Will100 Posted Sunday at 07:19 PM Share Posted Sunday at 07:19 PM First the story My grandfather assembled Mack trucks for 34 years and there has been talk in the family on and off for years about buying a B model Mack. Long story short, he bought a "toy truck" for me for Christmas. The truck was built January 6-7 1964 for Gateway Transportation in Saint Paul, Minnesota. In 1974, it was acquired by a local fishery who put a Ramey pallet loader on the truck. The truck has never seen pavement since. The pond ice doesn't get thick enough to kill the fish anymore and the truck was just setting around. The old guy who has worked there most of his life would start it up to keep it running until one time he tried and it just cranked without firing. Not sure how long ago that was, but it was within the past 5-10 years. I acquired a set of solid rims & tubeless tires and had it towed to my house. I'm starting with the brakes and axle assemblies to avoid the temptation of driving it without brakes. It has 15"x7" wedge brakes. While I'm at it, I want to address the leaking seals on the carrier assemblies. I'm not sure where to get parts. I don't just see parts list/diagrams. Also I am not aware of a parts locator like the NAPA/Autozone has on their websites. Any advice on where to start? I did purchase a set of shop manuals. All three manuals has "TS442" on the back. I believe they are the ones I need. Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/ Share on other sites More sharing options...
Will100 Posted Sunday at 07:40 PM Author Share Posted Sunday at 07:40 PM The truck where it last sat. It's a project! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567775 Share on other sites More sharing options...
Will100 Posted Sunday at 07:43 PM Author Share Posted Sunday at 07:43 PM Finally home and starting to figure out how air brakes work. It's been off road only since 1974, so the brakes have been hacked on and cobbled back together a few times! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567776 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 07:51 PM Share Posted Sunday at 07:51 PM Good for you for attacking the brakes 1st. I would have put them ahead of rim changes. Wedge brakes have their share of detractors, and not somewhat without reason. When working properly, they are capable of stopping the truck with smaller drums and narrower shoes all while using less compressed air, all while being self adjusting decades before auto slacks where common. That is the good. The bad is, they have a tendency to freeze up if the wedge piston seals are damaged or missing. From your pictures I would say they are missing. The key to them is no rust or oxidation, plenty of lube on the adjuster and good "soft" rubber seals keeping the moisture and brake dust out of the actuators. By attacking the brakes first, you will know if you can bring them back. Be very careful to note how things are assembled, and make sure you can get full kits to bring it back. There is a little ratchet spring that turns the adjuster depending on how much movement is required for the linings to contact the drum. When they are all restored, they can be very good, but if it sits they freeze up easier than S cams. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567779 Share on other sites More sharing options...
Will100 Posted Sunday at 07:52 PM Author Share Posted Sunday at 07:52 PM Not exactly sure how to interpret the carrier data, but I wonder if it got another rear end when the loader was added. There is a weld on the frame between the cab and axles. I haven't measured the overall length, but I think it may have been lengthened. There are no holes anywhere for the 5th wheel that would have been used by Gateway originally. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567780 Share on other sites More sharing options...
Will100 Posted Sunday at 08:01 PM Author Share Posted Sunday at 08:01 PM Geoff Weeks, thanks for a strait forward overview of wedge brakes. I've read some very strong opinions in here against them. Initially the truck is just a toy and will only be driven on the weekends for fun, and if it does do any paying work, it won't be frequent. My preference on antique toys is somewhere between original and functional, so I'm not sure if the wedges stay or not. I lean towards keeping them as long as they can be rebuild for a reasonable price. Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567781 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 08:13 PM Share Posted Sunday at 08:13 PM (edited) It is almost always cheaper to go back with what it came with. It may look simple to change the spiders, but there can be a ton of stuff that has to be changed that isn't immediately evident. Like: the flange the spider bolts onto, being different for wedges than S cams or even being "clocked wrong" for S cams. What you have now, did at some point in its past, all work together. When you start changing stuff, you may find what "looks like it should work" doesn't. I have one truck with Wedges on the front (built that way). Unless you have an exact parts truck with the same rears and suspension but with S cams, there are a lot more questions than answers. Not only with the spiders be different the drums will be also, S cams need 16.5 x 7" to do the same work. Every once and a while I see "loaded spiders" for sale on the internet for wedge brakes, as the military used them A hobby truck that isn't going to be worked hard and put up wet, should be fine with wedges. Edited Sunday at 08:14 PM by Geoff Weeks Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567782 Share on other sites More sharing options...
