pony motor starting engine

That happens occassionally, get some penetrant lube in there and give it a good pry between the engagement lever and the pinion nose.....usually pops them free. Do not over stress the pinion engagement arm as they will bend.

Thanks I will try that.

I might be prying in the wrong place but no luck. The fan did begin to turn when I started cranking the pony but stoped while the pony cranked on up. pinion would not engage the flywheel. I cleaned out the clutch compartment with men spirits, but still no engagement, any other suggestions? Thanks Rusty

Your prying with bar or big screwdriver should be doing what the lever inside the flywheel housing would do. The pinion assembly is spring loaded.

Try pushing on the adjustment screw end of the latch dogs to see if they are free. They are geared together so you only have to push one side to check.

If the pinion assembly does move but won't latch in place that's another story. If that's the case either the latches (dogs) are worn and won't hold on to the stop or the sleeve attachment bolts have stripped and are not holding the sleeve in place. (fairly common problem)

If the diesel engine fan began to turn when the pony cranked up, the pinion must be latched in already. What does the pinion clutch feel like, any "snap" to it as you engage it?

Just to clarify, the pinion engage lever is the one on the flywheel housing (more toward the rear of the tractor) and the pinion clutch/brake lever is the one on the side of the pinion housing close to the injector pump/governor.

Hold the clutch lever hard forward with the pony idling slow to brake the pinion before shifting it into engagement with the main engine flywheel by lifting the other lever. Once it is latched in, it should stay engaged even though the lever will flip back down when you release it. If you want to release it, you have to punch one of the adjuster screws to pop the latches out.

Does the pinion grind when you attempt to engage it into the flywheel? Or does the lever lift up easy and seem to do nothing because the pinion is already latched in?

there is no grinding when engaging the pinion, the fan did start to turn slowly when I started the pony but stopped. The clutch has a snap overcenter when it is pushed and will slow the pony when I apply the brake. When looking in the clutch housing the two arms are latched, do I need to unlatch them. The last time I started the main eng with the pony I think I left the clutch engaged,since then it want engage the main eng except the other day it started turning the main eng but stoped when the pony cranked up. I have a maint manual but still scratching my head. Sorry Rusty But still working in it. Thanks for all your thoughts

My D4 is a 1952 mod you can start the main eng from the opp seat. I took the clutch/brake cover off and the inside was full of greese, cleaded all out and now I have no snap over center on clutch. My clutch has a spring loaded pin that fits into a series of holes on a small disk; There are three latches coming off the disk also. What is that? Can I adjust the clutch with the spring loaded pin? Still no engagement on the flywheel. Know anyone in my area that can work on one of these. Concord nc 704 788-6073

OK, whole new game from original described symptoms....
What you have now appears to be a situation where the pinion is latched and your trying to crank over the main along with the pony with either a loose or weak pony clutch adjustment.....can start to spin the main but then slips.

Normally your engaging the clutch with the main engine disconnected and using inertia to assist.

You need to do a couple of things...
Trip the latches so that you are set up for normal start.
Go through the adjustment procedure for the clutch until you get the snap over engagement, yes the pull pin is the adjustment lock. Better a little loose than to tight.

Those three levers are the clutch brake dogs. They fit into a cone shaped collar as a sort of brake drum.

Do you have manuals that describe the pony clutch adjustment procedure?