Full Floater

I have converted a tandem R600 to a s/a The blown 38,000 Mack rears were replaced with a Mack RAD529 24,000lbs rear axle with the Mack 23,000lbs springs that came with it. The truck has an 18,000lbs front axle. 22.5 rubber I need (should) to determine a new lower GVW for the truck. I have not scaled it yet to determine it's new net weight. The door tag is blank and always has been and I see there are a few outfits online that are duplicating door tags on old truck. Not trying to do anything funny here, just would like a legible and accurate door tag with current and relevant weight numbers on it that apply to the truck now that it's a single. Any insight as to how I would best determine a "new" GVW for this unit? The old GVW was 53,xxxlbs. Im thinking the new GVW should be in and around the 36,000lbs range.

Got er done. Removed this and that, the valve is gone, more space to see what's going on behind the dash....the yellow and red still work as they are supposed to. Replaced a few air lines. Nothing's leaking. Im happy. Thanks folks.

Yes the blue one is independent of the yellow and red valves. There is a line from the yellow, going to the blue....not sure what it is, but im going to try to delete it. Simple is good.

I have a 237 that has had a fan clutch installed in place of a fixed fan. And they used a pile of washers as a hub spacer (which seemed to work but it looks sloppy). Im hoping to buy this spacer....anyone know if they are available anywhere? Also, say one wanted to buy a new fan clutch, just because.... is this what im after? https://www.woodlineparts.com/en-ca/products/pai-efc-1640b-mack-38mh416-fan-clutch-e6-21-00-26-00-fan-183125

Very interesting guys. Ya the one I have is a mechanical shift PTO. I have not engaged the PTO on that truck yet as it's just getting back together....but I will play with it both ways, main in N and aux in N. Im always a less confident with that aux box being in N position as they seem/feel less assuring as there isn't much wiggle room on the stick....so I always release the clutch real slow JUST IN CASE it's not actually in N

I'm new to the rear mount PTO on a 6 speed. Can I get any operating tips before I try to figure it out for myself? Does the main trans need to be in gear for engagement? Where should the aux box stick be positioned?

Im in the process of tiding up a bunch of hack job air line repairs and routing on a 75 R model. What are you thoughts on removing/bypassing the blue tractor parking brake valve, leaving only the yellow and red, as in more modern applications. The tractor is a straight truck and will never be pulling a trailer, so no real need to keep the trailer charged and the tractor brakes set for any reason, thus not needing the blue valve....unless it has a use that I'm not familiar with.... Just wanting to simplify things and keep the "what is the blue knob for" conversations to min with future drivers. Thanks folks.

For sure. I had to switch voltmeters, but everything else worked in regards to gauges and interior lights. Heater motor needed the wires reversed. Not sure about low air buzzer yet, but will probably need the wires reversed. I would have left it + ground, but I installed Jacobs 675 jake heads on it and they are grounded through the casing so I figured this is my calling to convert. Really wasn't a probably, just stumped on this signal issue. But it could very well be another issue

So far, everything has been trouble free in converting from positive to negative ground. I have only the signal lights left to get working. Im getting nothing from them, nor any power from the rectangular plug that hangs down and plugs into the signal-stat pigtail. The relay and all other relays on the relay board, are functioning. Changed flashers, to no avail. I'm suspect of this unit, mounted above the drivers side kick panel area. (this is a picture of 2 separate ones, one off of a parts truck). Anyone know if they have anything to do with the signal lights? Im at a loss as to where to look next, the harness is in tact and im hoping to leave it that way so I figured i'd ask here before I pull that harness all apart and make a mess, whilst trying to solve this problem. HOWEVER, I do not know if the signal lights were working in this truck, before biting the bullet and converting to negative ground and replacing LOTS of wiring, grounds and various things along the way in part of the restoration. So I may have had a problem to begin with, that I do not know about.

Thank you gentlemen

A proactive question for the future: Since I probably put the equivalent of several years of wear on the clutch brake as I was trying to free up and figure out this clutch issue; I anticipate having to replace it at some point earlier then I otherwise would. It is a 2 piece. Can I remove the release fork to aid in access to the brake? It appears that I can remove the release fork from the cross shaft, by unbolting and sliding the cross shafts out, freeing up the release fork. Am I right?

No video yet but I do have a couple before and current pics. Converting a 75 R600 Western from a tandem to single drive (Mack rear end and suspension) and putting a rollback towing deck on it. Will be in full time service. Should be on the road end of July im hoping.

HAHAHA, yup thats a pic of a spring AFTER removal! The other two springs were harder to get to and are not recognizable anymore, therefore. no pics of those two!

BIG NEWS fellas! I got it! It was the damn anti rattle shims. I managed (4hrs under the truck in the rain with all the picks and mini pry bars AND cutting torches in the arsenal); to get the pricks out. Instantly had proper disengagement of the clutch without even checking for final clutch and free play adjustment. Here's a pick of one of them. So for future reference. Do not install these things even if they come with the clutch kits and the instructions say to install them. Good side to this saga is, I learnt a lot about clutches and exactly how they work. AND I didn't have to pull the transmission! So....what was happening was, these shims were preventing the inter. plate from moving as it should. Must have been just the rear disk unlocking when pressing the clutch pedal to give me the partial disengagement

Ooooohhhhh!!! Sounds like something I can do away with?!?!? In exchange for using common sense and not compounding the brakes!

