67RModel

Well you could do a couple things. If you get a hold of the Mack museum and request all the build information it may be contained in the papers you get back what the original designed GVW it was specd for. Information I gat back for my 1967 had the designed GVW, designed GCVW, typical payload and top speed desired at max GCVW (it is a tractor). Not sure if you would get the same information or not. I guess it just depends on how the dealer filled out the paperwork or if Mack engineering got involved and the numbers were recorded. You could look at the title and see what GVW its registered at and just assume that over the trucks life it was originally specd for what its titled GVW is. In the end it should not matter too much though. a 690SX is generally going to have pretty hefty specs. I would guess at least 44k rears and a 16k or 18k steer axle. But with the addition of drop axles one can increase the GVW significantly. You can basically make it whatever you want if you are cozy with an inspection mechanic. When I brought by 94 RD690 into PA from Virginia I had to get a PennDOT MV-41 form filled out and signed by an heavy truck inspection mechanic stating that the truck was capable of the GVW I was requesting the truck to be registered for. Its funny though the GVW on the Virginia title was 80,000 and I was wanting to register it for less weight at 73,280 (the most a triaxle can weigh in PA) to save some money on registration fees. I think it was just a formality on the notary's part. But consider if I had bought the truck as a tandem axle with the plan to put a drop axle under it. It would have theoretically been titled at 54,000 GVW. I would have installed a pusher axle on it to make it a tri and had an inspection mechanic inspect it and fill out an MV-41 stating it is now capable of grossing 73280. Not sure what goes on in Ohio though. Probably something similar I would think.

If you really want to get into the weeds with the "procedure" you can get get out your dial indicator when you are all done and check the end play of the hub center while spinning it and shaking it fore and aft. The acceptable tolerance I think is 1 - 5 thousandths of an inch end play 😂. But like other have said if your not blowing out seals regularly your wheels are not flying off.....your good. snug down on the bearing. Back off a little. and torque the snot (by hand) out of the outer lock nut.

And yes like everyone else has said. The Stemco Voyager seal goes in very easy with no special tools required. A block of framing lumber and a large ball peen hammer is all you really need. Of course you need to pay attention to what you are doing and tap it in with lots of care. I actually don't really know or recall what Voyager seal number mine crossed to but my original grit guard seal was 320-2110.......6" diameter.

Also a tip for anyone doing this type of job in a more or less shadetree scenario. Get a 3/4" drive digital torque adapter from Harbor Freight. I debated laying down some serious coin for an average quality 3/4" torque wrench that would go to 350+ ft*lb then I found this handy device for $70. You can basically turn any breaker bar into a precision torque wrench. Everyone has a 1/2" breaker bar laying around. Just get this tool and a 1/2 to 3/4 adapter and you are good to go. I have a 3/4" breaker bar and a long piece of 1" EMT conduit slides nicely over the handle for extra leverage. I was a little reluctant but I found many positive reviews on it that were not on Harbor Freight's website. It's also made in Taiwan not China so the quality and precision is good. https://www.harborfreight.com/34-in-drive-150-750-ft-lb-digital-torque-adapter-58707.html

I think there was one on here about 6 months or so ago and the guy wanted $100.00 for it. Lund quit making them a long time ago so they are are probably getting scarce but then again there is probably not a lot of demand for them anymore either.

OK I see this thread got some others doing wheel seals involved. I finally got around to getting into mine this past weekend. I buffed and cleaned the spindle very thoroughly with fine steel wool and brake cleaner and found no burrs or scoring. I assume the wear ring is probably much softer than the heat treated axle spindle. I have to assume the grit guard seal was not installed properly with the correct tooling. I debated purchasing the stemco tools to do the job correctly as they were not too expensive but in the end I decided to just go with a Stemco Voyager one piece seal. I did buy the two 3/4" drive 8 point axle lock nut sockets so I could properly torque everything (3-3/4" inner and 3-1/4" outer). I had a 2 sided tool that had both sizes (on on each end) with holes going through perpendicular to insert a bar for leverage. It is adequate for tearing down but there is no way to use a torque wrench on it for proper reassembly. Everything was covered in oil from the leaking seal so I separated the hub from the drum and steam cleaned the hub, drum, and the wheel. Got a new set of brake shoes (Meritor 4515Q) and new 3/4" grade 8 bolts to put drum and hub back together. Everything went back together fine. I couldn't find any information on the axle bearing preload and assembly procedure so I just seated the bearings to 200 ft*lb while spinning the hub. Back inner lock nut off and retorqued to 50 ft*lb and then backed off 1/4 turn. Installed keyed lock ring and then put the outer lock nut on to 350 ft*lb. Put on a new Stemco hub cap and gasket and filled with full synthetic Mobil1 75w-90 gear oil. Hopefully this problem is taken care of.

How did the 300 and 5 speed handle that much weight? I realize the maximum speed limit at that time was 55 and I think the world generally moved at a slower pace but you were probably at or over 80,000 pounds gross with that much payload.

