Geoff Weeks

While I was looking, Barnhart's Pacific and my cabover hauling a line of Golhoffer trailers.

The one with the snowplows was on Hank's website, snapped by a tourist, the other is the three I ran, the small cabover in the fore ground was the back-up tractor. Marmon started life with 8 lug Motor wheels, and the big bunk had stud pilot originally On the snowplow pic, front drive axle has 10Rx20's on it.

I don't know where you guys are from, but I knew what he was after, the inside of the door, often a heavy fiber backed carpet or vinyl "Card".

Last I knew you could still order replacement trailer axles with spokes. I don't know about tractors axles. It is not hard to true spokes, but it does take the correct procedure. Any monkey with a 1" impact can over torque a disk wheel. When I had my tractor in for a front end alignment, the shop (a major truck tire shop) foreman commented I could teach their guys a thing or two about mounting Spokes. It is not hard to get them true, and I have noticed no wear problems or life difference between tires on disks and spokes I have one spoke wheel (tube type) that I am going to have to clean up and take a picture of. Some monkey with a 1" air impact tried to "torque them straight) and the rim is pulled into a 5 point star on the inner diameter and the lock ring is pulled out of the groove in between the spokes, never the less the assembly stayed intact and was run down the road. The amazing thing was the torque on that 3/4" stud! it held, how I don't know. I have had multiple cracked disk wheels, both hub and stud pilot, and multiple fractured wheel studs with disks. Since all of my stuff was used, I can never be sure of prior treatment. Repeated over torque of wheel studs has been a real problem, and you can't know what was done in the past. I changed my linehauls to spoke wheels and only the reserve tractor still had stud pilot disks. Somewhat like the argument of tubeless over tube type. People love to compare today's tires against the tube type's from the 70's or earlier. 70's tires were crap whether they were tube or tubeless. I am one of the few that was buying and running 10Rx20's. Not only did they last every bit as long as the tubeless 11Rx22.5's but capped as many times (I ran three treads off my tires, original, two caps, most would take a 3rd cap but the casing wouldn't last until the 3rd cap was worn, so I scrapped after two caps). Only thing bad about them is the tubes available are crap these days, if not used in a year, they crack and degrade sitting in their sealed bag on the shelf. I had started phasing them out toward the end because of the tube issue. A few years ago, I saw a brand new side dump trailer in transit to its 1st owner, It was a tri axle on 24" tube types on hub pilot wheels! That was an odd duck!

I never will understand the draw of disk wheels, minimum 10 (8 for Motor wheels, but they are mostly gone from the market) fasteners to get a wheel off 20 on inner stud pilot. 5 or 6 and I can have any rim off a spoke. Less torque on the nuts, so can easily change with hand tools. Lighter, don't crack, only draw back is inboard drums, but I know of a few shops that pull the wheels and hub together when doing brakes, regardless of inboard or outboard drums, their reason is they don't want a leaky seal to ruin a good brake job regardless if they changed the seal or not, they would be blamed, so might as well pull, inspect bearings and replace the seal on a brake change.

west Texas

Also county owned stuff can be weird, they spec it for a job and may gear it low to prevent clutch wear and speeding. Many times if you are employed by a government entity you don't have to have a CDL. I've seen ex county stuff with real weird spec 's 45 top speed. I saw a Loadstar tandem axle dump, 392 gasser and juice brakes on a 40K GVW. I doubt you could get that thing over 35 mph fully loaded, but you'd be crazy to want too with juice brakes. When the county or other agency spec's it, resale value is not even on the table.

