Geoff Weeks

Interested in the "starting capacitor". Is it like Maxwells ESM, where all the cranking current comes from the supercapacitor and the rest of the trucks electrical is separate? I ran the Maxwell on one truck for many years and loved it. Still have it as the guy who bought the truck didn't care or know what it was. That essentially makes the trucks batteries all deep cycle service, where no high current loads are placed on them. With the Maxwell, as long as the truck batteries were over 10 volt and could supply around 18 amps at that voltage, it would charge and the truck would crank. 10volts is likely way too low for these newer "electronic" engine systems, but would start an older diesel just fine with batteries that low. Maxwell came in 2 voltages 12 and 24, but either could be charged off a 12 volt system. Then Elon Musk bought the company an suddenly the Maxwell was not long offered for sale!

vernier adjustable cables. Check with a tow truck supply house. Most often a large black knob with a red button in the center. Pull for rough adjustment, twist for fine. Push the red button for quick release. https://www.amazon.com/Vernier-Adjustable-VCGTX10-Locking-Control/dp/B0CNRPV957?source=ps-sl-shoppingads-lpcontext&psc=1&gQT=1

I have had some really old (30 year?) Firestone bags. There are too many variables to know why they lasted. Like tires they are subject to UV and Ozone damage. Comfort/ride quality is determined by the design of the suspension not the air bag itself. The rolling lobe type that Hendrickson used is a good design, the "bell" shaped piston increases area as the the bag compresses. The Hendrickson splits the load between the Z spring and the bag. The bag does better are smaller high frequency bumps and the spring handles the large "swells" in the road. That is what made that design so popular. The last two question I have no knowledge to share.

Are you just talking about the "center section" (Gears) and not the whole axle? I don't know how Mack does it, but Eaton and Meritor, you 1st ID the housing by casting number/ visual to get the basic model. To then know what rating housing it was built for you look at the diameter and spline of the side gears, and may be the diameter and spline of the input. Only difference between a 34K and a 45K diff is the side gear/axle shaft diameter. The next size up starts a 46K and goes up. 34-45 use a smaller ring gear and fit a smaller housing. Axle housings are ID'd by the bearings, brake and tube thickness. So, if trying to ID just the gear-set look to the axle shaft diameter and spline in the side gear of the differential. I guess what I'm trying to say, is the housing determines the capacity not the gearset.

With at least part of the hyd running over relief, it would let you know soon enough. A lot of heat is produced when that happens for a long enough time. It would happen on some manlifts (a valve would stick) and it wouldn't take long before it melted the hyd tank!

Yes, if the rack is physically stuck, it would not turn off, and it would not be governed (run a way) so it is not the rack is stuck, but either the signal to the actuator is not right. The fact that it would "de-rate" says the actuator is responding to inputs, both to de rate and to shut down.

You are asking for data not normally in any "spec" sheet when these vehicle were produced! I have a Dart and the spec sheet for it, and most of what you are looking for is not contained on it! In heavy trucks there are many engine and other options that can vary from truck to truck that are of the same model. My Dart oil field could have 3-4 engines running gasoline, butane or diesel! You can look up the spec's for the engine from the engine producer, but "number of gears" and "what it is used for" can vary widely. Fuel consumption depends on how it is used, and is never listed by truck! dimensions vary by how the truck was spec'd. Within the same model tire size alone can effect width, height etc. Once delivered to the 1st user, the trucks are often modified for their needs, adding beds, winches etc. In short, you are asking for something that doesn't exist on paper, and if it did would apply to one truck of that model only, not all trucks of that model!

Plenty, but without being able to see and feel, not much help. twisted shaft, bent or damaged fork, interlock fail, shift tower problems, bearing failure, the list goes on. Your going to have to investigate more.

What hasn't changed a bit from the early days, is the number of axles to haul the weight and therefore the number of brakes to slow the load. 140K, 170K at 70MPH with the same brakes that were used when the speed was 1/2 that is not an improvement. More power will help get the load up the grade, but takes a good hand to get it back down the other side. I once pulled Butte, MT westbound and was one gear up from bottom, I could have used more power! only had a 315 HP at 1800 RPM gov limit, if that. Now we have big power, but still the same 7-8 axles and brakes under the same load. More power and the temptation to grab more gears and speed when pulling a grade instead of selecting a gear and riding it to the top, Much easier to do damage shifting under that kind of load on a grade, then taking more time and pulling to the top a bit slower.

