Geoff Weeks

I'd have to look in the Bendix book, but compressor duty cycle and that of the drier are low, like 25% max. Any air leak increases the on time. You can increase the compressor displacement or decrease the air usage. On truck compressors often it is only the head that is water cooled, the block is left to air cooling, getting to much heat can pass oil.

My guess on why air driers never were big in other parts of the world has to do with the compressor systems used outside North America. Our compressors have an unloading valve in the compressor it self, while European designs opted for a discharge line unloader. Without a signal line from the air governor, our air driers will not work. Air driers have only been around since the 70's or so. Now they are made in configurations that will work with the North American and European style of governor. Leaving the spit valve open a crack is just like having an air leak, it cause the compressor to cycle more and therefor puts more moisture in the system. I only got dry air out of a wet tank if the drier was working properly. Even with the added use of air start and air wipers, If I saw moisture, I could find a fault in the drier. At one point, my 4 axle tractor, hooked to a tandem axle trailer, all air ride, with the above air start and wipers, would go 45 min between purge cycles rolling down the highway! That was a tight system, less than 15 minutes between purge and you have some real work to do. I hear trucks going down the road with multiple purge events in one minute! I had AD-2, 4's and 9's as well as tried some Rockwell units. I settled on the AD-4 as the best of the bunch, and bought "cores" from wrecking yards to a few on the shelf. Often the flapper check on the top of the drier element is the problem, it fails and allows the purge volume to escape all at once. AD 2 and most 4's don't have a turbo cut-off in them so either needs an external one or N-A the compressor. The colder the air, the less moisture it contains. so if you see moisture in your wet tank in summer, you know the drier is letting you down. Might not see it in winter, unless the drier failed totally. I had some AD-9's that did that, the drier element is threaded into the aluminum base and the threads wear out and the element becomes loose inside and does nothing.

Not me! I used to be conceited but then I learned I was just great!😄 How boring life would be if one didn't screw up in a real spectacular way often enough to keep us (me) humble. I've done some real bone-head things, and lived to laugh at them, but vow not to repeat!

Think about it. Often a hand on the stick when the clutch is pressed, whole truck torques from the dumped clutch and the guy is still "hanging onto" the stick. Gears under load and a pull on the stick, something is going to happen. Just popping a clutch with no human in the drivers seat, I would agree with you, but don't factor out the human!

It has a connection for a line, what you connect it to is up to you, however I don't see how the little bit is uses would effect a modern diesel, but stand to be corrected. Air tool oil isn't a whole lot different then diesel, and for lube quality it has to be good enough or the injectors would seize in the engine. The lube injector is a simple device, with a spring and a small chamber that is filled from the lube source, when the main line for the start motor gets air, high pressure is generated (large area over small) and the lube gets sprayed in. I can't see why a T in the return line would cause any problem with a modern engine, but am open to an explanation as to why I am wrong. The reason diesel is used, is because if a remote lube tank was, chances are very good it wouldn't get filled. Lube tanks are used on Natural gas engines with air start With diesel available it is a no brainer to use that..

The problem with diagnosing on the internet, is you are relying on someone else eyes and judgement. He said "as far as he knows" that the clutch is working. I take him at his word. It would be easy to tell if the clutch is working, as the truck would move if the engine was running and wouldn't if the pedal is pushed. SO I doubt it is a clutch problem barring more info pointing that way.

Don't be too sure that it was you, there were three of us, so his "complement" is somewhat murky!

Yes, you would need Stud pilot wheels. Finding 20" aluminum wheels today that are good enough to run, would be a challenge. Steel would be no problem, I have several. If you want Aluminum than 22.5 is likely your best bet, although any non-hub pilot wheels are getting harder to get new. but there should be a good supply of used.

One final comment about noise. Without a muffler, all air motors are LOUD, and make a noise that is like fingernails on a blackboard to many. An air starter on a road vehicle should have an air muffler on it. Muffled it still sounds different but no where near as loud. I parked my tractor between my garage and my neighbors house, not a lot of space, but they said it never woke or bothered them when I left early. Yes, I asked them, good neighbor are kept good with a little good manors. Those that think startling people with loud noises, are a bane to the trucking industry, Jakeing through town at night while people are sleeping, With straight pipes of course and running un muffled air starters to make others "jump" are making all truckers look bad. If you have an engine in a marine engine room or a generator in an enclosure, then you don't need a muffler, but a truck does. They are a small "can" filled with metal turnings, that quiets the "bark" while having minimal back-pressure on the motor. With a muffler they still sound like an air start, so if that trips your trigger, yes everyone will still know you are "different' than the crowd, without being an A-hole. When "over the pits" at a DOT inspection, I always give them a "heads up" of what is coming when they ask me to start the truck. Many will have never seen one with an air starter.

