Geoff Weeks

You jogged my memory about those. I had forgotten about that. Still, they shouldn't come into play with a tractor towing a trailer. Might be malfunctioning tho.

How old are your drums? (assuming drums not disk). Drum that have seen two sets of shoes are DONE! (One original, when the drum was new and one reline). They make look ok, but are hard and the lining never grips. I always changed drums every other lining change. Makes a huge difference. I assume the same hold true for disks but I have no experience with them. since the treadle valve supplies air to both truck and trailer, it would be less likely to effect only one of the two. Still the "clicking" should be looked into.

I hauled a KW like those to Maine Yankee for Barnhart's decommissioning. IIRC it was 11'8" wide. KW owned Dart for a brief time, so there are a lot of resemblances, between Dart, KW Pacific and even Hayes.

I thought that also

I think spring brake was the only requirement that was made "retro-active" meaning any tractor had to be fit with them even if they didn't have them at the time it was built. Most requirements allow for "grandfathering" so if the vehicle was built to the regulations at the time of mfg, it didn't have to conform to newer regulation. AFAIK Spring brakes are the only exception to that. Again, from what I remember reading, the Tru-stop driveshaft disk brake met the stopping distance requirement but not the self applying requirement of the spring brake law. I can't remember if the spring brake law only applied to tractors or if it included straight trucks over a set GVW. I know I have seen plenty of straight trucks with a mechanical driveshaft brake over the years, but more recent ones used a hyd over mechanical on the front of the diff for lighter trucks without air brakes.

CCC has no affiliation with Mack https://en.wikipedia.org/wiki/Crane_Carrier_Company

I could be wrong, but I believe all Astro/Titan cabs got the bigger front opening when GM started installing vendor engines in later production. I doubt that one was a "turbine" truck. GMC versions got a large one piece grill, I guess the Titan got the two piece?

You'll loose some road speed going down a tire size, 12r 22.5 is the equalivant of an 11 x20.

remind us again, are going for a pull or push clutch? I remember we went through that when we last talked about it. The hole for the push clutch below the shaft is different than the one for a pull clutch below the shaft, that much I do remember. Your trans is much newer than anything I am familiar with. I also remember from somewhere (could be wrong) that the tube was for pulling hard up a steep grade, the oil would go to the back and starve the bearings. Not something I think you'll encounter

funny, I brought it up on Meritor's site and it show current production?

https://www.ebay.com/itm/395726843402 Meritor shows it as an active part. Should be orderable though NAPA or any other parts house that deals with heavy truck brake parts. do you need the "hook" that goes in the shoe also? https://www.napaonline.com/en/p/MER1218C107

Does this look anything like it? 6 1/8" long by 3/4" diameter.

Since no one has of yet replied, I will say this: Just about any trans you choose can be fitted, I don't think there will be any that are a direct bolt in, change nothing fit. So it is up to you how much work you are willing to put in for the swap.

To clarify a bit. The old Stemco's had a wear ring. The newer unitized seal does not. So likely the wear ring has been discontinued because the original seal design was also. CR makes a "seal saver" ring when the original spindle area has been damaged. This is different (thinner) then the old Stemco "wedding band" and is a last resort for repairing damaged spindles. Get a modern unitized seal and be done with it.

Allows for bigger tire footprint for heavier loads. Many states require so much square inch of tire contact for a given load. To get 20K on a steer you need more than weight capacity on the tire in some jurisdiction, you need enough contact area as well. You can buy a tire that is not much wider than a common 11r 22.5 that can handle 10K/tire, but many places will not allow that much on such a narrow tire.