pony clutch D-4

I can't be sure right now I understand everything you are describing, but I will share some things I have recently seen with my pinion clutch on my D42T.

I pulled the front cover from my clutch. This is the one held on by the three bolts. The clutch would not lock in forward position. The clutch would brake and it would engage, but it had to be held in forward.

After fiddling with the adjustment I came to the conclusion that the adjustment was too tight. I loosened it and it does snap in now.

It may be that the travel on your adjustment is too tight and cannot travel forward. If that is the case, the starting engine should still start and turn freely without pulling the main.

The reason your pinion may not be locking is because the pinion and the main gears are not meshed???

I am not sure I fully understood the question(s) but maybe some pieces and parts from my description will help.

bernie

Sidehill,
If you took the little round cover (not the main clutch inspection cover) under the left floorboard off to free the pinion latches, you might want to spray whatever loose juice you normally use on the pinion and latches and as far forward as you can. The shaft can and does rust up a bit. .as long as the pony clutch is adjusted properly and working it will loosen up in time. The other thing that can happen is the pinion control shaft(s) might be rusted up a bit and possibly causing the "drag" you feel. With the pony not running and the little cover off, go ahead and engage the pinion and start working the pinion control while spraying what you can see and reach. See if that loosens it up. .then go ahead and disengage the latches again and you're ready to run.

thanks for the help..my pinion engages and disengages just fine..i did lube that up before I put the main clutch cover back on after I put the transmission cover. I guess I am having a hard time explaining my problem. The pony clutch is not moving forward and aft..shouldnt it be following the movement of the lever. When I take the small cover off the top of the pony clutch housing I see the throwout bearing moving with the lever, but the clutch just stays in one place, it doesnt seem to move. When I first started to work on this problem..you could turn over the pony motor by hand and the pinion was turning also,even with the clutch lever in the rearward/disengaged position. I got it to break free enough that now I can turn the pony motor over and the clutch/pinion doesnt turn with it. I messed with the adjustment of the clutch per the book...I might have got that wrong. Am I thinking wrong in that just like the main clutch you should see some movement of clutch mechanism when you engage and disengage. I will try readjusting the clutch.

On the pony crankshaft...I have alot of forward and aft movement..like 3/16 of inch, plus side play of a little less than an 1/8th inch. This pony hasnt run in ten years, but I see alot of old oil/dirt residue all over the pony, the right side rail, etc. I cannot believe with that much side play that the crankshaft oil seal can do its job...hopefully I will get a chance to find out if I can get the ole girl running..so far with all the curd I have found in the gas tank and sediment bowl, I will need to do a complete carb clean up to I believe..😞

Sidehill,
You won't see much movement in the clutch as it engages and disengages. When you adjust it, one hole plus or minus on the adjuster makes a large difference in how it engages and those threads are pretty fine. I set mine fairly loose. .just light enough it doesn't slip under power.

As far as the crankshaft movement on the pony. .that's waaaay to much. According to the Serviceman's Reference Book, .009-.015 with a maximum allowable .025 is what is called for crankshaft end movement. Main bearing clearance is .015 maximum and rod bearings maximum clearance is .005.

Ive got one D4 7U with a worn pony about as bad as yours. Rather than rebuilding it, I put an MT40 starter on the diesel per Old Magnet's site and am glad I did. Costwise, I think the starter and rest of the stuff probably was less than rebuilding the pony by a good margin ( all told, with hole saw, starter, switches, cables, wire, etc it came in at less than $500). At temps around 15F I hit the starter for a few seconds, then crack the throttle and give it a sniff of ether. .rumbles right to life. No more worrying about when the pony is gonna give it's last rattle and gasp. It works so well that come summer I'm gonna take the thing off and put the batteries in its place.

thanks ol grump...I got the mag working this morning..using the great advice off this forum..got the pony to run a few seconds at a time..with misting gas into top of carb..I thought about a starter conversion like you said...I also read how hard of a job it was for you..that one bolt next to the block seems to be almost impossible to drill and tap...still I a might do it..if like you said this pony is shot...I will get the carb cleaned up then run it for a while and see how much oil is blowing out...thanks..

Sidehill,
I created some of my own problems by buying a standard hole saw. .that was the biggest problem. Before I get going on the other D4, I"m going to buy a carbide tipped hole saw. .ought'a go right through the housing in a short time. To tap that hole next to the block I used a racheting tap handle. .just took a little time. I'll have the tracks and frames off the critter so most of the rest of the problems with the first one had won't exist.

Hello Bernie
My problem is the same as you.
Machine standing for a long time,clutch will not snap over.It won't disenguage main engine from pony when clutch lever moved.If I back off adjustment that should work?
Martyn

Martyn, My machine is a D4 2T-
If I understand what you are describing, the pinion will not disengage until the latches are release. This is done by either the main reaching the appropriate rpm for centrifugal force to spin them outward and release, or by manually releasing them.

I suggest, (because it worked form me trial and error), to remove the front cover of the pinion clutch housing by taking off the three cap screws. You will see exactly what is happening with the adjustment and how the plunger snaps into the ring. A little goes a long way.

Mine was too tight as it would brake the pinion so it could engage the starting engine while it was running, but would not snap over. I would need to hold it forward.

It sounds like two things are happening with yours. Look at O'l Grump's ideas and try to free the pinion first. Then pop the clutch housing open for the adjustment.

Can you start the pony with the pinion lever pulled up-meaning the pinion is engaged? If so it would appear that the clutch brake is working, and possibly stuck-If you cannot spin the pony without having to spin the main also, I suggest the clutch is locked in the engaged, (forward), position-If while the pony is running you cannot engage it by pulling up on the lever, I suggest the brake does not work.

I hope this helps...,

Hello Bernie.
This pony engine had not run for 12 years plus.
The fault is.I can start the pony,can't engage pinion unless the pony motor is stopped.After motoring and starting the diesel,the pinion trips out when the diesel starts.The clutch lever does not snap over when pushed forward.I guess the clutch is stuck.I was going to flush it through.Remove the inspection cover,adjust the clutch and try it again.Do you think that will fix it?
Martyn