Geoff Weeks

I can strongly recommend going with an electronic speedometer. Makes life easy. Cost isn't much and the yoke for electronic seams to be available. If you must keep the mechanical and are willing to spend the cash to keep the original speedometer, Dakota digital makes a steppermotor cable drive to convert electronic pulse to speedo cable drive. Cost plenty though. depends on what your situation is. For a working truck, I would go electronic and be done with it. Hobby or restoration is a different matter. Cable drive is only going to get harder as the years go by. I used to be able to get them made up in Omaha, no more, Colorado, Texas and Michigan are the closest places now. What exactly is the problem with the present yoke? Can it be repaired?

Everything I find so far says it is discontinued, so repair or used may be your only option.

this might help: J300P-10 (patsdriveline.com) Interestingly the catalog shows the speedo gear as integral on that model trans? Not seen that on other transmissions, they list one for mechanical and one for electronic. Learn something new every day!

I would still look it up in the Spicer catalog, often I find people have one sitting on the shelf, can't remember what it was ordered for and just want it gone. Sell it for used price for a brand new yoke. Once you have the yoke number you can search it both ways, by application and Yoke number. You'll need to know what series U joint you are using either way, the Spicer catalog will help with that, they list the dimensions.

Agree with the above. Spicer yoke catalog should get you the right yoke if you truly need a yoke.

I always went about it the long/cheap route. I bought a used truck and then outfitted to what I wanted, often with used parts. I would imagine that as long as the parts are still available that route would still be an option. IDK with air disks taking over how many spokes that can handle disk brakes, would be available? I know school bus chassies use them a lot, not sure on heavier trucks?

I've heard that alot, but it has always been by non technical people. I haven't heard any conclusive proof. There are many reasons why I doubt the "corrosion" explanation. My Uncle was a corrosion specialist for USS and I wish I had thought to put the question to him when he was alive. 1) most corrosion is caused by air and moisture/salts external to the wiring, new sealed lights more or less prove the point, now the corrosion is not at the light bulb but at the connection, again where air and moisture can attack it. 2) we still have as many connections with either polarity and while the direction of flow at each connection is reversed you still have steel to copper, so if it would make a difference it would just move the corrosion point not eliminate it. 3) some point to galvanic protection of pipeline and bridge structures as proof, this misses the point that vehicles move through the air and to be effective you would have to charge the air around the vehicle to have any effect. 4) when positive ground was popular, little was known of galvanic corrosion or the effect or direction of electron flow in a dc circuit. With old simple vehicles, it just plain didn't matter, most gauges didn't care (later balanced coils gauges do) so it really didn't matter which way around the vehicle was. In the 6 volt era, you saw a lot of positive ground. When the switch to 12 volt as the common vehicle voltage is when we see negative ground become popular. It think it was more to differentiate from the 6 volt vehicles. Once semi-conductors started being used, it cemented negative ground. For some reason it is cheaper and easier to mfg semi conductors in that polarity. Old tube radios used vibrator coils to make a static inverter essentially isolating the radio power feed from the vehicle. I had an old Telafunken (sp?) out of a '55 Porsche that could be run on both 6 or 12 volt, positive or negative ground. Once transistor radios came in most were negative ground. An alternator requires diode in both polarities so no gain or loss there as to vehicle polarity. L/N an early maker of automotive alternators, went with "case neutral" construction so could be used on either polarity, most other mfg made the case one polarity or the other, requiring a different part number for + or - ground. With the abundance of semi-conductors in a modern vehicle, negative ground is almost taken over. You did ask Swishy.

Correction, I am wrong, it is not a U200 Timken, although it looks a lot like it. It is CRD117 Mack. I didn't know Mack made frontloading double reduction, all I know are the top loading. Bearing and seal kit: 205SP70 According to Weller for what that is worth. Quick search comes up with: PAI Online (paiindustries.com)

Wow, old Timken axle. You might find a rope seal sandwiched in the front bolt on plate. I haven't pulled one apart, I'd have to look if I have any parts or service that cover that old "U" axle.

This type of system is called a "bottom fill" the expansion tank, whether on the top of the radiator or somewhere else is not open to the top tubes of the radiator or, in a cross flow (which is what I believe you have). The idea is the radiator stays full to the brim with coolant, while any air gets forced through the small vent lines to the expansion tank. When you fill the expansion tank, the coolant flows to the lower (waterpump inlet side) hose. as the block and radiator fill, the trapped air flows out the small vent lines to the expansion tank. With the engine running, a very small amount of coolant is forced (along with any air) through the small hoses to the expansion tank (sometimes referred as a "de-aeration tank), and the coolant, now free of air, flows back down the large hose and back to the waterpump. This means the radiator doesn't have to be the highest point in the system (expansion tank does) but does mean any points that could trap air need to be vented to the expansion/de-aeration tank. Often those points are the upper water rail near or at the thermostat and the upper or hot water out radiator hose. On a down flow radiator, often the upper hose/top tank vant can be internal if the de aeration tank is mounted on top of the radiator, just a small hole drilled thru will allow the air to bleed out. This prevents air from being recirculated when the 'stat is closed and hot-spots in the engine.