One "drawback" so to speak, is that as the motors wear, they leak more air internally, but still do the job, just using more air to get it done. So how long they will crank on a tank of air goes down, but the casual observer or inattentive operator will not notice any problem, until it uses so much air that it is hard to supply enough to get the job done. When I got mine in the 90's they were off Roadway trucks, so saw a lot of starts, but neither needed a "kit" which at the time was around $50 but I know they are more today. One used a little more air than the other, and likely would have benefited from a kit, but neither used enough to be a problem. Both had the diesel injector at the motor to lube them of start. Compare this to an electric, which if worn, will have great trouble cranking. The trend today in air start is away from vane motors and toward turbine starters, almost no wear with a turbine, but require cleaner air (will not tolerate any debris). They have come up with low pressure turbine starters that can run on pressures as low or lower than vane motors. Mine (vane) would crank well below 50 psi but needed close to 70 for it to start cranking (move the pinion into the flywheel), but once it starts to crank, it will continue with much lower pressure. Another common mis conception is they aren't good at altitude. While it is true that the absolute pressure goes down, the higher you go up, so does the compression pressure in the engine. Also a tank that is charged at lower altitude holds that air at higher, so tank pressure is the same, but cranking resistance goes down. I've seen tank pressure rise to near 140 psi when I started the day in Denver and went up from there. Both altitude and temp (air tank warmed as the day went on) made the tank pressure higher. Also air starters tend to turn the engine over at a faster speed than the same engine cranked by batteries, and with diesels, cranking speed is 9/10ths of the job.

OK, as someone who ran them for over 20 years. Here are my comments to a few of the thing written above: The way many work, the stater motor uses a "pre engaged" pinion into the ring gear. a small (-4or 6 I forget) line from the air start tank goes to either an electric solenoid or air start push button on the dash. They are tighter buttons than normal air buttons and can be used with Natural Gas (so no leakage) in place of air for starting compressor station engines. The control air, then moves the pinion forward and opens another port that supplys the big relay valve back at the tank to open. Other (older) unit use inertia type starter pinions. Most are pre engaged today Manual valves have gone out because of the reasons stated, the move from inertia to pre engaged and the prone to leak problem. When running any of the lines that will see tank pressure, use a one piece line with no unions and the minimum number of fittings, The main relay and check valve should be directly mounted to the tank if possible. Mine will crank for between 30-45 sec on a full tank, but as other have mentioned an engine can start faster than you can remove your palm from the button, meaning you have many starts on one tank of air. Cold weather: They are much better than batteries in cold weather, they don't lose power as the temp drops. Hp required to crank a diesel increase as it gets cold, precisely as batteries lose their ability. I think the coldest I have cranked cold engine with my air start was -25 (F) I have cranked a warm engine even colder. Air start does require a dry air system, if the air is dry, the valves don't freeze. Air contracts as it cools, expands as it warms. I have seen a 5-10 psi variation in my start tank, just from air temp. I never used alcohol in my air system but did use a good air drier (AD-4's) and made sure they were serviced. Not only did it keep the start system working in the cold, it kept the brakes working in the cold. The inlet check valve is important. it is what separates the trucks main air system from the start system. It has to have a low "crack" pressure in the forward direction and good seal in the reverse direction. I use Ingersoll- Rand valve made for air start service. Only time I had trouble with them, was if the truck (valve) sat un used for a few years, they seamed to "take a set" on the rubber disk. One thing I always did when I shut down the truck. I would "fan" the brakes to drop the truck pressure lower that the pressure in the air start tank. This allowed the differential of pressure across the check valve to be 10-15 psi higher in the tank than the truck system and kept a good seal on the check valve. When the pressure is about the same on both side of the check, there is very little (spring) pressure keeping it closed. You can easily blow through it with you breath. It is a trade off, if you make the crack pressure higher (more force needed to open) the tank will not charge as high as the truck system can provide, but with the very little spring pressure holding if both systems are at the same pressure, the truck systems leaks slowly the check can also leak slowly. By allowing the start tank pressure to be higher than the truck system at rest, the spring AND tank pressure act on the seal disk and keep it leak free. The I-R starters are rated at 33 hp @ 150 psi and at around 120 PSI they are around 23-24 hp.

In the 25 years or so, I have to replace one tank check, one tank and one relay. Total cost was less than 2 truck starting batteries. My used units came off Roadway trucks, and had I don't know how many starts on them. I have been stranded by electric starters many times. As long as I had air, it never failed. Never had to "go into" the motors themselves, never a need to. Lubed with diesel from the return line from the injector/pump. Gets a shot everything the motor is used.

ASC out of Texas has parts for most of them. I've changed two trucks from electric to air, and it is as simple of un-bolting one form and bolting in the correct replacement. Why anyone would change from air to electric, is beyond me, but it is your truck. You would be going from 23 hp motor to 8-10 hp. Air systems can be self-lubing, and can outlast the truck. The air side is simple, wet tank to inlet check, tank and air (solenoid)Relay. I have mine hold enough air over 5 weeks of inoperation, to start, and the truck has 10 tires that can boost if the tank is low (but not empty). To go to electric, you need to add the parts (starter button, relay cabling and enough batteries). your choice.