As we go back to the 1st page on this, there still are questions asked but not answered. There are a total of 6 connections on the voltage regulator he took a picture of. As far as I know, the connection at the top has never been identified. The system is not a complex one, but if the O/P is not able to trace out where stuff is hooked to, where the wires go and what voltage they carry, I can not help from this end. If I were there, it would be a different story. As I have said, I have a very similar set up myself. It is not identical esp in the regulator. The field on these is isolated, you can ground one side and regulate the other to hold the voltage, or you can feed hot to one side and regulate the ground to hold voltage. Either way will work, and everything else is a secondary problem (like the relay connecting the output to the rest of the electrical system). IF voltage regulation is the problem, it is limited to the connections that make up the field circuit. If the O/P is unable to answer the questions or doesn't understand them, can't or will not trace wires, then the answer is obvious, replace with a single wire alternator and get on with your life. If you want to keep it period correct, you are going to have to do the things above that I mentioned. I can not from this end of a key board. These are simple systems, but they do require a bit of knowledge of electrical systems. I am not being harsh, but if you don't know, you either need someone on your end to teach or you need to move to something that is even more simple like a one wire system. Unlike a generator, where it needs to be polarized and have the current regulated, alternators are simple devices. We have no idea what he used to replace the rectifier, if it is 1/2 wave or full wave, of how it is connected, what its rating is for PIV or current. I was hoping a picture might indicate what he has, but so far no picture. Until there is more info, more cooperation I can't be of more help, and am going to leave this thread be. Good luck!

Can you get a picture of what you replaced it with?

That is one nasty looking air wiper. What does your compressor/air tanks look like?

Nothing wrong with the concept, it is implementation that has all the problems. I stayed with old school stuff until the end, it worked for me, but could also see the newer stuff getting better mileage and less fatigue for the driver. Because I did all my own work, the advantage of slightly better mileage was overruled by the cost of parts for the newer equipment. If I can overhaul an old engine for $1500 in parts, it is hard to justify the fuel cost for the newer stuff paying the difference. None of this addresses the reliability issue. Of all my trucks in 30 some odd years, only twice have any been "on the hook" and then only for a few miles, both times it was a fuel related issue. They were worked hard, and still managed to stay off the "hook".

If it were me, I'd be shopping for a core engine. Preferably a "running core". I have had one "repaired" head, and it failed. 6-71 that had a head crack. I know Cummins are fairly easy to find, I don't know about Mack's of that vintage. $1300-$1500 is what I paid. With the core engine, you get two heads, and plenty of other spare parts. I don't think you'll find a head for that.

John Hancock can be found on JOT, but I don't think that is his, he just took and posted the picture. Doubt it is going to be for sale at this point.

A good machine shop is a great tool to have your back pocket. Anything made by man can be re made by man, all it takes is money.

To be clear: You need BOTH positive and Negative diode sets, not one or the other. Which ever polarity the vehicle is, that diode set can be mounted to any metal, the other set has to be isolated. Although the old one was mounted to a metal bracket, there were insulators between the fins and the metal bracket. The old one didn't have either positive or negative connected electrically to the bracket that held it.

You need both positive and negative for full wave rectification. If it is being used on a positive ground vehicle the positive rectifier can be mounted to grounded metal, but the negative would have to be isolated from any grounded metal.

It will probably cost you the same or more to rig up some replacement rectifiers out of new diode blocks than it would to buy a used or re built modern one wire unit. Because yours is positive ground, you either need a case neutral (Like the Leece Neviile JB series) or a positive ground unit.

https://www.aspwholesale.com/index.php?route=product/product&path=71_262_274&product_id=6244 https://www.aspwholesale.com/index.php?route=product/product&path=71_262_274&product_id=6243 There are other choices and other vendors, I just pulled these off the net. this set is used in 130 amp Leece Neville alternators. Because of how the mount in the case in the alternator they were designed for, there is very little heat transfer to the case, so that makes them more ideal for a retro-fit where they will not be bolted to an aluminum case and have a lot of cooling are drawn over them. It is a good bet that your rectifier has failed, but as Paul says, before you pull the trigger on more than $100, test them.

Paul while I agree with you about lock ring wheel (I still use them, both on my antiques and up until I retired, on my linehaul stuff). I think the selenium rectifiers have plenty of drawback besides the toxic failure mode. They have a short lifespan compared to modern stuff, and for the most part any you find today are going to be at least 60 years old. At 12 volts you are running close to the limit for what one plate can safely handle in terms of PIV. As i mentioned before diode blocks out of a JB 2600 or JB 2800 would be fine. The spec's have already been taken care of for you as has the heat sink. The Leece Neville JB series today starts out at around 100 amps and goes well over 200. Initially they were made as low as 60 amps, but I haven't seen on of those in decades. I've included a photo of the Selenium rectifier and the JB blocks so you can get an idea of size. They would fit the bill, are nowhere near their limits (same blocks used on 24 volt and higher alternators) The black "kidney" shaped objects are the diode blocks.

