look and location, but it’s the best compromise location for ease of use and function. Would have been nice to have it in front where I can see it without turning my head away from direction of travel, but it is what it is.

I just welded a piece of angle to the ROPS support and bolted it on. Dropped the cables down through the floorboard, routed it forward and then looped back around to get to the shifter shaft. A nice gentle, wide loop is better for the cables than a tight one or something with sharp turns/bends. Looks pretty good there and the shifter handle is literally right where my hand falls when sitting. No reaching or bending to shift now. Later down the road, I’ll bend up a sheet metal cover for it (prob some of the same red paint) to make it neat and hide the cables and mechanism. Probably incorporate some shift postion numbering as well, perhaps a lighted number scale to aid with night/dark useage. I pretty much shift by feel, but a lighted number scale would look cool and offer a more “factory” look.

Now the center section of the chassis is nice and open:





Without that shifter rod sweeping across that space in a great big arc, I now have room to mount things like the small air compressor I’ve been wanting to put on the tractor. I’ll also likely use the space to make a small “hatch” to a storage compartment, where I will also likely mount the GMC “reel light” I’ve been wanting to install for a while now. And another bonus: I can clean up the wiring in that area a bit more since I no longer have to work around the shifter rod arc of movement.

The shift is now very postive, even with the buggered up shift shaft detents:



Fixing those rusted away detents will only make it even nicer to use.

Yep, very successful modification. Very happy with it. Well worth the effort.

PRETTY COOL AND INTERESTING SETUP!

Well, I decided to do something about that shift selector today.

Out comes the transaxle and split it open:



Out comes the shifter shaft, give it a good clean up and:



Yeesh, that is pretty gone!

But, I can still see where the center points were:



So I don't have to work out where the ball stops actually should be.

The ball is toast and the spring isn't in much better shape:





Gotta love rusty parts! Oddly enough, the only thing effected was the shift shaft and the ball. Must have been water getting in around the shift shaft seal.....

But with a couple bucks, that's easily handled:



So a little welding, grinding and filing gets me to here:



Yep, that should work!

While I'm in there, I pull the shift keys:



Toast:



You can see the wear on the shift points. No worries though. I knew they were going to be pretty ratched because of the messed up shifter detents and I've got replacements already waiting for just this occasion.


BUT THEN.........

UGG! GROSS!! Poor 820!!

Good Job on fixing the shifter arm!

I grab the new shift keys and compare them to the worn ones:






Well.......poop.

They are listed for the 820 transmissions, I guess just not for my model. I ran across several places when looking for the original 792123A keys and they listed the 792180A as a part supercession. They fit into the shaft slots, they are even the right length. But the shift collar is too wide to go into the slot on the keys. Without the shift collar, there's no way to shift the transmission! Grrr.....

I call my local parts guy. He says he can see the part number for the old keys, but they're 25 bucks a piece and I need 4 of them! Yeouch!

Then he says no one has stock on them. He can order them, but we're looking at at least two weeks, if he can still get them at all that is. His comment was that the Peerless/Tecumseh stuff is all getting kind of "obsolete-y".

Checking online shows them available, but all of it is "new old stock"; meaning it's left over parts that aren't being made anymore. On top of that, it's all stupidly overpriced and shipping on top of that!

So, with the tractor sitting on jackstands in the middle of the garage and the transaxle in pieces, I'm stuck. My choices are put in the old keys and use them until they're completely toast or head out to the lathe and make up a new shift collar where I make a couple thou shoulder on a new collar to fit the new keys. I could just shave the old shift collar, but I'm always very reluctant to modify original parts to where they can't be returned to original. Not because I think they're valuable, but because if the modification goes bad I've ruined an irreplaceable part ans then I can't even put it back together the way it was....

Neither solution makes me jump for joy. But the 792180A keys are still available, which is a leg up over the (I'm suspecting) obsolete/discontinued 792123 keys. The new keys do have a little different profile on the tip, but a little grinder work will fix that right up. You just have to be careful to match the profile and keep the steel cool. It's made of spring steel and if you get it too hot it looses it's tempering. You just grind a little, quench, grind, quench, grind, etc until you get to the profile you need.  

I do believe I will try them "as is" first though. If they work, they work. No need to grind them if I don't have too.

So, my course of action seems pretty obvious.; out to the lathe I go......


Sigh.

I have both of these variations of the 820s. The newer ones have slightly bigger shafts, i wanna say? I remember an old style shift fan would not swap into a new style case or fit over the old style shift ring. Think the shaft on which the fan goes was bigger too.

RichieRichOverdrive wrote:

I have both of these variations of the 820s. The newer ones have slightly bigger shafts, i wanna say? I remember an old style shift fan would not swap into  a new style case or fit over the old style shift ring. Think the shaft on which the fan goes was bigger too.

I’m certainly no expert on it, but I seem to recall there was a difference in the shaft end bearings as well. Newer ones have a locating “tab” and a different bearing or bearing material....meh, I could be wrong too. Doesn’t really matter to me at the moment, just gotta fix what’s in front of me!



Assuming the shift keys I have are indeed for an 820, I would say whatever model that they go to has smaller shafts. The land area on the keys where the collar rides are thicker on the new keys. Approx 2.7 mm in total for two opposing keys (1,35mm each). Assuming a similar sized shift collar, that would mean a smaller shaft or perhaps, deeper keyways. Either way, weaker shafts.

I’m having to “upsize” the ID of the collar I’m building in order to accommodate the extra thickness of the key lands. This would make the shifter slot on the original collar rediculously thin walled, approx 0.67 mm. But luckily, the shift “fork” is a super sloppy diameter fit in the collar so there’s about 2mm I can use to bring the wall thickness back to what it originally was on the original collar.

