D4 Pony Motor Starter Clutch Disassembly Question

I had one of those as a replacement part - I didn't like the cut of its jib so I ended up not using it. If you are going to replace it (I would), heat it right up and put a slice in it - then you can use a cold chisel to turn it. Then go back to the old c-spanner style nut

Got it off and prepared for re-assembly.
Thank you.

take a look at this video done by a fellow ACMOC guy. https://youtu.be/lKI3wTZU4AA this should give you a good idea he got some other videos on it too.

Thank you - I have watched all of his videos, and they were great.
While re-assembling my clutch - I am going to utilize his suggestion for beveling the bronze plates.
Thank you, again, for your input.

If they were supposed to be beveled, Cat would have made them that way.

There are definitely two schools of thought on bevelling those clutch discs, and back when I made the video I never thought it would turn out to be as controversial as it has. Some folks will tell you not to, others swear by it - I've received feedback both ways but the majority has been positive. I personally modify all my pinion drives that way and can absolutely say there has been zero problems in doing so, in fact the worst thing I've seen happen to the bronze discs is that they will gradually flatten back out and once again become flat, although in my experience it's taken over 10 years of operation to happen (as a low hour "hobby" machine, not a "daily driver" so to speak). Leaving the pinion clutch engaged for long periods of time will speed that process along and flatten them back out much sooner.

I fully understand the concern that the bronze material is prone to fretting or cracking under repeated movements, but in this application and with the limited amount of movement that occurs upon clutch application and release it has never happened in any of the units I operate. I do not believe there is enough movement going on to damage any discs before their malleability makes them lose the bevel and return to causing the viscous drag that sometimes makes it difficult to engage the pinion without grinding or bogging the pony motor. It's been well documented on this bb how this style pinion assembly has certain design deficiencies on the gear/sleeve end, where known failures are prone to happen with repeated pinion grinding or manually holding the pinion engaged if the latches aren't working/adjusted properly. Bevelling the clutch discs was one way I found to alleviate some of the abuse that this pinion design has to cope with, even if it is more of a temporary modification it's still worth trying in my opinion. I personally will take the tradeoff of modifying those bronze discs even in light of what theory states "could" happen to them, in an effort to avoid (or at least postpone) what we know "will" eventually fail on the pinion sleeve end. I stand behind this opinion, based on the real world results I've witnessed first hand on my own machines.

With all that said, I mean no disrespect to OM or anyone else, in fact OM is a wealth of knowledge and goes out of his way to help countless folks on this forum and others, and at a level of which I cannot match both in time and sheer information. It is not my intent to fan any flames or create friction on this public site, that is not my goal. But, on this topic, we just disagree and I'm OK to leave it at that.

In the end, it's up to each and every person whether or not they think the modification is a good thing to do or not, so take all information into account and make your decision based off of what you think is best. I wouldn't have put it in a video if it was something I wouldn't do to my own machine.

Out of respect for the original design (although some of it proven faulty), they are in fact a friction surface, based no doubt on flat surface contact area and are best used in that function. If they were meant to be spring washers a different design would have been utilized. All that aside they are the least of the problems of pony operation.

Hey Gang,

Both OldMagnet and Sasquatch are great benefit to our BB and Club. I remember rebuilding a pony pinion only to find Sasquatch's videos a year or two after. They are great videos and he does a great job on them. I found much drag on pinions, but was advised to use ATF. I am a firm believer in it now. I've always had it on my mind when the next pinion job to follow the video.

Anyway, both OldMagnet and Sasquatch do a great job. Thank you to both of you!!!
Glen