Ol' Grump,

That's what I'm going to check next on my "baby" D2. I was suspicion of something like that. After I'm done reoganizing my work shop I'm going to check that out..oh, after I go surfing the waves are walling up here 8ft faces right now!!

I have a Cat 12 motor grader. the engaging lever on the pony motor is stuck, after I receently turned it over and it wouldn't start & I tried again & it was stuck. any suggestions?

You do understand that the pinion engagement lever is supposed to latch the pinion gear in mesh with the flywheel?
Once it is latched in, the only way to get it out without starting the main engine is to open the small cover on the clutch housing over the pinion and punch either latch with something so they release. Once the main engine starts, it spins the pony pinion fast enough to disengage the latches by centrifugal force even at low idle speed.

The lever on the front of the pinion assembly is the clutch and brake used to first brake the pinion and then to connect the pony motor to the pinion once you have it latched into the flywheel. This clutch is adjustable to maintain a light "snap over-center" so it will pull the load without slipping.

I'm a little fuzzy on graders but there should be a tractor equivalent plug on the bell housing that would give access to the release dogs and also the option to pry on the end of the sleeve assembly or the engagement lever to get it unstuck (fairly common problem)

thanks Guys, I'll try it in the AM

ccjersey, finally got my pony running but the pinion clutch is not operating as it did before the pony broke.Before the pony broke the mechanisim for engaging the pony to the big engine worked good but not great.During the course of the pony repair I discovered there was no oil in the pony clutch,my fault for not knowing it even took oil.I pulled the inspection cover on the clutch to find the big gear was froze up pretty good.I used a lot of light oil and then 30 weight and a lot of tapping the gear with a screwdriver and hammer but finaly got it loose.Everything looked and worked fine so I put oil in it after draining the dirty stuff.When I finally got the pony problem worked out I went to start the big engine and it was not at all like it was before.Now after locking to the flywheel I have to pull the clutch arm to the left with all I can muster to get it to engage the big engine.You stated that the clutch should snap in at halfway thru the pull,mine has never done that but always started and released easily before.My book is no help in this area,could you list the proper adjustment procedures for this clutch.Also now it wants to clash very hard to engage the flywheel,I put 30 weight back in ,should I drain it out and put in ATF? I appreciate any help. Don

Hi Team,
here is a scan from a D2 OMI, same set up as D4 and method.
Hope this helps.
Cheers,
Eddie B.

Don, in the "for what it's worth" department, I use either ATF or 10 wt oil mixed about half and half with diesel in the pony clutch on both my D2 and D4 summer and winter.

Yes, ATF.-glen

As far as the pony clutch brake goes, I have one that I can lean on hard and it will kill the pony before the clutch breaks loose. That is moving the clutch lever towards the rear of the tractor. What I do is pry against the lever sharply a couple of times and the clutch breaks loose and the gear stops turning. Then the pinion stays stopped easily and it slips into gear easily. This is just a "for what it is worth" in the "workaround" department.

Tom