1955 d2 5u15771

This is definitely the right place to ask, although I will point out that folks on this forum tend towards wanting to get these old machines going whereas someone else might just see a pile of junk.
The general answer to whether you should continue with it is, depends on how keen you are to work on it. Mine was in worse shape than yours and I pretty much took it completely apart. But now it runs sweetly and of course I have a soft spot for it given the labor I put in. So a large part of it comes down to whether you just want a runner or whether you enjoy working on machines (I like both).

Post more photos detailing the clutch area and other points of concern so we can advise.

1. To free up the clutch, you can remove the clutch-to-transmission coupling (3/4" wrench/socket). It is in two halves and one half has keys/keyways in it. Once that's out, lift the whole clutch release mechanism/pressure plate/clutch plate out from the flywheel. The rear pressure plate retention and adjustment is the throwout spider that is threaded on to the front pressure plate, so spray some penetrating oil on it and back it all the way off, then separate the components. Knock all the pins out, buff/sand them, then reinstall with some copper antiseize. Ditto with the spider and threads. There are three small springs that keep the pressure plates separated when the clutch is disengaged. If the springs are broken, replace them. If the fibre plate is worn out/broken, pick up a new one from General Gear. Check that the transmission interlock is pushed back to be able to change gear. It is controlled by the clutch throwout spider movement.

2. Track wear looks pretty good actually, way better than the junk on my tractor. The link pin bosses don't seem to show any evidence of hitting the rollers that I can see. But the real way to check it is to measure the distance across five pins / four links - new is 24.48", 50% worn is 24.71", and 100% worn out is 25.07". The thing to remember though is that because this machine hasn't been used in a while, rust can be taking up some of the wear so it may appear the pins/bushes are less worn than they actually are. Best to measure after you've run it for a while to eliminate any false readings. Link height new is 3" - hardness depth on all these items is 1/4" total so 100% worn out height is 2.75 (2.69 actually but it's easy to think in terms of 1/4"). Roller diameter similarly is 7" new, 6.5" worn out (1/4" on the radius).

3. Wear limit on the pony crank radially is 0.015" (side to side), and maximum end clearance is 0.025" (front to back). But be advised that those are maximums with other variables controlled. If you have thinned out oil, or not enough oil, or if the rod clearance is high, you're increasing the risk. So measure accurately with a dial gauge to see what you have then report back. The good news is that it's pretty easy to replace bearings, and if the radial play is acceptable, but the axial isn't, this can be because the dowel pin that locates the flywheel end bearing can come loose. It's simple to get a new dowel pin from Cat, turn the bearing some, drill a new hole, and fit the new dowel pin. Also then enables you to slide the bearing up a bit to set the end clearance back to spec. Also note that excessive crank clearance can break your magneto shaft so it's good to take care of the clearance anyway. A note on oil - the pony only takes a quart, and there is no filtration, and if you forget to stop the pony by turning off the gas at the tank, you can dilute the oil and this can lead to seizure. So, since it's just a quart, replace it every year, or if you smell gas in the oil, or every "some" hours of operation, or every "some" # of starts.

Forgot to mention, on mine, the clutch chamber was also full of water, and some got into the rear main bearing of the diesel engine. This corroded the bearing just enough to stop the main engine from turning over. Once I got that cleaned up (ground the crank and fitted new bearings) the whole rest of the main engine was just fine.

more pics!!! looks like a good candidate to get going to me.

Negotiations have already been made but the guy has decided to hold onto the money in case the deal goes south. If I put everything back together and button it up he will give me my money back. Great thing about living in a small town and knowing people. They guy would never let it go for scrap price but to get him to even consider selling it was a blessing. He said he tried to preserve it the best that he could and knew if he let me have it I would at least take care of it and try to fix instead of scrapping it.

I think a lot of it will come back down to the bottom line of the price and availability of parts to get stuff running. I'm still of the mindset that they don't make stuff like they use to and I don't plan to use it for a living its more of the toy and hobby. Granted at the same time id hate to sink money into something just to find I can't get this one part to keep it running.