Joseph Cummings Posted Sunday at 08:16 PM Share Posted Sunday at 08:16 PM Every wedge brake tractor I converted to cams the first time anything went wrong with them. And we had a lot of ex Matlack and Chemical Leaman trucks Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567784 Share on other sites More sharing options...
Will100 Posted Sunday at 08:18 PM Author Share Posted Sunday at 08:18 PM Thanks for the info. I have a chevy truck that I tried to do a few things to without removing the throttle body and OBD1 computer. Long story short, it runs, but not right. Some things are better left factory. Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567785 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 08:31 PM Share Posted Sunday at 08:31 PM (edited) Kits go for as little as $32 surplus on the internet to over $1000. A lot depends on what kit fits your application and what you can find. Which is why I suggest takeing yours apart, assessing what is re-usable and what is not. $1000 per wheel end is very high, but before you consider changing to S cam, you'll need to find old (likely obsolete) drums that fit your 1964 hubs. Back then there were a lot of drum styles and not all are still made. You can't re-use the drums you have because of brake shoe diameter. If your current drums are serviceable, that knocks a big chunk off the cost of getting working brakes. I bet if you look, you can find a FIO Military manual for wedge brakes that will help you decide what is reuseable and what is not. Edit: I ran into the drum issue a while back. I had some old hubs, and the drums for that hub were NLA from the drum mfg's. I found a set on the shelf in Montana store of a parts house I had an account with. I stopped off on my way through as shipping would have cost more than the drums. They had ordered them for someone who never picked them up, and they sat in inventory for years. Had I not been able to procure the drums, I would have had to buy hubs as well as drums to convert to something more modern. This was on S cam drums! Edited Sunday at 08:38 PM by Geoff Weeks 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567786 Share on other sites More sharing options...
cruiseliner64 Posted Sunday at 08:40 PM Share Posted Sunday at 08:40 PM Welcome to BMT.Thats is a big project you have there but with a bit of time it'll make a great truck.Good luck with it. Paul Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567787 Share on other sites More sharing options...
Popular Post 70mackMB Posted Sunday at 08:54 PM Popular Post Share Posted Sunday at 08:54 PM My son's ex Consolidated Freightways trucks, trailers, and dolly all have wedge brakes. Once repaired and maintained correctly they will work fine. When we went to the ATHS national show in Kentucky a few years ago with his COE Freightliner. He took a manual about wedge brakes and how to adjust them with us. ln case we ran into a DOT inspector that didn't know what they were. lol .....Hippy 4 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567788 Share on other sites More sharing options...
Joseph Cummings Posted 23 hours ago Share Posted 23 hours ago 1000 per wheel is insane. You could buy a whole cuttoff with cam brakes for less than half that. I guess to make it period correct, you'd have to use the narrow brakes with the bolt on lining. Those narrow shoes with the drums, spiders, ect is the kind of stuff that hits the scrap when you're cutting up trucks Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567807 Share on other sites More sharing options...
terry Posted 22 hours ago Share Posted 22 hours ago 7 hours ago, Will100 said: Not exactly sure how to interpret the carrier data, but I wonder if it got another rear end when the loader was added. There is a weld on the frame between the cab and axles. I haven't measured the overall length, but I think it may have been lengthened. There are no holes anywhere for the 5th wheel that would have been used by Gateway originally. Original 4:50 rears have been regeared to 5:73 ratio. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567808 Share on other sites More sharing options...
Joseph Cummings Posted 21 hours ago Share Posted 21 hours ago 1 hour ago, terry said: Original 4:50 rears have been regeared to 5:73 ratio. Terry Depending on what the trans is, he might want to just change the whole cutoff. If that truck had a direct trans in it 5.73 isn't going to give much road speed. It could top out at around 40 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567809 Share on other sites More sharing options...
Will100 Posted 15 hours ago Author Share Posted 15 hours ago 5 hours ago, Joseph Cummings said: Depending on what the trans is, he might want to just change the whole cutoff. If that truck had a direct trans in it 5.73 isn't going to give much road speed. It could top out at around 40 I am glad I came here before spending on parts! I believe it still has the factory 10 speed uni-shift. The spec sheet says it should be a TRDL-725. What top speed would that give me? If I can't get 55-60 mph, then I'm going to rethink my plans with this truck. Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567815 Share on other sites More sharing options...
davehummell Posted 14 hours ago Share Posted 14 hours ago My B model had a low rear and a duplex out on 81 I was a sitting duck couldn't get more then 50 miles an hour and in todays traffic that isn't good I slid in a 373 rear and that was a lot better had s- cams and about new brake shoes and good drums. The duplex started to jump out of nineth gear so in went a 13 speed triplex and I can cruze 70 on the highways. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567816 Share on other sites More sharing options...
