Geoff Weeks

If you have 40 psi the next morning, I wouldn't worry about anything on the protected side (after the primary and secondary tanks) and concentrate on the system from the compressor through the wet tank to the inlet check at the primary and secondary tank. That is where your leak will be. With the drier purging every 20-30 sec it will be a big leak.

I agree, most inspectors don't even know what they are looking at. I've had two that looked at the inside of the spokes and the spacer rings as well as the outside in all my years and inspections. I am not saying that you'll run into that every day. I do know if you use the right parts you'll never have spun wheels or other wheel end problems. What you choose to do is up to you. I know many that will put aluminum "Budds" on short steel studs, and claim there is no problem. I know better and you'll never hear me say you can do it. I'm just trying to explain how it was done from the get -go. What to look for and how to select the right parts.

I ran 10R x 20 radials (Tubetype) and 11r 22.5 tubeless or 295-80 22.5 (same diameter as an 11 but higher load capacity) Can't say I noticed any ride difference between them.

Heelless clamp: Heel type clamp: 4" spacer band: https://www.napaonline.com/en/p/TWDSB4020K?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Towing&campaign_id=8911645606&adgroup_id=106416389246&adtype=pla&gclid=EAIaIQobChMIh83M_92TgAMV3t7jBx0njAqgEAQYAiABEgITJ_D_BwE&gclsrc=aw.ds&

New ones should be available, but not stocked. Special order item. There are two classes of wedges for duals. Heel and heeless clamps. Heeless should never have the heel end touch the spoke, Heel can have a small gap or touch, provided it doesn't touch until the nut is torqued to 80% of final torque. I would be surprised if the side with the narrow spacer has proper duel spacing, and the tires don't "kiss" on the sidewall when loaded. If you measure the flat part of the spoke, from where it starts to taper up in the back, (where the taper starts, don't include the taper) to the end of the cast spoke. If the measurement is: 6" try a 4" spacer band 6 1/4" try a 4 1/4" spacer band If it is less than 6" pay close attention to duel spacing with modern tires. My K-7 has a low GVW of 16500lb still uses a 6" wide (long?) spoke, the same as many modern hubs built for 11x r 22.5 tires. Spacer bands are "sized" by the outside measurement across the band, not inside width. These are the most common combinations. Also there are whole pages of wedges for duals with differing profiles and depths. It isn't a "one size fits all" type of assembly. The wedge must go over the end of the spoke and not be right at the end of the spoke casting when tightened. My 1942 IHC with 8.25x20 tires still takes a 4" band, I doubt that narrow band is correct. If you can find a casting number, or if it is branded (Mack, Gunite etc) see if you can find a part number in a parts book for the correct wedges and spacer.

Here, a DOT cop who knew what he was looking at would fail that. Yes, I have been though a few (very few) inspections where they knew enough and looked for wear, spun rim, and repairs to the assembly. Spacer rings aren't that much money, last time I bought some. I have never had a rim spin on something I assembled, but have seen plenty. I can see making that repair in the field, but not once back where the proper parts are available. Wouldn't pass inspection. In 20" and 22" stuff the spacer band will most likely fall in the 4" to 4 1/2" range (We don't have 24" in this part of the country, so no experience with those). Lighter axles found on smaller trucks may use bands that are smaller than 4", but that limits the tire and rim width you can fit. You say I am "over thinking" things, but you are repairing "spun" wheels? Hum, that lead to the question why are your wheels spinning in the 1st place? I did heavy haul, so carried above the normal weight on axles. Never had a wheel spin, even on hard brake applications. Here we had Webb, Gunite, Erie, and Dayton (and may be more that I am forgetting) making spoke wheels, there were different attaching methods and hardware used, some of which was compatible with other brands and some isn't. Just for example Erie used captive bolts and ball seat nuts, with wedges designed for that. They are not interchangeable with wedges and nuts for for stud based spokes with flat nuts. You CAN fit mis matched parts, just as you CAN fit mis matched lock rings on wheels, but in both cases it can cause a failure, rims may blow the ring out and kill you. Wheel end is just likely to spin and take out the valve, but could snap the stud and cause the loss of the rim/tire. For a while in the 90's (It may still be going on) Canada was having trouble with wheel end coming off trucks and killing people. If they found a wheel end problem they impounded the truck for a week (if I remember correctly) and it couldn't be moved without being repaired, even if repaired the same day, the week had to be "served" before the truck released. I take wheel end seriously, and have never had a problem with spoke wheels. I have had many problems with disk wheels. For a while IHC used the Erie system, my 1942 has them. If the spoke has been worn from loose rims, it is not a one-off time someone didn't install them correctly, it is something that has been going on for a long time. I question the maintenance practice of an operator with that. Parts that are mated and have no movement between them don't wear!