Only thing that has changed, is the tolerance for slow moving large loads.

My DART oil field 150 has a 6-71 2 valve, they were rated at 200 hp! When they went to 4 valve they jumped to 238.

I showed up at a train de-rail, with a 6-71 (238 hp) Fleetstar, and was getting razzed, the old semi retired driver for the H-H company said "we used to move super loads with that power'. I used my Fleetstar because I knew I would have to go down an access road to retrieve the rail car. I took all the trailers down, turned them around and stretched them out for the other "large car's", on the understanding I would get the 1st load out! They ribbed me I could have the 1st load but would be last to be unloaded. The old gray hair said under his breath "don't you bet on it! You could here that 6-71 for miles, and I was the 1st to unload!

Pulling the same stuff we moved with 350-400hp! I moved the same stuff the oldtimers (at that time) moved with 200 hp!

Not up on the newer stuff, but I know Meritor (Rockwell) made some double reduction units. There are two different capacities you need to consider, one is the housing and brake capacity and the other is the torque/reduction needed to move that. The double reduction were built like a standard front of a tandem with a high input and a bull gear on the pinion, but differed in that the drive ratio wasn't 1:1 from the input to the bullgear on the pinon. housing and brakes were higher capacity, allowing to carry more weight.

The switch allows you to quickly test that both are working, You should see an RPM drop when firing on only one, often around 50 rpm. Start on both, flip to one, then the other, to check and then back to both.

It could be as simple as one module on the bus not "powering up".

Canbus problems and digital stuff in general is not my strong suit. However, there are people with video's on the net that can help. It would seam, and I can be wrong, that something is bring down the bus. I think the way to test is resistance across the high and low canbus lines. If it is off, then start un plugging (disconnecting) modules until the one that is causing the bus to go down is removed. Again, I am very weak on this subject, but with multiple comm errors it seams to point this way. What you don't want to do is start replacing modules trying to hit the right one, that can get very pricey and takes longer than finding the one that is causing the buss errors.

If you are removing the ground, but leaving the + connected, then you will see a voltage between the frame and the - side of the battery. Esp if measuring with a digital voltmeter. The question is: are you seeing a draw on the batteries when everything is shut off?

Paul, I'm embarrassed to admit I learned that one very late in life from someone else, but it does work, at least on the ones I tried it on.

Ken, I wouldn't say it was easy (esp in stainless steel) but is doable by someone who can flare and braze. If you have your old one to use as a pattern, you'll not need a drawing.

What I was looking for, was if there was battery voltage at the output stud. A test light is simple and easy to use for that. I wasn't concerned about regulator settings, as these type are fixed. either it charges to the set voltage or it doesn't. Another quick check you can do with the engine running is hold a small piece of steel close to the rear bearing, (A steel key ring will do) and if it is attracted to the alternator, you know the rotor field is energized. Once you know it is charging but have other problems a voltmeter is handy to have. A test light is quick and visual to see from a distance and almost impossible to mis-read. It will not tell the voltage, although if you "know your light" you can make an educated guess, but for work/doesn't work determinations it is a useful and rugged tool to have in your tool box. I wouldn't carry my Simpson meter with me in the truck, but I can diagnose most simple electrical faults with a testlight.

Here is my repair.

I don't know what the MH one looks like, but for my cabovers I made a new tube from 1/2" stainless tubing. length is the critical dimension to get right. On mine the bottom end was a compression fitting and the top end was a bell mouth to accept the "stopper" end of the dipstick, it was a separate piece from the tube itself, and was brazed on to the tube, I heated, removed from the old tube and brazed to the new. Stainless tube is hard to bend, you could use plain steel tube, which is easier to bend. Trick to bend tubeing: make the tube longer than it needs to be by an inch or more. flare both ends with a flaring tool, after installing(temporary) flare nuts. cap off one end and fill the tube full of "sugar sand" tapping several times to make sure it is well packed, then install the other cap. With the tube packed with sand, ends capped off, bends can be made without kinking it. If you try and make too tight a bend you can still split it, but most bends can be made easily. When bent to fit, cut to length blow and wash any sand residue out of the tube, and braze on the bellmouth!

I'm glad to help/

The type I think is supposed to have is what I have heard termed "vari-rate" spring pack, with a main pack and an aux pack above it, the top leaf on the main has the eye on one end to take the torque load. Very common single rear suspension. edit: may not be the top leaf, but one of the leaves in the main pack has the eye on one end.