Summer is here, and it's time for dirt work. My D6 has been sitting idle since winter. Getting it fired up today took a little work, but after some fiddling with the switch, the pony motor fired up, and the diesel too. Boy I love that sound. This machine is older than my Dad, but it's better built.

As I walked around the machine inspecting the engine, noting the work that needs doing on it, I noticed I was getting a lot of smoke. On closer inspection, I found that the copper tubing that runs to the oil pressure gauge had developed a leak, and was spraying a fine stream of oil on to the engine. So I shut her down to investigate further.

As it turns out, it looks like one of the studs/bolts(?) that hold the pony motor governor has snapped off, the governor has been loose, and rubbing on the copper tubing. I'm amazed how well the pony runs, given that the state of the governor. So I now I have two projects, replacing the copper tubbing, and taking the governor off, drilling out the broken stud/bolt (not sure which), and putting it all back together.

Of course in tearing it down I find that the thermocoupler for the temperature gauge is broken off, which leads to project number 3, and my question:

Is it possible to reconnect the thermocoupler to the gauge?
Is it possible to get a matching replacement gauge assembly?
Finally, is it possible to use an off-the-shelf temperature gauge, like I might find at an autoparts store?

My preference is towards something that fits the machine, but fundamentally, I bought the machine to use it, not show it, so I'm not that picky about historical accuracy.

If anybody has tips about projects #1 & 2, I'd love to hear them. Replacing the copper tubing looks straightforward. I'm a little more concerned about the getting the governor reinstalled correctly. On a related note, any recommendations on belts?

Thanks in advance for any help or advice.

No. (it's full of some kind of working fluid/gas which has leaked out.

YES, get it from CAT and tell them to not send you the adapter plate and 4 screws and lock washers that was required to replace the old original large gauge that probably never was on your tractor anyway unless it is a very old D6. (unless you just want to have all new screws etc) When you put in the part number for a temperature gauge for an old D6, apparently computer spits out the new gauge and the other bits even though most every tractor will have been modified a long time ago to accept the new size gauge.

Yes, you might have to find another adapter bushing to screw into the head, but the gauge probably has an assortment of them in the box. CAT gauge will have the colored bands which is good for when you're tired or just not really paying attention. Also good for when operator is not too swift of mind so to speak.

Probably simplest to get the belt from CAT, just make sure they get the right one if you only want one of them. One on the starter and one on the governor/water pump.

More questions:

So I've torn everything apart. Woo. woo!

In reviewing the service manual there is a discussion about how the governor should have oil in it. I've unscrewed one of the screws on the cover to check the oil level, and there doesn't seem to be anything in it.

So I'm thinking I should tear the thing apart, but I'm also concerned about destroying the gasket (Parts book 3B-2035), and not being able to get a replacement locally. Do I need the factory gasket? Could I use the gasket paste that I can get at the autoparts store?

Also, to get the belt off I had to remove the belt from the starter motor, which ended up meaning that I needed to remove the gear box that attaches to the starter motor. Spinning it, I get a lovely sound that reminds me of gravel in a metal can. It spins free, but I wonder for how long. I find the details in the parts book somewhat inscrutable. Should I be worried about this? Is it worth tearing this down and repacking or replacing the bearings? Thoughts?

Also, in terms of getting one from CAT, I've ordered manuals direct from CAT, but never parts. On old stuff like this, do I need to go direct, or do I work with my local CAT dealer?

It doesn't need much oil in the governor. Only ever takes enough to run out a cover screw hole that's at the 6 o-clock position. I have taken the back off and pulley cover of of several that were frozen up to free things up inside. Can't remember having any gasket problems. A little gasket cement wouldn't hurt. If you put much oil inside it will keep the pulley cover oily without a good seal.

To me the starter drive bearings are a pain to fool with. I would perhaps soak the whole thing in a can of light oil over night and hope for the best. It only turns for a short time (hopefully) each time you crank the pony. Drain it well and reinstall. The pulley should come off the shaft to install the belt if you can't force it between the pulley and the housing. That's where the correct belt comes in. It's not only the correct length and width, but also the correct thickness/design.

If your local dealer's parts dept isn't staffed by idiots, I would use them, I do know having a parts book helps speed things up over the phone to our nearest dealer. Also helps me figure out exactly what all I need the first time.

I don't know how you would buy parts 'direct' from CAT. Maybe I've been missing something?

Now I understand, you have ordered manuals from the CAT literature reprint site. I would say that IS best done direct, I have done one through the dealer and it was about 2X the price by the time it finally came.

Thanks for the advice. I should have waited a little bit before proceeding. For some deranged reason I decided to tear things apart. I'm quickly coming to the realization that I really need a hydraulic press.

There are two bearings that hold the spindle that connects the gear to the pulley. The one set of bears is truly, truly shot. So I'll be replacing that.

I'm hoping my local CAT dealer isn't staffed by idiots. I guess I'll find out tomorrow. I'm just amazed that I can still get parts for something that is 65 years old. Wish me luck!

So I went down to the local CAT dealer (Western States in Spokane.) Not only did they have almost every part I was after, but they had they in town. I had (almost) everything I needed by 6 pm the same day. Wow!

Interestingly, I did need the adapter plate. It appears that I still have the original gauge, or that the last time it was replaced, the "old style" was still available.

I suppose I should be taking pictures, but my hands have been too greasy to want to go near a camera.

So at this point along with a buddy, we've degreased most of the engine, and can actually see things. I've cleaned up and rebuilt the governor. I've also changed out the bearings in the housing with the starter motor gear and the pulley.

This morning I'll braze a new ferrule on to some copper tubing to rebuild the fuel line for the pony motor.

Maybe this afternoon I'll actually install the gauges that started off this whole adventure!