The unit had sucken into the ground so that I was unable to get under it to drain the water out of the clutch. After some persuasion with some blocks and jacks. its now up off the ground.
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The bottom rollers have some play in them up and down. How much movement is acceptable.
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It is one of the "newer" 5U's and has the removable top plate. However I am still unsure of how to get it removed without pulling the Pony. Anyone have any ideas on how much the Pony would weight fully dressed? Is it possible to get the clutch out without pulling the pony? This is a picture of after draining the water and getting it sprayed down decent with some WD40.

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The Transmission interlock won't move after being unhooked. I blame a lot of this on just age and the amout of time its just sat idle. however with the clutch being disengaged (lever forward) it should not effect the transmission?

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The Owner had the original manuals for it but seems like the one I am lacking is for the D311 engine. Does anyone have a copy they would be willing to send me electronically?



Many thanks for all the help so far.

manuals can be found on ebay--I would soak the clutch housing with diesel fuel,perhaps add a little atf also and let it sit and soak.
the master clutch has linkage and an interlock to the transmission shifter, mostly likely needs loose juice also. WD40 is not known for dissolving rust, PB blaster,Kroil oil,and 50/50 acetone/atf work much better. are the steering clutch levers releasing the steering clutches? or at least do you feel resistance when you pull them? D2's are known for the steering clutches to seize up, you can also try soaking them to free them up , there are drain plugs at the bottom of the compartments
rails ,sprockets and idlers don't seem very bad, The main clutch can be pulled without pulling the pony engine

What is the procedure or process to get the main clutch out. I think getting the top cover off is part I'm getting stuck on at this point. I can't get the top plate to lift high enough to clear the clutch disconnect bar that runs vertically thru the clutch housing. I am getting interference with the Pony crank even with the flywheel removed.


The steering clutches seem to be releasing or I at least feel some springy resistance as they are pulled back. The left brake does seem slighty seiezed but with some grease and gently movement over a few weeks with liberal applications of diesel ATF and acetone it is starting to show signs of a little movement.

What is the procedure or process to get the main clutch out. I think getting the top cover off is part I'm getting stuck on at this point. I can't get the top plate to lift high enough to clear the clutch disconnect bar that runs vertically thru the clutch housing. I am getting interference with the Pony crank even with the flywheel removed.


The steering clutches seem to be releasing or I at least feel some springy resistance as they are pulled back. The left brake does seem slighty seiezed but with some grease and gently movement over a few weeks with liberal applications of diesel ATF and acetone it is starting to show signs of a little movement.

[quote="Swaggy"]What is the procedure or process to get the main clutch out. I think getting the top cover off is part I'm getting stuck on at this point. I can't get the top plate to lift high enough to clear the clutch disconnect bar that runs vertically thru the clutch housing. I am getting interference with the Pony crank even with the flywheel removed.


The steering clutches seem to be releasing or I at least feel some springy resistance as they are pulled back. The left brake does seem slighty seiezed but with some grease and gently movement over a few weeks with liberal applications of diesel ATF and acetone it is starting to show signs of a little movement.[/quote]
lift the clutch shaft out with the cover. there is a bolt through the fork that moves the thrust brg coller. remove it first and be sure that the fork slides down the shaft freely.
Good luck putting that cover back on, mine was a real PITA and required 2 people.

Awesome advice advice on the clutch cover. I feel as if mine is seized in the bottom bore at least now I got some direction on how to tackle it.

So far I've found it easy in one way to work on but seems like everything is in the way to work on what is needed.


The comment on the nice looking seat cover and arm rest sure made it seem like it should just start up and go. At least it will have that going for it when it finally gets up and running or I run out of what is needed to make it go.

More help and comments is greatly appreciated. I'd like to see this thing run again as much as it seems everyone here does. 😊

You can get the clutch cover off without the clutch engagement shaft but you need to make sure it's right down. What I've done previously is to loosen up the yoke bolt like Riverina wrote, and then I knock the shaft down. It will/may knock the freeze plug out from underneath the shaft but that's ok, you can just tap it back in later. Probably good anyway to let some moisture out and let some oil flow down and through. Personally, I think this unit is a keeper