Geoff Weeks

My guess is a 14" Spicer, if it is what Joey Mack posted. Same clutch that Vlad was installing in the this post, and a VERY common clutch. A 15.5 has a flat flywheel and the cover goes over and surrounds the intermediate drive plate

I find they are very hard on PP and FLywheel surfaces, and tend to be "grabby". With any clutch, operator has a much bigger influence than material. I opted for higher plate load and organic, and the only time I had to address a clutch was a PP failure. All other times the clutch may have been replaced because the engine or transmission was out for another reason

2 spd rears came about in kind of a round a bout way. I was looking to change the ratio, and didn't fancy paying what yards wanted to drop-outs ready to go, so was looking for "cores" to build. I had the rear-rear core in the single axle Fleetstar parts truck, needed to be re-ratio'd and the side gears changed to slip in the DS402 housing and shafts in the truck. I found a front rear core for less money than a DS402 core (by far, less) and bought new ring and pinions and side gears and built them to DT402 spec's. I didn't need the 2 spds but found I liked them alot. Real nice climbing hills out west, from top (O/D) drop to direct, then downshift the rears and pull the hill in direct/ low range in the rear. It also gave me so many ratios at the low end, I would never have to "slip the clutch" under any load or condition. The truck came with 3.90's which may have worked out on paper to give the best MPG, but where and how I was hauling, 4.10 gave better mileage and didn't require shifting as much. It wasn't a big change on paper, but made a huge difference in practice.

Reducing parasitic loads wasn't my impetus, keeping moisture out of the air system was. I don't know how many drivers I've heard say "My truck is air tight, the pressure builds to 120 and sit there rock solid" while I hear there air drier blowing off every 20 sec! I never had anything coming out of the "wet tank" when things were as they should be. Often the 1st indication there was a problem would be a little water out of the wet tank. Most often it was the check valve on the top of the drier element that had come apart. My cabovers didn't idle until -25F, the Marmon with it much bigger sleeper needed more heat and I bought an air Espar I was going to add in addition to the coolant one already on the truck. Back in the 90's I built a APU, and while it was nice, it had its drawbacks. 1st was the noise, in a cabover I was directly above the APU mounted behind the engine. It needed maintenance and was heavy. For cold, the Espars do great, but that left either idling or motel when it is hot. As far as tires go, I never got into deep mud, but did get off road, including oil drilling sites, and my experience is: if rib tread will not get you through, lugs will not either, and your better off hanging some iron on the rear drives. 2 of my trucks were air start and one used a super-capacitor for cranking. Keeping moisture out of the air system, was good for air start, but where I really noticed it was in the trailer brakes system not freezing up in the cold, of course if you switch trailers a lot, you are at the mercy of the last person who pulled it.

Didn't go above 65 mph, and didn't idle! My truck with the 3406 had RTO14615 trans and came from the factory with 3.90's on 20" rubber, I re-ratio'd to 4.10/5.63 2 spds and gained between .75 and 1 MPG. It was Marmon's areo cab, with no exposed marker lights (were molded into the visor) or air horns on the roof, no external air filter on the side of the cb. I ran northern tier and almost never idled. If it was too hot, I tried to get a motel, most nights I slept with the windows open and fan blowing on me in the sleeper, in the cold I had an Espar coolant heater that kept me and the engine warm. I ran #2 when that was available, and "pump" fuel if blended fuel was all the truckstop had, I had a driver controlled fuel heater that I could turn on from the drivers seat and remained off unless needed. I checked and maintained tire pressure, ran "rib" or "highway" tread all around (no lug tires). I took care of air leaks so the compressor didn't cycle all the time. 10 min between cycles while rolling down the interstate was my minimum acceptable time. I had my cabover at one time would go 45 min between compressor cycles. I pulled flat-bed, and some loads are more areodynamic than others. re-bar and plate steel got the best MPG. Equipment like AG and truck bodies were the hardest on air flow.

Toe shouldn't be set before "loose parts" are corrected, Setting toe when parts can move about is pointless, trying to set while in "operational" (tires on the ground) but can still move due to loose bearings is no more accurate, as tires can shift. Take care of tie rods, king pin and wheel bearings before setting toe, KPA shouldn''t change unless the wedges under the spring seat are removed, spring eye pins must be dealt with if they are worn 1st.

