Support is good. I may not be speaking your lanquage here, as a power generation millwright I may be taking some things for granted. Support means " supported IN ALIGNMENT" with the consequent shaft. Any wobble will destroy bearings in short order. This means that there must be room for shims under every mounting point. Every component must be adjustable up, down, and side to side. The tolerance should be .001 at each coupling. The clutch/engine is taken care of by the fits at the bell housing and the pilot bearing. The clutch/ input is all yours. You have to allow for the wobble at the engine end of the shaft and split that to get Zero, vertical and horizontal. The best coupling will be Keyed and shrunk to the shaft with 8 or more bolts holding it together. A flanged coupling does not depend on the shear strength of the bolts to transmit the power. It uses the bolts to develop enough friction between the flange faces to transmit the power. If all is aligned within .001 and properly torqued you should be golden. This takes time. If you are not a patient man this will make you one or drive you crazy.
I know you have the Cummins already. Have you thought about a Cat D17000 or D 19000? They are the right speed range, have a good sound, last almost forever. and are available. Could be easier in the long run. They may fit right up to your clutch assy.

I’m a mechanic by trade and not an expert in machining and otherwise.

With that said… I can tell you this. That Plymouth clutch, even at its best, is nowhere near the tolerances you are mentioning with its multiple shafts and bearing mounts. Plus it’s around 500lbs of spinning weight. I’m, also, sticking with my Cummins. I work on Cat D17000’s regularly and they are very rough old dinosaurs and underpowered for how huge they are. They do sound awesome, I’ll give you that:)

If you have a source for D17000’s let me know. We may need parts for the ones we have.

I have plan for the higher RPMs of the Cummins. Mainly by using the PTO to avoid vibration and slop from the original clutch. I also have a contingency in place that I can limit the maximum RPM on the Cummins if any ‘high RPM’ bad manners show up. I planned it out that I can limit the new engine to a similar RPM as original and still get the same torque and HP ratings of the stock engine…turbo chargers are wonderful! If I can run it faster with no ill effects, then that’s just a bonus. My performance and tolerances will be way better than when this Locomotive was new. These aren’t precision machines. Even the brackets that used to connect the engine to the transmission aren’t all that precise.

On a slightly different topic. I am using part of one of those brackets so that I can retain the factory clutch brake assembly.

I'm fully with tdmidget on the need for relatively high precision in alignment on the 'new' components, with the ability to shim them accurately. That there is slop in other components doesn't necessarily allow slop in new.

The potential issue I can see is overconstraint if the shaft takes a set when the clutch is engaged with slop at the ends of the driven shaft, but a properly pinned-near-the-centerline intermediate bearing. I don't think this is nearly the concern that an unsupported end would be.

You guys know a lot more about this than I do.

When it’s all put together, I’ll shim the engine mounts for an exact alignment between the PTO output shaft and the transmission input shaft. The PTO has its own bearings to support its output shaft. So that should eliminate slop and movement.

It’s going to be a few months before I buy the PTO. So it’ll be awhile before I set this all up.

Thanks for the discussion.

Here is the PTO clutch that I’ll be using.

Kappy,

I can't remember how the saying goes, it's either, "It takes 20 years to make a machinist out of a good mechanic" or, "It takes 20 years to make a mechanic out of a good machinist".

Either way, I applaud your effort and understanding of the world these things lived in and were operated in. Understanding "Theory of operation" is the most critical part of any repair. If you know your destination you'll always know what direction to head to get there.

I don't doubt, or disagree with, anything tdmidget or overmod has offered. I do think it's too easy to get caught up in "chasing thousandths".

I like your approach because you know you have to make it work first but have also taken into account how to correct and adjust any problems you may encounter.

I enjoy reading this discussion because it shows the two different approaches to doing something. Not right or wrong, just chocolate and vanilla, and both sides like ice cream.

Which flavor do you prefer ?

The concern I, and probably tdmidget, have is not that leaving it sloppy won't get the locomotive moving forward and backward. The same relates to the concern over the gears. I have no doubt they're relatively crude spur gears, comparable to the engaging quality of most geared steam locomotives, and would be prohibitivel expensive to reprofile with the correct crowning allowance, etc. to run smoothly (not that you could tell over the boom of the engine, as noted).

The concern is that if you're going to go to the expense of doing it carefully, you might as well take the time to do it right. There is a huge difference between the way a good modern steam locomotive, like T1 5550 or the 'rebuilt' UP locomotives, are restored than the way those locomotives were banged into earning over the road 'back in the day'. If you expect to restore something to best operating condition, that's different from kludging together something at minimum cost that ekes out a few years of waiting for something else to wear funny or break. What's the old adage about 'do it right or do it again'?

Especially in an age where money is harder and harder to come by, but the cost of buying or doing things is rapidly inflating... do you really have the desire to kludge? (Of course, if you're an 'engineering patina' fan, restoring the locomotive to as-operated condition might itself be part of historic preservation...)

Agreed.

I’ll consult the group here as I line things up. Trust me, no one wants it to be done right more than me. You should see the amount of time and $$’s I have invested so far. Plus much more to do…

The engine is in place now.

Will mount it enough to hook up the cooling system, fuel system, then test run the engine.

The front coupler pivot pin is broken just below the coupler. I was able to remove the top section and the coupler today. Getting the bottom part out will be a real chore. Not sure how I’m going to do that.

Will figure something out!

Busy, soggy Saturday. Made some progress though.

The input shaft housing is back from the machine shop.

The sleeve I provided was slightly too small so they made one the proper size. The new sleeve is just barely into the threaded holes. Looks like they ran a tap into the holes and it all looks great.

I’m still taking measurements and will machine the bearing retainer plate to fit. The spinning bearing wore it also.

Also bought a spare engine over the weekend. I’m going to convert my engine from a Low Flow cooling system to a High Flow. This new engine should have the parts in need.

Low flow? Well, I don't like the sound of that.

Looking forward to seeing it together.

Was an interesting experiment by Cummins. It worked to lower intake temps to reduce Oxides of Nitrogen emissions. It did the job but was overly complicated and was only used on BC4 engines.

I repaired the bearing retainer today and reassembled the housing.

We’ll see how strong I’m feeling tonight. I may install it in the transmission. It’s 140lbs assembled.

Turns out that I wasn’t feeling very strong that day.

In addition, the bolts that attach the input housing also mount what I’ll call the “bell housing shell” castings. The whole thing gets bolted and the input housing is sandwiched in between.

I loaded up the bell housing parts tonight. Will clean them up and add some paint.

The clutch release forks will go away, but I’m keeping the small lever for the input shaft/clutch brake. Will be nice to stop that input shaft from rotating before engaging a gear!

Just so I understand, the existing clutch will remain in place but without linkage to disengage it and the operable clutch will be the PTO, correct?