Me too, plus Iike the ease of tire changes, only 5 or 6 nuts and inner or outer can be changed. One of my K's is on disk the other spoke, I don't think I'll change it out, but if someone really wanted disks and offered to swap spokes for disks, I likely would.

Funny that, spokes used to be the "fleet option" back in the day. Most all the fleet trucks and trailers ran spoke, Disk were the O/O option because they were shiny. Several of the companies I was leased to had spokes on their equipment up into the late 90's

several ways to make an educated guess. 1) if the engine has an alternator and not a generator look to see what polarity is grounded, Alternator care about polarity so should be marked. 2) if a generator the regulator may be marked as to polarity 3) if the truck has an ammeter and no alternator, disconnect any radios and electronics and hook up a battery and turn on as many lights as possible and see if the ammeter points to - or +. If negative, then you have the right polarity, if it points toward + you have it backwards. If the vehicle has an alternator, disconnect all wires before doing this test. 4) look at the terminal ends at the battery, larger terminal goes to +, the one with the smaller hole is - (this is for old post type batteries.) Since old trucks with generators and no radios they will not care and can be switched at will.

I ran into a few that were NLA (trailer spec) and ABS has been around for a long time, I had a trailer with ABS and spokes. There are only a few different bearings/spindles in use today on drive axles. It only takes a little machining to accept a "tone ring" for ABS, so I would imagine all are machined to accept one even if it doesn't have one.

I still have it, I need to paint the frame, put the 5th wheel back on, de-identify and then sell.

I think as long as the hubs are available they could be special ordered. Right before I retired I saw a brand new side dump trailer being delivered somewhere with 24" rubber on it (hub pilot). It might not be a RPO but I would be surprised a mfg would say 'No" to a request for them. Might delay delivery for a while.

The baby moons were the only "Bling" on my trucks, the nut covers got a little grease on the inside to keep the rust off the studs. Getting hard to find 1 1/4" nut covers. The hubs in both pictures need a re-paint, but both were hard working trucks, not trailer/show queens.

Somewhere I have an exhaust tube adaptor, it is just right for installing speede sleeves on front axles. I had to paint it red so it didn't get used on some exhaust job.

Here: Metal Trailer Hubcap Mounting Bracket For 8 Inch Rear Hubcap On Trailer Axle - 4 State Trucks

The bracket that allows you to mount them on a trailer, work just fine on the front. They bolt on over the oil hubcap and have 4 prongs that the babymoons snap onto. Unlike disk wheels the center of the hub is inside of the outside of the tire. BTW my Marmon and my '89 IHC had air start and spoke hubs.

Needs "baby moon's" on the steer hub also! Like them on the drives

Spokes and disks were competing back in the 40's and 30's likely before that. I have two 40's K IHC's one on disks and the other on spoke. I pulled Motor Wheel hub pilots off my Marmon and installed spokes after too many cracked wheels and studs. The one time I spec'd a new vehicle (Trailer) it was with spokes and sliding tandem. Salesman tried to talk me out of it, said it wouldn't have resale value, he was right, the trailer was crap, the wheels were the best part of it!

I know finding them is difficult, when looking for replacements. Many of the older trailer types have been discontinued. As the hub/bearing size and spacing has been consolidated on drive axles, it shouldn't take many part numbers to service most drive axles. I converted most of my tractors to spokes.

In the 50's Buda had their 844 diesel that would put out around 400 hp (when most other diesels of the day were below 300 closer to 200) and get close to 6 mpg (when the others were around 3), sound like it should have taken over the market. Customers loved them when the ran, but bankrupted most because of breakdowns. Alis Chalmers bought it and tried to solve the problems, calling the engine the 'BIG AL", you don't see many of them in trucks now do you? If it can't go the mile with the freight, all other stat's don't mean much.

You can add my name to the list of people who are cautioning against pushing it too far. I made my living with engines that were 30-40 years out of date, even though they were the Cummins 855, the most common engine used in trucks, there were some parts that took some time to find 40 years on. Most truck engine can go 15-20% over stock and keep together long term. Once you go much over that, you are asking for problems. Unless your customers are far different then mine, they never cared how big an engine I had, only that their freight got delivered when they needed it. I pulled load exceeding what you do, over some of the same passes you pull. Biggest problem when turning up engines is keeping them cool, both coolant and EGT. Pulling a long grade, you'll find it real quick. One of those track pulling engines wouldn't last a mile pulling a grade with a full load. If you want to build a truck to "play with" and have deep pockets, have at it. If you are building something to make a living with, then stay close to stock. My customers never cared that I pulled up in a 40 year old cabover with 380-430 Hp, (turned up 350's and 400's) just that I turned up on time. Customer isn't going to care you are 1st to the top of the grade, if it means you are broke down a lot of the time. Parts stash at home means little if you are on the side of the road with a loaded trailer and need to be towed. I worked train derailments with a 238 hp powered Fleetstar, and hauled 170,000lbs with 400 hp. It is far too easy to break things with high hp than low, I moved those 170,000lb loads through a 14 organic clutch!