As with anything defective parts need to be replaced, but you don't change spacer bands when changing rims. The spoke determines what is required. If you have rims moving, you have a problem, defective or mis matched parts. If a rim spacer is damaged, replace it with the same width as the original. If you suspect a mis matched parts, then either consult someone who knows what should be or replace the whole assembly. All else fails, you can take the casting number off the spoke hub, from that you can determine the mfg, and contact them for the correct parts for that hub.

NO! the spacer and wedges are determined by the spoke hub, they don't change with the rim choice. Spacer sets the rim position for the wedges. The spoke length determines how wide the spacer that is needed and how wide the rims it can hold. Difficulty when buying used hubs without the factory spacer and wedges, is getting the correct parts.

I was still running 10R x20's on my trucks when I retired. I had a mix of tube and tubeless. Finding tubes on the road became the reason I started to phase them out. No rim or bead leaks with tube types. I ran long haul and carried a spare, regardless of construction.

Is there a market for a Spokes 101 thread? They used to be common but are not anymore. Anybody who says you "torque them straight" run from. There is a trick to getting them on, but they are strong and easy to change with hand tools.

Rear inner mounts with the stem out, rear outer mounts with the stem in. Front mounts with the stem out. It has to do with the heavy mount ring that the wedges clamp too, and what has the taper. Inside of the rear spoke has a taper that the inside of that ring mates too Outside rear, the wedges have the taper. Front spokes have the taper, front cleats hold the rim on the taper.

It does, the rim will only attach with the stem outward. If you are changing from 11x22 to 11x 24.5 you are stepping down one tire size. If, however, you are changing from 10x22 to 11x 24.5 you are staying the same size.

Likely a small cam NTA, but I am not a small cam guy.

The electric valve I was talking about was in the REFRIGERANT line not the coolant line. The Mack sleeper I have has that valve but I don't know the year. The valve is there so that if the bunk unit is off, no air flow through the cores, that no refrigerant flows so the evap core doesn't ice over. It is possible that the newer Red Dot units do it different than the older one. The system I am familiar with control the compressor based on the temp of the front evaporator. If there is less or no air flow over the bunk unit, it will cool below the frost point. You can't have a frost switch in both evaporators and have a workable system, but there does need to be a way to stop refrigerant (again, not coolant) flowing in the evaporator (again not heater core) when the bunk unit is not being used and the front system is.

I don't need a tinfoil hat to wonder if it was "disapproval" from the GRU that caused the site to go black!

I still hold hope it can be brought back, no knocking the warm welcome here, there was a lot on JOT that isn't here and can't be brought over without rebuilding the files that were on JOT. My feeling on ATHS is: they haven't changed from the time JOT was built, and until they do, I am not returning. I want to re state that I am very happy with the warm welcome given here to "off breed" posts, but it is 1st and foremost a site for the Mack brand, and that is how it should be.

Eddy, what is the longer term prospects for JOT? is it coming back or done?