What I'm saying is : electronic parts go "obsolete" quicker than mechanical parts do. You admit to having trouble sourcing parts for a 2016. To answer your question and to address the statement about 3406B's. I would run what I had, now down to the Marmon, with a 3406B. I don't know who said they only get 5 mpg? but I got 6.5 loaded 80K running west. Big Cam 4 I had got 6.3 to 5.5 depending on season (better in warm than cold) and Big Cam 3 was 6.0 to 5.3. It isn't just the engines I'm talking about, most mechanical parts for the electronic engines are readily available, but it is the whole truck that now runs on electronics. I had a co-worker scrap a (from my prospective) newer truck when the electronic dash went out and it would cost more to find a replacement in working condition then he felt the truck was worth. Even if no component itself has failed, electronics have massive amounts of wiring, and that can be a real problem. Wiring problems are, always have been, and continue to be a problem on vehicles, and they don't age well. While repairing the fault is generally cheap and easy, finding the location of the fault can be maddeningly hard and time consuming. On a mechanical truck this can be a nuisance, on an electronically controlled one it can shut you down on the highway. True story, guy had a truck that would run fine, and then die going down the road, it took a few tows and much time in the shop (where it worked just fine). Eventually it was traced to a wiring harness that had got pinched in the oil filter at some point and the insulation had been damaged, causing corrosion in the wiring harness itself. I don't know how many tows, and down time in the shop where they couldn't reproduce the problem. By comparison, my Marmon with the 3406B will start, run and pull down the road with no electricity what so ever, doesn't even need batteries. Only thing that would prevent you from doing so is the lack of turn signal and brake lights. Nothing wrong with any of the engines you mention, that is not the point I was making. Any of them are sound, but without there needed sensors, ecm and wiring they are dead in the water. Glider kits drive off the lot with all new wires, sensors and ECM. That is whole different deal than something 20 or 25 years old that has been exposed to de-icer for 25 seasons and all the things trucks go through in 25 year of working hard. If I had to choose one of those to run I would say the 12.7 Series 60 would be my go to engine, one of the later versions where the few bugs had been worked out but before 2004 MY The 3406B is a great mechanical engine and long lasting, but when fuel system repairs or "water in the basement' repairs are needed, they are much more expensive to repair than an 855 Cummins or an 8V92 Detroit. One more from "on the road files": I was west of Chadron,Ne and there was a truck stopped in the middle of US 20 unable to move, His foot pedal had failed, and was unable to move the truck. Cheap, easy repair in the shop, but an expensive tow and down time to get there. Nothing I could do to help him even get out of the travel lane and into some "lay by". Not disputing electronic deliver better fuel mileage, they do.

I did it with the wheels off the ground, blocks under the axle at the springs. That way the tires can be rotated without moving the truck. What is important is the difference in measurement between the scribe marks on the tire when the scribe marks are in front of the axle vs. behind the axle. easier to do with the weight off the tires.

Ok, take a look at what you wrote: your 2016 ate you alive, and parts were hard to find, but you want to jump backwards 20 years? Do you really expect parts for a 25-30 year old truck are going to be easier to find? Another thing that may or may not play into it is where you are working and what you are hauling. If you EVER want to go into Calif, that will require a newer truck. Anything made much after '92 or '93 is going to be electronic and have parts and sensors that changed year to year and are likely very hard to find. I was running 30-40 year old trucks at a time when they were still all mechanical. I also (if I do say so myself) am very good at finding and scrounging old, obsolete parts. The only part I haven't been up to my elbows in, with the the older trucks is a Cat 3406 injection pump. Cummins, yep, built those myself, Detroit 2 stroke are even simpler. I was a mechanic long before I was a truck owner, and had/have many of the tools and more important, the knowledge to tackle every thing that can go wrong with the trucks I had. I could build my work-a-rounds for parts that couldn't be found, but more important, I knew where to find, and could have the parts ordered and on the way, while still on the road. I'll be honest, I have never tried to keep an early electronic engine running 30 years on, I worked on them when they came out, parts were easy to come by, and I never gave it a thought. When I was buying my own, I stuck with mechanical engines. My Marmon was purchased BECAUSE it was the newest all mechanical engine I could get. I fear that 25-30 year old electronics may be more difficult to find SOME parts for than even older engine that is mechanical. It seams to me you would have the worse of both worlds, electronic parts that change about every year, and obsolete so parts aren't made either. Anything over 10 years old, it is almost mandatory to have parts manuals. Being able to do an internet search for a part number is so much more productive than saying I need X for a 1999 xxx model. I was fortunate, in that my years were still back when there were printed manuals. Dealers often purge there old stuff (which is likely where my manuals came from). Now everything is digital, and getting someone who has access to the data, to go look at it and tell you what you need, can be like pulling hairs.

If they are on the spokes and hold the wedges on, They should be 3/4" x 10 TPI

Did you check on the flywheel?