If this is the case, it may feel like it is neutral, but you'll not be able to hit all the gates, nor move the stick unto another gear (if the interlock is working like it should). If you can move it into gear, then you have bigger problems, than just a shifter interlocked.

I does look that way, I can't be sure just from a picture. There are commercial #1-#2 adapters made and sold. With a #1 you should be able to put whatever trans you could find a clutch to match the flywheel. SAE spec determines the clutch depth. Flywheel and clutch would be the limiting factor

Credit goes to you DCW, it was from the link you posted, 2nd page.

In the Yoos brothers post you can see the bell and trans clearly

some of those pic's look like it had a #1 and they used a #1-#2 adapter!

My guess would be they used an SAE#2 bell on the engine. Chry used the 413 in their medium trucks until the bowed out of the market in the 70's. Still make medium trucks in South America last I knew. Since they would likely already have a #2 bell for their trucks and/or industrial market for the 413.

I ran Isspro's 270 deg sweep remote shunt ammeters and loved them. I have since seen they have changed them so can't say if the new ones are as good. I could read a draw as low as 1.5 amps and they read up to 100 amps draw or charge. I'm sure someone else must still make something similar. Isspro's new gauge is more expensive and uses a sender "donut" that the cable has to pass through. I found automotive 90 deg sweep voltmeters to be inaccurate and hard to tell what is really going on. I had both gauges on all my trucks, but just because they came with voltmeters. I could see a bad cell in the battery or a bad diode just by watching the ammeter. With both it was like having a VAT connected up at all times. your gauge looks like the insulator around the mount cross bar failed

The above corrects some of the wrong info I may have inadvertently posted. Like they all have 18" ring gears not 17" and they where used in heavier axles than I listed. Sorry for the mis info, but the heavier axles are not my area so much. Been all through the lighter axles.

Well, Eaton 3 speeds did just exactly that. The only problem would be if the PDL was also engaged while it happened. Factory installs often have a interlock so the PDL can't be used if the axles are in high. With one in low and one in high, the interaxle diff has to make up the difference. as I said the 3 speeds of the 60's did just that. still they held up well enough. I have also heard (from Glenn A) that some heavy haulers retro-fitted 2 spd rear rear and a single front to add splits when hauling heavy, and they did ok. I never had a problem, and it would take major problem in the shifter for it to not shift. The air piston design is very simplistic and not much to go wrong. The earlier diaphragm air shift used a torsion spring like the electric shift do, and were more problematic, and the reason I don't like the electric and why Eaton dropped the diaphragm in favor of the piston unit.

This might help. From what I can see high speed (3.7 ratio) take a different differential case then lower ratios, so don't buy a lower ratio to re ratio to 3.7 https://www.dana.com.au/pdfs/parts-lists/AXIP-0085 Illustrated Parts List 461 to 653.pdf One advantage of the 2 spds is you use the same case halves for all available ratios.

Well, different things are "common" in different markets. 24" rubber is or was common down under and in the middle east but was not common outside the NY/NJ area in the US. 46K rears are common in dumpers but not road tractors in the US. You could spec whatever you wanted, but common spec for a road tractor was 34K for a long time then 38 and now 40K. Often when you go bigger on capacity you are required to go bigger on brakes as well, that can require other upgrades. So to keep cost down, truck were often not "Over spec'd" for their vocation. My guess is that 46K is the common spec where you are. In the US there are a lot of trucks that had 46K diffs, but not as many as those that had 40K. Rockwell SSHD's were common in dumps, I don't know the Eaton Dana share vs. Rockwell when it comes to dumps. Alot has to do with local laws, and allowed axle loads and length laws. Outside of "turnpike doubles" (2 45 or 48 ft trailers run on the turnpikes then broke into two separate units for off turnpike delivery) We didn't see a lot of high GCVW set ups. Heavy haul" was an exception. I did some of my heaviest moves with 40K rears with a GCVW in the 160-170k range. Those moves were well outside what the rears were "rated for" in GCVW, but did the job just fine, They didn't exceed the 20K/axle in the weight they carried. It is why 34K and 40K centers are all the same, only the side gears and axle shafts are different. Same for 46K and 56K centers. In full floating axles, the axle housing, bearings, brakes and axle shaft determine capacity more than ring gear size. Obviously, a 56K ring gear is going to be worked harder than a 34K even if they are powered by the same engine and transmission set, otherwise why pay for all the extra.

1st I'd make sure the 462 is interchangeable with a 461. In lighter diffs the 402 is not interchangeable with the 404. 2nd 46x and larger are less common here, but still a fair number. The adv road tractor has 40K rears, dump and off road will uprate to 46K That said I look to the major yards and gear shops. No idea what it would take to get some of these yard to ship down under.