D2 starter pinion engagement

I am working on a 1954 CatD2. The starter pinion won’t stay in the engaged position. Pony will spin the diesel if lever is held in up position. I am wondering is this a sign of internal damage or an adjustment issue? If it is an adjustment issue, what steps are involved in making this adjustment?

Thanks for any information you can send my way

There is a latch system on the rear of the pony pinion drive, small hole in the top corner of bell housing has 2 bolts holding a round cover (just in front of operators left foot), in there is the adjustment screws that adjusts tension on the 2 latch hooks that lock the gear in position to drive, as it spins faster (from diesel running) it opens the latches to allow pinion drive to move out the way of fly wheel, the 2 adjuster screws have cotter/split pins thru the flat groove (yes adjust with flat end screw driver in same groove)make sure only half turn per screw then pin it again then try a test run, they are not nice to un-latch by hand, test run until it just kicks out when diesel fires up or it may take you pony for a ride it doesn't like with extra RPM up its back side. Best way I can put to words with out a manual copy to read from, i'm sure another member has better ability to copy paste the full blown destructions for the process.

typical horiz. pony pinion adjustment for the 3rd time--phhtt

Thank you Edb

Thanks to both of you. This is very helpful. The explanation about the adjustment was really clear. Pony is in the machine shop right now getting the valves ground. Once I get it back, I will be trying out these adjustments. Thanks again

If you look at the latches (item #3 in Eddie's picture), the notch needs to be pretty much at 90 degrees to the shoulder bolt to latch without being forced out of engagement by spring pressure and any slight movement between the two. The shoulder bolt should also be a flat true surface. If necessary, you can machine both so that they are true to the centreline of rotation. This will provide a solid basis for staying engaged during cranking and when the main engine starts to fire but not enough to start running by itself

Check the pulling lever lines up correctly to the end button to pull the pinion in to locked/latched position, my one was off set and caused one side of lever to wear away to not allow enough travel for pinion, a little welding to build up lever and gentle warmth to bent back to correct contact position

Thanks for that information. I will check center line of rotation.

Another question the starter pinion clutch has difficulty stopping the starter pinion from rotating. Any recommendations on repair or adjustment?

you may try using ATF (Auto Trans Fluid) in the pony clutch housing so there is less drag from the clutch plates and so ease the load for the clutch brake to handle to stop the spinning pinion shaft.

I do lower idle on the pony as much as possible before I try to engage pinion, it does help some but the teeth do get a good clean