The company I was leased to back in the day had some M-11's that pulled some fairly heavy loads. As far as longevity doing that, I can not speak to. Trucking has been a race to the bottom for a long time now. To succeed and prosper you need to keep a strong two eyes on the bottom line and looking "cool" doesn't even enter into it. I sat with a co worker when his nice "Pete stand up sleeper"was repossessed and drove him into bankrupsy. Take it from me, it is not a pleasant thing to watch. I never gave a damn what I looked like pulling Butte (Homestake) Parley's or any other hard pull, and didn't give a hoot to how fast. Your posts seam to have a lot to do with "how it looks", too many have lost it all putting looks above function. I likely looked like "Fred Sanford" when my 6-71 powered Fleetstar was working a train de-rail and I had a 80' stretch trailer and damaged rail car on. It was summer and hot, and that 6-71 was screaming and dumping heat into the small cab. You know what? I got paid the same as the others with K900 and Large car Petes. I could take that old Fleetstar down the right of way and not worry about messing it up. The roof on the Fleetstar is about at the same height as the top of the steering wheel on my Marmon, I could take that old truck anywhere in Chicago and clear the low bridges. Function over form. If you have a solid "horse" under you, and bunch of solid dependable freight, then you can worry about "bling" and what your ride looks like. Back in the mid 90's I was pulling a boiler from greater Chicago to Ft Saskatchewan, AB. 315hp and a 9 spd grossing 118K. Yeah it was a long slow trip and I got razzed a bit climbing Butte, but the razzing was shut down in a hurry when I told them the pay/mile! That trip paid for a 13spd upgrade, and a few more like it paid for 400+hp. I WANT you to succeed, but to do so, you are going to need a shift in priorities.

One last thing, HP is not king! Everything I did was done with less than 440hp, and moved stuff with a 238 Detroit on the low end. When I called it quits a few years ago, I had a 425 cat, and two Cummins that one left the factory at 315 and was at that time putting out around 400, and another that left the factory at 400 and was putting out around 425. That made me among the lower end of the modern "fleet spec" of 2020, never bothered me a bit!

Made my living with 30-40 year old cabovers, a city tractor (Fleetstar) and a Marmon conventional. Times have changed as 67Rmodel has said. Camelback itself wouldn't concern me in the slightest, the 5 speed would for the reasons mentioned. When I started, trucks pulled hills on the interstate at 25-35 mpg, the fleet trucks closer to 25, the O/O's closer to 35. Those days are gone! Truck suspensions are NEVER going to ride like a car, no matter what someone claims. Ride comfort has a lot more to do with loading of the trailer that how the truck is sprung. Wheelbase also plays a roll, longer wheelbase the better it will ride. I had (still in my barn) a short wheelbase Hendrickson beam tractor (about the equivalent of a camelback), and properly loaded it was fine and didn't even have an airride seat! Put a ton of miles in a 4 spring cabover, and it too road just fine. Time to SLOW DOWN and weigh your choices carefully. As you now know, just keeping your insurance paid for and your paperwork up to date, as a carrier, saps most of your time and money. Jumping around, be it trucks or type of hauling or (for a company driver) employers, looking for the magic combo that put you in the clover, is only going to drain your bank account and break you. As far as 70+ MPH, I almost never went that fast, 65, 68 yeah, but even there speed drinks fuel (your 2nd big expense). People paid me to get their stuff there safely and in reasonable time, the difference between 65 and 75-80 isn't enough time to even talk about, the fuel will more than eat up any "bonus" you get from being there 1st. Cabovers went away in North America when there ceased being a need for short cabs (when overall length laws went away). A whole lot of the used cabovers were exported to other parts of the world where they are still in demand. I was approached a few times at truckstops by people wanting to buy and export. My advice as someone who "drove that road" is decide what type of hauling your LLC is going to concentrate on and look for a truck that meets that requirement well. Next best to to look for a truck that can do many things but is not so specialized. The key is to make a good decision in the 1st place and stick to it until/unless something changes radically in that sector of work. I my trucks were generallests, they weren't spec'd for one job but did most open deck work. That included heavy-haul up to 170k. While I could have been better off with a heavier spec'd truck in the heavy haul market, when there was a downturn, a heavy spec truck couldn't carry enough "general freight" to make money. Lastly, your loyalty should be to your LLC not the brand truck you drive. "back in the day" there were no truely terrible trucks, and the ones that were "not so good" didn't last. Today it can be argued that none are really good, and you make the best of what is available. Also insurance companies and some brokers, may balk at an older truck. I had to fight with one insurance company over having a '73 on the policy. None of my equipment was new enough to have to have E-logs, ABS, or even auto slacks, but I had little problem with DOT insp, other than the time they took on the side of the road. What problems I did have had nothing to do with the age of the equipment, things like a marker light that worked in the morning but quit before I got back home. No big deal. I ran this equipment until retirement after Covid (2020's).

1st, make sure the tires and rims are on with minimum run-out. Use a trammel bar and scribe to mark each tire at as near the center as possible at the highest point you can across the front or the tire, and take the measurement, or lock the trammel bar and the rotate to the back and check the difference. you can use anything to mark the tire, but the smaller the mark the more accuracy in the measurement. No difference for disk or spokes.