Looks like all they liked to buy was flat top sleepers except the very last one. How long did you typically stay out on the road before coming home?

Yea I guess I don't really know what is going on here. If its a 6V system then running a 12V regulator on the 6V generator (assuming its in good working order) will work for quite a while. How long considering the extra beacons and strobe lights? I have no clue. I was thinking along the lines of a typical antique truck like a road tractor or flatbed that really only has headlights and a heater blower motor maybe and only gets driven a few times a month. These old B models had air wipers and no radio or power accessories whatsoever. And most trucks don't get driven in the winter or at night so really that just leaves the turn signals and starter. If its a 12V generator then just leave it alone unless its not working. If its not working just get it rebuilt so you can keep your power steering pump arrangement alone. No need to switch it to an alternator.

Then once the fields in the generator burn up (if it ever happens) just get them changed to 12V. No need for an alternator. Especially in this case when eliminating the generator gives you power steering pump issues.

Why do you want to make it into an alternator? A 6V generator in good condition will make 15+ volts when not connected to a battery. All you would need to do is install a 12V regulator in lieu of the 6V. Not the ideal solution but works very well for a long time. Eventually the fields in the generator will burn up by doing this but it will take a very long time considering how little electronics there are on a 1957 B model. Personally I would try that first....

This thread from a while back will help you some. You need to know your rear ratio before you do anything. If the trans is original to the truck its a T2050 I would think in 1986. By going to any Eaton trans or even a Mack 9, 10, 13 or 18 speed your top speed will suffer considerably as these all have a 0.71 OD vs your current 0.6. I don't think swapping the trans is easily accomplished. Even switching to a different Mack transmission would give you a lot of fitment / linkage issues. Its been discussed many many times on here. It depends on how important it is to you and how deep your pockets are vs just getting a truck already specd the way you want it. Most people love or hate the Mack 5 speeds and/or the variations of it (T2060, T2070, T2080, TRL107, etc.) Power to spare in 4th gear, dogging it in 5th gear on every small hump in the road you come to. And most guys cant stand staying in the throttle all the way down to 1200-1300 rpms before downshifting to 4th. They think they are loosing time or something I guess. My experience/observation is they are adequate for maintaining the posted speed limit or posted minimum speed, which in most cases feels too slow by todays "standards". If you are able to get into the proper mindset and understand how the transmission/engine combination are supposed to work they are fine. Quite frankly a different transmission probably isn't going to get you an additional load per shift or get you to your destination an hour sooner. But I do understand why a lot of people hate them.

I had a Pacbrake on a 12.7L series 60 Detroit and it worked extremely well. I realize a series 60 is overhead cam and not remotely similar to an E6. I am just attesting to how well they work on a similar displacement engine. I wouldn't be afraid of a Pacbrake if that's all that is available.

They are usually on the back lower edge on the passenger side. It looks like it has a horizontal side window like Mercurys do.

Is that a mercury sleeper on that rig?

Ok thanks for all the responses. I don’t have time to sit down and really digest all the info right now. I will get some pictures of the spindle and upload. I’m guessing this seal wasn’t installed properly with the correct tools. More to follow.

OK. How tight should the collar be? It slid off pretty easily with very little effort. Just a little wiggle and it slid right off, which would lead me to think it slid right on and no tool was required. Should there be a lot of friction between the collar and spindle? Perhaps is the wrong seal and collar for this application?

I have a leaking wheel seal on my drop axle. Axle is a 20,000lb non steerable Silent Drive, which I think is technically a Dexter axle now. Anyway, I tore it apart to change it and I found strange damage to the metal collar that slides onto the spindle first. The Seal is a Stemco 2110 Grit Guard. And the hub is a Webb 22.5 dayton spider hub. The failed wheel seal was only 1.5 years old and had less than 10,000 miles on it. What would cause the collar to get damaged like that? The seal itself pressed into the race looks completely fine (not visibly damaged) but obviously is seeping somewhere. Any thoughts?

I think if you give them enough $$ and enough time time they will do it. I think they have to have your old ones to work from though. They cant just make a set without a pattern.

Yes they can. They choose not to advertise it because it takes too long and ties up too much manufacturing space for other jobs I guess. They actually have a thread on the forum here of them doing it. Its several years old now.....

First I was thinking it was one of those Chrysler V8 deals since it looks like a light duty spec. Maybe an R400? The front hubs look almost like a medium duty weight rating. But the listing says diesel so I'm guessing its an 864 V8. If so, hopefully it runs and doesn't need anything major because I hear parts for those are basically non existent anymore.....

That dog should definitely be rescued. I think it will certainly follow you home LOL

Vicon Fabricating in Mentor, Ohio....a suburb of Cleveland.

Rather than do all that nonsense you could get brand new rails made. P.G. Adams in Maine or another outfit in Cleveland, Ohio I cant think of the name right now. Take your old rails there and get brand new ones with identical dimensions and hole locations.