Ok, I'll preface this by the fact I don't know your year, but most all bunk units I see have a solenoid valve that cuts the refrigerant when the bunk system is not turned on. That would be the 1st thing I'd check. should be powered when A/C is called for my the bunk control. Bunk units I am familiar with have their own Tx valve, so that is number 2 Next look at the unit itself and see if any refrigerant is flowing in the bunk unit. Look for temp change on the liquid line before and after the Tx valve. If none, then there is no flow (likely number 1) if there is a temp drop but the outlet tube is warm, it may be low on refrigerant and the front is 'hogging" all the liquid.

Heat was there when just the bearings were "hand packed" with no "extra" grease in the housing, so that isn't the cause in this case.

Terms can get confusing esp when "slang" and regional differences come into play. To be clear, I am taking about a driveshaft mid ship bearing and not anything contained in the rear axle housing. Yes the left and right bearing inside the axle housing are also called "carrier" bearings, because they support the (carry as it were) the differential, which is housed inside the carrier itself. Clear as mud, and the more I try and spell it out the more it will confuse things! Most longer wheel base trucks today have multiple shafts sections with the back end of each supported by a driveshaft carrier bearing, often suspended from above. Unlike the modern practice of hanging the bearing from two bolts, this one passes through the crossmember and is held in with a ring of 6 bolts This truck has the carrier or "midship" bearing where the shaft passes through the frame crossmember. The bearing must "float" on the shaft to allow for minor fore and aft as well as concentric adjustments of the whole housing The double taper roller is supposed to have .005 to .008 of "slop" in the bearing assembly, so no pre load in this application. It runs in grease, and that may come into play as well. Bearings run in an oil bath can remove the heat, those in grease can not. (or not as easily). To adjust the bearing, you select the spacer ring that provides the desired fit. Too tight and you risk the whole bearing spinning in the housing, too loose and you will introduce run-out and therefor vibration into the shaft. The problem I was having was, after running the shaft at max speed for just a few minutes the bearing housing was getting so warm you wouldn't want to keep your flesh on it for more than a few seconds. It may be normal, or it may not, I have little to compare it to other than wheel bearings, which turn slower but don't generate anywhere near that amount of heat after hours of running.

Pinion bearings are a good example of bearings that run "back to back with a preload and high (relatively) high speed. In the case of the carrier bearing, they are factory (bearing mfg, not truck mfg) set and sold that way. I don't know if over the years, the roller races have been changed, they're not supposed to be, the bearing gets changed as a unit. It is made up with "off the shelf" cone and a double cup outer race, but the spacer is selective fit.

I can think of plenty that run with pre-load. Spec for this bearing is .005-.008 measured at the outer race. Just feeling by hand, I think it is tighter than that.

On mine, the dual rear windows in the cab slide down, something I had not seen on any other truck. Spring loaded up with a friction lock to hold open. Can't believe the condition of the cab for a truck of this type. few if any dents and almost no rust. The frame is another story, ,any welds and changes. Anyone wanting to make it into a driveable truck would be best to mount the sheetmetal on a newer frame.

Still haven't checked the carrier bearing. When I was diagnosing, I dropped the rear shaft and ran the engine and trans in top gear at rated speed and noticed the bearing housing got warm enough you couldn't hold it for more than a few seconds. I figure 125-135 deg F. It got this hot in a very short time of running at speed. This truck uses a double taper roller with a spacer supplied by the bearing Mfg. I ended up replacing the bearing (s) although they looked ok. I'm not sure if it was on the tight side or not. I saved the old bearing and put a N.O.S. bearing in. I need to put the bearing in a press of vice and see if it has pre-load or any play. I think I might mic the present spacer for the old bearing and order one a few thousandths thicker. It doesn't use the more common type of ball bearing in a rubber mount. It has a tubular housing that holds the double bearing and the housing is mounted in a "clamshell" mount with a rubber ring between the housing and clamshell.

I guess shafts with cross and bearing type joints set up a standing wave at one RPM (critical speed). The size of the shaft and the length determine when that happens. To avoid it, you can make the shaft bigger or shorten each section.. Also they found that at exactly 1/2 the critical speed you can also get a vibration so while you can pass through that speed, you don't want to run at that speed for very long.