Well, the anti rattle springs go in after the int. plate is installed.

I will figure a way to get these ones out today, and will report back with the results. I think they may be creating just enough added resistance to hold up that plate...seeing how I was able to pry it back with a pry tool when the clutch pedal was pressed

I did, sorry for the lack of responses, been tied up with other clutch problems on a different truck. I got both the front service brakes and rear air supply to a relay valve plumbed into the delivery ports, which were on the bottom if I recall correctly. (Im not in front of it at the moment). there is a small line from the foot valve that is connected to the parking brake knob for some reason, that I plumbed into the foot valve wrong as the parking brake valve won't apply the maxi's now when pulled out. I think that line has to "dump" air somewhere and I have it plumbed into a supply port I think. Not sure on whats up with that but I got the service brakes to function so I could get that truck home. So for now, mission accomplished. Thank you

https://www.eaton.com/content/dam/eaton/products/clutches-brakes/clutch-installation-kits/eaton-hd-manual-adjust-clutch-clmt1351.pdf Here is a pathetic pic and install instruction of an Eaton anti rattle spring. It came included in the clutch kit and they are a thin steel shim/spring stock that gets pressed in by hand, between the intermediate plate and flywheel. They are snug but can be pulled out and pushed in by hand. There are 3 of them. Im assuming its to reduce any rattle or vibration that the intermediate plate may develop. Ok so I have now determined that the problem is in fact the intermediate plate sticking, just as you guys figured. I just discovered that there is 1 thru hole on the flywheel housing that allows visual access to the primary disk and flywheel side of the intermediate plate. With the clutch pedal depressed, I can get a thin pry tool in there and pry back the plate away from the friction disk. Viola! Its stiff and sometimes it will pry back and sometimes it wont. I accomplished this with the dog nuts loosened off. Since I was able to pry the intermediate plate back with a pry tool while the pedal is depressed, Im thinking nothing is installed backwards....just it's sticking. Something of note, the old clutch and the clutch on the donor engine did NOT have anti rattle springs. I installed them on this clutch as the instructions told me to. I think this might have been the mistake. I cannot get them out thru the pressure plate openings, as I thought I might be able to, unless I brake them apart somehow. Im going to try that. Im almost ready to take a die grinder or something to the spring in a spot or two to help collapse it and pull it out thru the pressure plate openings. Good tip and jabbing the clutch in and out while the driveline is spinning in attempt to free it up. I have been doing that quite a bit, along with sudden brake applications while the clutch is pressed in and only partly disengaging. I have done a lot and the situation isnt' improving. I even tried it with the dog nuts loosened a bit. I can see part of the dogs thru the flexplate openings and they all look new-ish as I remembered them looking and none are cockeyed or anything. So im pretty sure it's the anti rattle springs that I should have excluded. I will make a solid attempt at removing them and we'll see how the clutch reacts. If that fixes the problem without dropping the trans, you can imagine how happy i'll be! https://www.phoenixfriction.com/p-29245-crp-161c-5-anti-rattle-spring-for-14-in-spicer.aspx Here is a proper pic of the anti rattle spring .

Back it off as in turn counter clockwise and achieve zero free play in the peddle? I can try again, although I have already.

The anti rattle springs. Are they installed on all clutches. the instruction in the clutch pack made them sound optional for some clutches. I installed them on mine as that was my understanding on this particular clutch. They were snug enough that one would think that would hold up an intermediate plate. I wonder if I should take them out. I can see them at the right angle, I bet I can fish them out

I have, yup. At the moment its set up to spec with about 2'' of free travel on the pedal and 1/2'' between the TO bearing and clutch brake. But I have gone to zero travel and to the extreme the other way as well to about 3'' or more. Same symptoms. I'm achieving this by turn the 5/8 bolt on the clutch adjuster but have also set the linkage to zero play to get as much pull on the clutch as possible.

Good tips on making up a trolley for it. Same with using some all thread. I think in this case I will use some 4x4 wood or steel tubing across the window sills, and remove the floor panel and sling around the front and back of the trans. It was done this way on this truck before according to a previous owner. I just don't have the material on hand to rig up a decent trolly, nor is there a place near by that sells heavy trans jacks. I'd like to get started on the pulling of the trans asap if that's what ends up happening

Thanks fellas. Well, although uneventful and nothing bad happened, I did what was suggested to not do and loosened (about 1 turn) the nuts for the 6 dogs, on the outside of the flywheel through the little access hole for them. With the engine off, I pushed the clutch pedal in and out a few times, then re-tightened the nuts. To no avail. Still acting the same way. I was hoping that would free up a stuck intermediate plate. I'm almost tempted to try it once more with the engine running but that may be a bad idea.... Yes, good thoughts on the pilot bearing. It is brand new in this case and I really hope it didn't fail out of the box!

Lots of scratching my head going on here on this one!!