1962 B-673ST Mack working restoration:

[1693TA]

Hello, this thread will concern my old Mack tractor which is to go back to work in near it's original configuration. I am the third owner of this tractor with the prior owner making purchase in 1972 from JM Steel Supplies out of Chicago. It ran a dedicated route between Chicago, IL and St. Louis MO for many years hauling a flat with headboard and loads of steel both ways. The tires installed when I brought it back to my shop were even branded JMS in the sidewalls. All 10 were caps, very old and unsuitable for any type of on road usage. The engine is a Mack ENDT-673B with a Mack Duplex TRD-720 overdriven transmission. The rears are Mack 34K tandems with 5.77 ratio. I've not driven the truck but am told by the prior owner it would run about 65mph wide open. The engine runs very well but I have no history on it at all.

Now for some history on how it came to me and it's a bit "windy":

I was in the auto body collision repair business for a lot of years along with working a full time job to fund college educations for both my kids. Back in mid August 2009 a gent whom I'd never seen before stopped by the shop as I was repairing a lawnmower deck for work and asked for me. Upon our meeting he stated he had an older Mack truck he would like me to have knowing I was a collector of them. I of course asked what he had to ascertain interest to which he stated that he did not know. Keep in mind this is an older gent whom is obviously a farmer by appearance, (wearing overalls) and unlaced boots which is common in the cattle lots around this area. I have an "A" model Mack, several "B" series, and several "R" series in the shop so asked what the cab of his looked like. He immediately responded with "like that" pointing to a "B-61" cab I have on a stand. He also stated the back of the cab was "caved in" to which I asked if the back window followed the contour to which the answer was "yes". I also asked if the cab had a "doghouse" and "yes" was the answer to this question. I asked if it were a "B-67" series and that rang a bell. I was also told the engine had a "blower", was a "full screw" and plenty of power for what it was. Ahh, was my realization as he most likely had a B-67ST or variant of the series.

As it turns out he had owned and ran the truck for many years in both his farming and bulldozing operation(s). The truck was replaced in 1998 when the Alcoa aluminum manufacturing plant closed up and auctioned their 1988 R-690 tractor. This B-673ST still has the IL state inspection sticker in the window that expired in 1999 as it never moved once the R model went into service. He showed up to the shop to ask me about acquiring it after purchasing a new planter and this truck was in the way where it was to reside. When asked what he needed for the truck, (unseen at this time) his answer was "Whatever you think it's worth" and man do I hate answers like that..... Figuring without seeing it I'd offer scrap price at the time we arranged a time to meet to where I could view the truck.

Now being through that, the truck was kept inside a barn and as was all of his equipment. Turns out he has hogs, cattle, and farms several hundred acres for both feed and sales. Pretty busy guy really. I later find out he is a very good dozer operator too. Anyway, I meet him up at his barn and this is the first sight I see of the truck:

Starting a walkaround:



Former owner is on the left of photo:


Overall pretty good shape for it's age in this area. Birdshit is complementary I'm told. The engine is not stuck, the oil and coolant are full, batteries are still connected, and all 10 tires have air in them. He has not even opened a door on the cab for over 10 years but the new planter needs the space this truck occupies. Grasping a tire, and with great effort I am able to shift the weight of the truck so it will roll easily. Now with my interest peaked I again ask what he has to have for it to which his reply literally "stunned" me which doesn't happen very often. He said, "Nuthin, I want you to get it out of here so I got someplace to park my planter!". I'm obviously living right as I had absolutely no inkling that was coming as he handed me the title from his bib pocket.

I'll continue if the interest is still there and the audience hasn't fallen asleep.....

Thanks,

 

[mowingman]

Signing in. Want to hear more of this story.

 

[1693TA]

To continue:

I arranged to borrow a gooseneck trailer with a winch to extract this tractor as there was plenty of room to get around. It pulled up onto the trailer without fanfare and I got it back to the shop which was about 16 miles distant. In between the time I'd been given the title and actually picking it up was about two weeks and I had received the antique license plates back in almost record time by this state. "62 Mack" is it's number but I call the truck "Snuf" for "Short Nosed Ugly @ucker" as the engine is actually nine inches into the cab and offset to the right about 15 degrees for enough room to drive it. The passenger side is quite cramped. The truck is beautiful to me however, but the name is catchy.

