Geoff Weeks

I think the cab is widened out so you get enough sleeper birth width, no point having a 5' birth and a 5'11" driver.

And 13.2 "float voltage".

yes, or 2.2 volt per cell when fully charged.

That is a late/Euro spec. I have an '84 5 spd 16v turbo, and before someone say they didn't have the 16v in 84, yeah I know previous owner swapped it in. Scoots fast enough for me.

Crankcase scavenged 2 strokes (where you mix oil and gas) will run backwards for as long as you want with no damage. Spark is retarded (ATDC). In the 60's Saab made a 3 cyl 2 stroke, it would run backwards and could be driven, esp if you set the timing to close to TDC.

2 stroke Detroit's were known to start on their own, spontaneously. Rack goes full fuel when stationary and if they come in from the cold, warming air in the cyl can "bump" the crank, with multiple powerstrokes, it doesn't take much to bump one in to firing then it is "off to the races. Mostly V8's but I guess some 6's would also.

In most cases it will not run long, or have much power. For it to run, it must have fuel pressure to the injection pump or injectors.

Yes, it can happen, 2 stroke Detroits were the most common to do this, because of the multiple powerstrokes/rev. Cummins with a gear fuel pump are less likely Cats and others with inline pumps can. In all cases, the oil pump is a gear pump so the engine will see no lube, and is why Cummins don't maintain pressure in the fuel system to run for very long. Most can be starved of fuel and shut off. Detroits "flapper valve" will be useless as they are now on the pressure side of the blower.

Line set ticket shows it was originally a Ryder unit.

This sums up my take on it.

I've heard that for years with no citation of where it is on paper. Rust occurs between air around (or moisture in the ground if buried) and the item in question Galvanic protection works if you can provide a current between the two mediums. With a vehicle, the current would have to be between the air and the vehicle not its components. If it were the electrical polarity that was the cause, it would be simple to end rust by keeping the electrical system isolated from the vehicle chassie. This is done in ships (2 wires to everything) and they still rust! In ships two wires are use BECAUSE they rust. imagine trying to chase a bad connection between plates of steel over the length of the ship. Most mfg made the shift to negative ground when the switched from 6 volt to 12 volt. Some never were positive ground and some remained positive ground. GM for a company that was supposed to have strong armed, produced components in both polarities, the whole time. When transistors came around it is cheaper/easier to make them in the NPN format than the PNP, so having a negative chassie meant you could use the surrounding metal as a heat sink,cheaper than if it was positive. That said Delco (a GM company) produced positive ground alternators, with the positive diodes grounded to the case. Since the beginning Delco produced regulators optimized for each polarity, So Delco "didn't get the memo" from GM! It was semiconductors that really made the switch to negative ground ubiquitous. Once they started be common, positive grounds days were mostly over.

SQHD and SSHD both have 8 bolt 7" bolt circle axles SLHD has 12 bolt 5.25" bolt circle. SQHD is 38K SSHD is 46K SLHD is 34K SSHD the PDL goes in to the front case on the side of the case, SQHD and SQ100 along with SLHD the PDL attaches front the front of the input case. SQHD and SLHD have an idler gear "bump" on the side of the front case SQHP and SQ100 do not , front case is somewhat rounded off, SSHD has a more squared off case. I would stick to SQ100 or SSHD, I wouldn't buy a SLHD or SQHD. SSHD has a pinion bearing cover on the front case below the input/PowerDivider. http://www.canadawideparts.com/downloads/catalogs/meritor_outOfProductionSingleReductionAxles.pdf

Fairly dated but still mostly accurate. Not many "bulb rectifiers" in use any more. https://en.wikipedia.org/wiki/IUoU_battery_charging

White was, and "White Western Stars" sold here also were (No surprise). I know Mack did for a while also. I have no opinion on the subject, they both work equally well. In the old days you could flip-flop without changing much if anything. Once more "electronics" radios and the like, started showing up, then which polarity became more important. Paul and my disagreement has nothing to due with polarity, but with series and parallel circuits

Put a small motorcycle battery in series with a gp 31 and the current @24 volts will be limited to what the motorcycle battery can pass, Put them in parallel, and the current will be the sum of what the 31 and motorcycle battery can pass, but at 12 volts. Charging and discharging are the same. just which side is at a higher potential, determines whether current flow into or out of the battery. Just as in the above discharge experiment, the charge to the gp 31 will be limited to what the motorcycle battery can pass when in series and when in parallel the charge current will be the sum of the current to each battery. Ohm's law doesn't change. BTW, I could say the same about you and me.

