Geoff Weeks

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.

Air shift is my favorite, Yeah, push the button down, while under load, let up or step briefly on the clutch and it down shifts. Vacuum is my 2nd with electric being last on the list. I have the Marmon with air shift and two K-7's with vacuum. Marmon has a 3406, the K-7's are 269 gassers. Like anything else, a little time in, it becomes second nature. Eaton held the patent of the planetary gearing in the 2 spds, Timken, Detroit, Rocknwell also made 2spd's but they were a double reduction units that either hung off the front or on top like a Mack. The advantage of Eaton's design is the whole thing fit inside the ring gear, the disadvatage was you were limited in what planetary ratios would fit inside the ring gear, so most often they are around .73 between low and high. Eaton, Dana and Spicer rears are all the same company (Dana Holdings Corp) now, Spicer sold of the trans business to TTC, because Roadranger was part of Eaton, so they would almost be a monopoly if both Eaton/Roadranger and Spicer heavy transmissions were one and the same company. My air shift are electric over air. Air solenoid controls air pressure to the two shift cyl on the axles. You could use an air knob on the stick, but you still need an electrical signal to the speedo or speedo adapter to keep the speedo reading correctly in both ranges. Since I needed an electric signal anyway, I went with the typical "red knob" on the side of the trans stick. Also I had a 15 speed trans that needed its own shift knob. I could have made it all air, but it would have been a rats nest of air line coming up the stick. I agree, they should be used more, and if I ever had the chance to spec a truck the way I like, they would be top on the list. Doing more of the reduction at the rear, means you don't need as heavy a driveline, like you do when most the reduction is done at the trans. Like a two or three stick, you can't be in a hurry, but once you learn them, they are great.

Here is a pic of the 402 housings and the notch I am talking about. You can clearly see the cut-out on the right side for the shift fork Edit: left side of photo, right side of front housing. You are looking at front housing faceing toward the rear of the truck.

No, it is not hard, done several myself. Lifting from the top (if you can) is better than dropping out the bottom. Neat thing about 2spd gear sets, is the ring gear is bolted to the carrier, so if you are comfortable setting up final drives, it is an easy job to change ratios. You have the selective fit on the pinion bearing to deal with and the press on spigot bearing on the end of the pinion, but all those part can fit in you boot or footwell of a car and taken to someone if you don't have the equipment to do that part of the job. Single speeds often come with the ring gear riveted to the carrier, you have to drill out and install with a bolt kit in the field. OEM use a big rivet "squeezer", but replacements are done with bolts. Make much more sense to re-use you housings if at all possible, not only do you not need to find housings that are set up for your suspension, none of the wheel end/ brake parts need to be touched. Just zip out the old and replace with the new, even the 1/2 shafts are re useable. A note on ratios, the split between low and high is almost exactly the same as dropping one gear stick position (not splitter), so many of the potential ratio's will overlap, two way to arrive at the same thing! I use mine in low for starting, than run up through the gears to top gear, than switch to high for the last two ratios. When climbing a hill it is the reverse, drop two, downshift and run the hill in direct-low. Keeps the heat out of the trans while pulling hard.

I wonder if Mikey Harbison has anything? His Dad used to quite a collection of odd stuff.

Eaton use family of gear sets. The 402's are the same center section as a 341's The 402's have a weight cap of 40K while the 341's are 34K, the only difference is the side gears that the axle spline mate into. As you would expect as the weight rating goes up, the size of the axle 1/2 shaft does also. For my purposes, this means I could use any 2 spd core from early DT340's to the latest DT402's, When I re ratioed to my chosen ratio I installed 402 side gears and then just popped the 2 spd center in place of the single 3.90's I removed. You can not build a 2 spd out of a single spd core, the carrier casting is not made the same. You need 2 spd cores to build a 2 spd axle. I went with 2spds because I could find old cores cheaper than modern single speed. As it turned out I had a 2 spd (17200) in a single axle tractor that I could re ratio and used in my "rear hole". I just needed a front core from a tandem to re ratio and I was set. I found a DT341 core and made the swap I went from 3.90's to 4.11/5.61 (? I don't remember the exact low ratio, could look it up) and gained .75-1.00 MPG. I had a 425hp 3406 and a RTO14615 in front so same .73 O/D you do, on 10.00x 20 rubber. So to recap, you need some 2 spd cores, and the rear rear is the same as use in SOME single rear trucks. The difference between rear diff "families" is the lighter (34K-40K) use either 16" or 16.5" ring gear and the larger use (I think?) 17" or 18" ring gear, obviously the houseing and center casting are different to accommodate the larger gears. The same center section was used in 46 48 and 56 (46k 48k and 56K) rears with differing side gears in each. I think the 18200 single rear would be of the same "family" as your 46's. The question you have to answer is if you housings will accept a 2 spd center? For example: the bolt circle and housing size is the same on a set of IHC 472's and Eaton 402, and you would think you could sub in a Eaton but the area around the axle line is notched out to allow the shift fork on DT and DC axle models on an Eaton housing, it is not on the IHC. I don't know if all Eaton housing are built like this. Mine were in a Marmon, a low production truck, so I would guess Marmon would order only one Eaton housing for use in all Eaton rear trucks. They would only need to stock one, and drop in whatever center the build sheet called for. I have heard conflicting info from yards and builders as to whether all Eaton housings are provided with the cut-out or not. Some say yes, other say no. Mine were. In your case, where I don't see a 2 spd 462, I would check your housing before ordering a set of cores. On the housing at the center line where the axle goes there are two bolts (top and bottom) and the axle center line passed between them. on the rear rear left and front rear right, the opening will have a [ or the right of front and ] on left of the rear instead of being ( ) {equal on both sides} in other word it will look like [ ) on the front and ( ] on the rear. You can only see this with the center section out. If this is not clear I can try and get some pic's of a set of Eaton 402 housings.

Ah, bad new, I can't find a DT 462, if you had 461's you could replace the DS/RS 461 centers with DT 461 centers. Eaton numbering goes like this: D= front tandem or tandem set DS tandem set single speed DT tandem set 2 spd DC traction control single If you had DS 461's DT sets were made. But since 2 spds have dropped from favor the latest axles didn't have 2 spds The DS 402's (40K singles) could take DT 402's or any center in that "family", and be made into a 402 by changing the side gears to match the axle shaft. Same held true for the larger 46K axles. I don't know if the larger axle housings are the same as the smaller, with the "notch" to allow traction control or 2 spds. like the smaller housings were, the single speed housings will accept 2 spd or traction control centers. If you find that 461's will bolt into your 462 housings, than there is the chance that you could get older 2 spds the high/low ratio is always the same split, it is fixed by the planetary ratio inside. They come in most all the same ratio's as singles do in high so yes 3.70/5.05 or 4.11/5.61 would suit. n 1st thing before you go on a search, is talk to Eaton rep or a knowledgeable gear shop to tell your options on the DS462 "family". of rears. This is exactly what I did on my truck, replaced DS402's with DT402's I built up from cores.

My Dart, the only truck I have with more than one stick, the aux is to the right of the main. That gives more room.