Some more Wiki quotes: Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compound[3] with an exposure limit of 0.05 ppm over an 8-hour period.[4][5] Even at extremely low concentrations, this compound has a very irritating smell resembling that of decayed horseradish or 'leaking gas', but smells of rotten eggs at higher concentrations And: Exposure at high concentrations, even for less than a minute, causes the gas to attack the eyes and mucous membranes; this causes cold-like symptoms for at least a few days afterwards. I There are better rectifiers available. "Smells like rotten eggs in higher concentrations"

Pictures? Important to know WHY it happened, was the spring break a result of the collision or the cause?

It is up to you and the look you want, but here is my take (from an old flatbedder/heavy haul) cabinet style lockers are a pain for chain storage. Cheap but effective is to weld a heavy piece of flat stock along the top of the cab protector, with some added stiffners/ supports on the run, then hook the grab hooks from the chain on and interspace a binder in between. from the hook to the floor back up to the binder lower hook, back down and then back up to the flatstock. That way the chains don't get tangled and there is a binder with every chain. If the top of the cab protecter/bulkhead is 5' a 16' binder chain will not reach the floor and a 20' will barely. You can add a "chain tray" near the bottom if that is your preference.

If it come down to a failed rectifier, and it is looking that way, I would caution against looking for a replacement of the same type. I haven't checked mine, it may still be good, or it may not, but there is no way I am going to put it back in service. These selenium rectifiers were well known in small power generators of old (Onan and the like) for supplying field current. They are known to fail and are replaced when ever they are found, even if they haven't yet failed. With selenium, it is not if but when. Unlike silicon diodes which rarely fail in the life span of an alternator, selenium's are known to have a much shorter lifespan and heat tolerance. It was why the quickly disappeared when better diodes were invented. With silicon diodes an alternator is likely to not see a failure in the lifespan of the unit. Bushes,slip rings and bearings are now the much more common fail points. Brushes are cheap and easy to change, but when you get into slip rings and bearings it is often cheaper to replace than repair, unless there is a over riding reason to do so. When I overhaul an alternator, if the slip rings are shot, I generally don't bother replacing, I use it for parts. It didn't take me long to switch to brushless units for my stuff, as they can take higher duty cycles than brush units. Even pushing them to max output for hours at a stretch, the only time I had a diode failure was when something internally shorted the output. There are now air cooled alternators that exceed 300 amps, a domain that used to be exclusive to oil cooled units like the Delco DN-50. 100 amps is small by today's standards, and there are plenty of pre made diode blocks (diodes already pressed into a heat sink) that would make a fine replacement for the selenium unit, last longer and take less space and don't off gas toxic vapor when the fail.

Looking more and more like a failed rectifier, but TEST don't guess. READ THE ABOVE!!! HIGHLY TOXIC!!!

Selenium rectifiers had a shorter lifespan than desired. In the early stage of failure they produce a modest amount of sweet-smelling gas. Sometimes described as 'sickly-sweet'. At that point the rectification properties are almost totally gone, allowing reverse voltage to leak through the rectifier. During catastrophic failure they produced significant quantities of malodorous and highly toxic hydrogen selenide[8][9][10] that let the repair technician know what the problem was. By far the most common failure mode was a progressive increase in forward resistance, increasing forward voltage drop and reducing the rectifier's efficiency. During the 1960s they began to be superseded by silicon rectifiers, which exhibited lower forward voltage drop, lower cost, and higher reliability.[11] k Quote from Wiki, Also have heard and read it elsewhere. It is the prime reason, that I planned to replace mine with silicon diodes, which as you say will not smell or emit toxic fumes when they fail.