No, not the case in charging either. Othewise you could just pull 12 volts off the middle of a 24 volt stack. In a series stack the weakest link controls the stack, charging or discharging. So loading one battery in a series string and trying to recharge through the whole string will fail, the unloaded battery will over charge and the loaded batter will undercharge. Any current to one in a series string must pass through all. That is not the case in a parallel, where a common voltage is applied to all, and internal resistance will determine the current though each. As I said, all battery systems in trucks have both series and parallel connections. When there is one dead cell in a battery, the battery is trash, you can't use the other cells. That is series in a nutshell. Parallel connections, all in the string "see" the same load or input. Any loss of one does not effect the rest, you could cut one battery out of a string and the rest will continue on. Li battery packs have to be very tightly controlled (as does the capacitor pack in a Maxwell starting system) to be sure all cells are brought up equally even though they are charged in series. Failure in series connection will show itself in that no power gets through, failure in a parallel connection will show reduced current, and may be missed by those who don't know what to look for. I understand battery systems, IUoU charging protocol and DC and AC circuits. You can believe what you like, but it doesn't change the facts. Neither is "good" or "bad" they just are, what they are. Internally batteries have both series and parallel connections, Each cell has multiple pairs of plates, all the + plates are in parallel in that cell and all the negative plates are also in parallel, the cells them selves are in series with rest of the cells in the battery to make a 6 (3 cells) or 12 (6 cell) volt battery.

The main reason for 4 six volts, was at that time there were no 12 volt batteries with enough cranking amps to start a big bore diesel. It had to do with plate construction techniques. You need between 1600 to over 2000 cranking amps @ 12 volt (1/2 that at 24 volt) to start a big diesel. It wasn't until new construction methods made thin plates (and therefor more plates in the same container) that allowed for the 900-1000 cranking amp 12 volt batteries. Gp 31 As to series vs parallel, it makes no difference, all batteries are made up of 2.2 volt cells in series. paralleling just makes the plate area bigger. Inside each cell in the single battery are multiple plates all in parallel to make more surface area. So a single battery is made up of cells with both series and parallel connections. anything in series is limited to its weakest link, so a bad cell or connection at one battery takes the whole string down. If the total area of cells are spread among differing cell containers (batteries) then one cell bad will take that series string out but another series path still remains. 4 twelve volts in parallel, have 4 sets of parallel connection for 12 volt start. 4 six volts for 24 volt start has 8 series connections, so any one of them is bad and you have no cranking. In the 12 volt parallel, and one bad connection reduces the cranking amps by 1/4. No one system is better than the other, all do a good job, the one with more connections need more maintenance to keep it working correctly. High amp connections are harder to maintain than lower amp connections. Which is why 24 cranking was used for many years, and is still used in many applications. It is why I like the Maxwell, it reduces the number of connections, and if a 24 volt unit is used, the current is low as well when compared to 12 volt cranking. It has only 4 high current connections 2 at the starter and 2 at the unit itself.

Here are mine.

Motorola, Prestolite and L/N are all the same company now. All produced "case neutral" alternators that could be used on either polarity. For a shop or service truck, it makes sense to carry one that can meet most of the needs, regardless of if it is the best or not. Sometimes when switching types (brush vs brushless) different pulleys are needed to increase the rotating parts speed. For example my cabovers could be had with either the L/N or the Delco 25SI but the pulley called for was a different size for each. The L/N had a bigger (slower) pulley than the Delco. Stocking for my needs, I buy what I think best suits those needs. To be honest, I haven't run across a 12 volt positive ground truck in donkeys years. Esp with LED and ABS controllers on the trailers now, negative ground has become the norm. Better LED and I suspect all ABS equipped trailers will have a full wave bridge rectifier in them to isolate the electronics from the vehicle chassie, so they can be towed by an older truck. The need for + ground stuff has mostly gone from the vehicle market. All my 6 volt stuff is positive ground, but that is it. I have an early 100 amp 6 volt L/N I am restoring thanks to member of another board. They were made in the 40's. Edit: We don't know if his truck is 12 or 24 volt, not that it matter much as all mfg make 24 volt stuff as well, often only the field and regulator are different.

Had F and L in red on my IHC's and thought they looked good.

I'm partial to the 25SI myself, but it is a big lump for its output rating (75-85 amp)

It is an SAE J180 mount, and should take any alternator made for that. I've had many that just quit, enough of them that I don't use the JB anymore. Used to be able to get an external regulator adaptor for them, last time I saw one it was expensive, but you could make one easy enough. Rectifiers are rarely the problem, newer one are ac triggered regulator and don't use a trio. If I were buying new it would be brushless, Denso, Delco, Electrodyne and others all make brushless. Electrodyne is a brushless clone of the JB L/N, but haven't seen one in donkeys years.

Also, they don't ground through the case, both + and - need cables on the studs. That way the alternator can be used positive or negative ground with no changed to the alternator itself.

Regulator on the top is a common fault, along with the brushes. If you have the regulator off, might as well put brushes in while it is out. Almost all I have done, only need a regulator, the rest of the parts don't often give much trouble.

ISSPRO made the speedo I put in the Marmon, as well as the 270 deg sweep ammeters I put in the trucks. Also made the air suspension gauge in my IHC. Used to be in Portland Or.