67RModel Posted 13 hours ago Share Posted 13 hours ago (edited) 16 hours ago, Will100 said: I wonder if it got another rear end when the loader was added. There is a weld on the frame between the cab and axles. I haven't measured the overall length, but I think it may have been lengthened. Looks like it was a factory tandem since the build data says B67 "ST". The S means tandem. And T means factory tractor. Was probably lengthened for the pallet loader. A wheel base should be listed somewhere in your build information. Edited 13 hours ago by 67RModel 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567821 Share on other sites More sharing options...
Geoff Weeks Posted 13 hours ago Share Posted 13 hours ago 2 hours ago, Will100 said: I am glad I came here before spending on parts! I believe it still has the factory 10 speed uni-shift. The spec sheet says it should be a TRDL-725. What top speed would that give me? If I can't get 55-60 mph, then I'm going to rethink my plans with this truck. As built now I think 60 is not obtainable. Before you do a bunch of guessing, confirm what ratios you both rear and transmission. Do the math and then decide what is the most cost effective way to get what you want. 11x 25.5 tires have a 501 rev/mile diameter. Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567827 Share on other sites More sharing options...
Joseph Cummings Posted 11 hours ago Share Posted 11 hours ago (edited) 4 hours ago, Will100 said: TRDL-725 If that and the 5.73 are correct you are going to end up with 392 RPM at the wheel. Depending on tire size probably a few MPH +/- of 40 A "10R20" tire typically has around 497 revolutions per mile. Edited 11 hours ago by Joseph Cummings Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567843 Share on other sites More sharing options...
Joseph Cummings Posted 11 hours ago Share Posted 11 hours ago A set of 4.17 ratios (common in maxidyne 5 speed trucks) will give you 65MPH on like 10r20s or 11r22.5 But now you have to think if first is low enough. Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567847 Share on other sites More sharing options...
Jack Mack Posted 10 hours ago Share Posted 10 hours ago So the stamping of ratios on diffs means it was changed from 4.50 to 5.73 gears? Possibly when it was changed to be an off road truck perhaps. You are doing important stuff but cleaning up what looks to be the aluminum radiator and fender piece, will give you something to look at and think we’ll get this someday! Truck looks pretty good for the life it has lived……Jack 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567851 Share on other sites More sharing options...
67RModel Posted 10 hours ago Share Posted 10 hours ago Assuming those new tubeless tires you put on are 11R22.5 (498rev/mile) then you have 5.73 rears and 5th gear is 0.78. In a duplex transmission hi is direct (1:1) and low is underdrive. So with all that said on a 2100 rpm governor you will be doing 56.5 mph theoretically on paper. If those are 11R24.5 then you will be a few mph faster at 2100 RPM. FYI..... Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567852 Share on other sites More sharing options...
Joseph Cummings Posted 10 hours ago Share Posted 10 hours ago 9 minutes ago, 67RModel said: Assuming those new tubeless tires you put on are 11R22.5 (498rev/mile) then you have 5.73 rears and 5th gear is 0.78. In a duplex transmission hi is direct (1:1) and low is underdrive. So with all that said on a 2100 rpm governor you will be doing 56.5 mph theoretically on paper. If those are 11R24.5 then you will be a few mph faster at 2100 RPM. FYI..... 5 hours ago, Will100 said: The spec sheet says it should be a TRDL-725 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567853 Share on other sites More sharing options...
67RModel Posted 10 hours ago Share Posted 10 hours ago 4 minutes ago, Joseph Cummings said: OK. then 44mph on a 2100 rpm governor with 11R22.5 rubber. 🤣. I have to think that was slow even back when that truck was in its heyday. I forget the final O.D. ratio in the quadbox but my B81 had 9.00:1 rears and was good for about 42mph on 1200-24 tires maxed out on the governor but it was set up to move major weight. Unless going real local it wasn't even practical to bobtail to shows. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75069-new-b67st-not-sure-where-to-start/#findComment-567858 Share on other sites More sharing options...
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