Unfortunately, this also means there will be a “space” in the collar between the keys since it would no longer ride on the shaft between the shift keys. I’m currently evaluating if that is going to matter or if I should make the inside of the collar more “spline” like in order to support the collar during shifts.

I’ll probably end up making the internal spline arrangement to support the collar. Having the keys bear that force just sounds like a recipe for binding and disaster. It just adds more time and one more PITA element to all this.

And just to add i ing to the cake; the orginal collar is tempered/hardened so I’m going to have to see if the steel I have will take a temper after I have the collar built.

Sheesh. Nothing like trying to keep old rigs running. It would honestly probably be easier to keep a model T on the road. At least you can still buy parts for them!

Lol!

Well, it only took a “measly” 4-5 hours on the lathe to turn out a new transmission shift collar:





It’s a precision part, which is part of the reason it took so long to build. The other reason is I only had a 3” dia chunk of steel and it takes a while to whittle that down to 1.5” dia when only taking 0.030” at a pass.

Tomorrow I need to cut the 4 reliefs into the ID to account for the added key height of the new style keys, clean up a few small details and then temper/harden it.

Where the reliefs will be cut, it will be down to a wall thickness of 1.5mm. Everywhere else it will be 3mm thickness. Thats plenty strong for what its going to be used for. The orginal part mics out at 2.23mm wall thickness, so I’m still in the ballpark of oem.

Heres a few more pics of the differences in the keys and collars.

Old collar, new key:





New collar, new key:



Hey look, a shift key tree:



Lol!

Nice macine work on the shift collar! Should work well.

Well, that went to s@%t pretty fast.

I was cutting the internal splines and my keyway cutter attachment bugger itself all up. No problem, I switch to files.

I'm creeping up on the dimension and the key's are still not sliding on the shafts. I end up going a little too big and the key stops end up partially sliding inside the collar. No problem. I give the keyway a little shot with the MIG so i can re-file it.

Except.....

The MIG blows a hole right in the middle of the shift fork keyway!

How the hell that happened I have no idea as the part that blew away wasn't even touched by the arc!

And since the shift collar needs to spin (now that it's locked to the shift keys) a hole in the land is just not going to work!

Grrrrrrrr.......

Screw it.

Back in goes the original shift keys and collar. They were working before, even with the frigged up shift shaft and the wear on the keys.

Totally pissed, I cruise ebay and find four 792123 shift keys. Costs me just shy of 70 bucks, but it's done.

Jeez, a guy just can't catch a break.....

Well.

Good news: I can actually find all 5 forward gears again as well as neutral and reverse.

Bad news; it shifts very hard and pretty much wont shift at all with the engine running.

Worse news: while working the shifter back and forth and getting it all to bed in and start to loosen up, the plastic cable holder on the shift handle snapped. So essentially, I have wasted the last couple days working on something I now have to chuck in the garbage.

Slightly better news: since I didn't modify any of the original parts, I can at least put the original shift rod back in and use the tractor. Even if it’s going to piss me off to no end. That shift handle was pretty sweet to use for the couple trips around the driveway I got before it snapped.

Back to the drawing board....the problem is the stupid sheet metal pressed bracket that bolts down over the 820’s shift shaft. It’s a sloppy fit and being pressed sheet, it comes loose and/or flexes too much when trying to shift the transaxle. That makes it hard to rotate the shaft and makes everything go in and out of alignment at random times. I think next time I’m going to make a flat lever right off the shaft instead of trying to use the....ahem...”high quality” Murray parts.

Something around 3/8 flat stock machined to size and precision fit to the machined hex on top of the shift shaft should be more than solid enough for that....bend that sucker you piece of Murray crap! Lol!

I’m going to draw on my aerospace background for the linkage. It’s going all push rods and bellcranks. No more messing around with cables and/or cheap brackets.

It pissed me off enough after wasting two days of my life that I’m getting serious this time. No more trying to make ride on lawn mower stuff do tractor work, it’s getting some serious beef!

Lol!

Ok, lets get on with shifter ver 2.0!

A quick rumage through my scrap pile turns up plenty of material to work with:



I may have to buy a few fasteners and such bits, but that’s more than enough to build the linkages and bellcranks.

The design is pretty much finalized in my head, now to get turning and burning steel!

Oooo, heim joints and bellcranks?? This is gonna be good......

for the shifter I would just swap in or build a fender shifter

SebastianAlbrecht wrote:

for the shifter I would just swap in or build a fender shifter

Parts are hard to come by here. Murray parts even harder.

The shifter is going to remain on the fender/ROPS where the cable shifter is now. In fact, I’m going to reuse the shifter handle and pivot from the cable system as thise parts are steel, alreay installed and will work in a rod shifted system.

AllisKidD21 wrote:

Oooo, heim joints and bellcranks?? This is gonna be good......

You would think so, but “Murphy” has that nasty habit of showing up for a visit at the worst times!

Hmmm....now that I think of it, “Murphy” is awful close to “Murray”.....

Lol!

Dragging my heels today. All I got built was the bellcrank pivot:

I never have any luck with cables, I stop trying a long time ago, LOL. Solid steel rods work great.

prancstaman wrote:

I never have any luck with cables, I stop trying a long time ago, LOL. Solid steel rods work great.

I string whole aircraft with flight control cables, soooo......

This was a plastic part failure. I should have known better.

Design change!

Teaser shot:



Can you figure it out?