Nothing much left of the vinyl and burlap interior citing age and probably critters but even the "eyeball" interior lamps are there:



Upon opening the rt. hood panel, here is the "blower" that was referenced:



Upon closer examination you can see on the side of the turbine housing where it has been rubbing on the fender filler panel. There are no rubber insulators left in the rt. side rear engine mounts allowing these items to contact each other. The installation is tight but there should be about 1/2" clearance at a minimum. With the filler panel removed:



Arrival at the shop under the cover of darkness:



I unloaded the truck to return the trailer and will show the first outside photos in a follow up as can only attach four photos per post.

Thanks,

 

[Truck Shop]

Oh there is lots of interest, and i'm not asleep til 7:45 p.m. PT. This will be a good thread.

 

[1693TA]

Continued:

It rained a bit in the overnight hours but here is the truck seeing it's first light of day in just over 10 years:





I was tempted to retain the "custom" full rear fenders, but elected not to.....

Upon dragging the truck into the shop and after installing two new Group 31 top post batteries to replace the four six volt cells, the engine wound around easily. I let it spin for about 45 seconds with the fuel cutoff pulled to ensure it would have a light oil coating on all surfaces before attempting to start the engine. I then started to work the manual fuel pump primer to which I could get no resistance. Evaluating further I discovered underneath the fuel crossover tube, (hose actually) had rotted in two and there was no fuel in either tank. After chipping crud from around the shutoff valves of both tanks, they closed and I dumped a fresh five gallons of offroad diesel into the right fuel tank as that is where the pickup is located. Now working the hand primer I got some resistance but immediately severed a discharge hose leading to the fuel pump gallery. Off into the storeroom I go and replaced this piece of hose with another section to use as a test. With this installed fuel pressure came right up and the engine readily fired off taking a few moments to settle down to a smooth idle.

First smoke:



Turns out the truck really runs very well and no blue smoke at all. Plenty of black as you get into the throttle but old Mack engines tended to do that..... The engine readily fires very easily now with oil flowing to the governor as it has the "Woodward" throttle installed and require engine oil pressure to operate correctly. Once it warms just a bit the idle is very smooth, acceleration is crisp, and return to steady idle is very satisfactory.

After verifying the clutch disc was not frozen to the flywheel I found the transmission easily slips into and out of all gears. Also found the foot valve was very much stuck and when forced down, it wasn't coming back up!! Grabbing the plunger with a pair of "Channelock" pliers I was able to get it freed up so elected to go for a "jaunt" around the fields surrounding my shop. Didn't take but just a couple of feet to discover the brakes were not all working as upon light service brake application the truck "darted" to the right and jerked the steering wheel loose from my immediate grasp. I'll follow up on this a bit later. Now knowing the brakes were questionable I took it easy until getting onto a field service road then wound it up a bit. The truck accelerates well, shift nice and is overall pretty good. It was pretty easy to tell the truck needed king pins by the transfer of motion up the steering column but I ran around about 1/2 hour in the field bouncing and smiling all the way.

Getting back to the shop and exiting the truck to open the overhead door I could smell antifreeze which was hot. Thinking I had a leak I noticed the smell and steam was exiting the engine through the crankcase draft tube. I quickly backed into the building and parked the truck in the stall where it is now. Removing the oil cooler and disassembling the same I found the "O" rings had shrunk from setting and were bypassing the coolant into the oil. I ordered a sealing kit which was still supported by Mack and rebuilt the cartridge. The crankcase oil level was now about 1.25 gallons over full where it was at the full mark prior to starting out. Knowing the truck is not arabic and should not be making oil, I figured the oil cooler had failed as have seen this many times in the past. I did drain, install new filters, and cleaned the sump screen installing fresh SAE30 oil, (as per prior owner) and then allowed it to run almost two hours in the shop without any additional cooler leakage. I then washed the cooling system twice with "Cascade" dishwasher soap and recharged with a fresh 50/50 mix of antifreeze.

I'll update with some on the teardown as time goes on.

Thanks,

 

[Truck Shop]

That sounded promising from the stand point of the engine runs well without IP problems and the gearbox is working well. The sheet metal on that 67 looks good.

 

[Labparamour]

Nice acquisition!!
I’ll enjoy following this thread.

Darryl

 

[1693TA]

Now I'm going to tell you why the truck was "gifted" to me at no cost. As mentioned I was in the auto body business a lot of years. I also ran road service calls and had rollback trucks. One hot afternoon I crested a hill and seen a young lady with a Dodge Caravan on the side of the road with the hood up. As I went around her I noticed two car seats with little ones strapped in and knowing it was mid 90's in temperature and a hood up usually meant a non runner, I pulled over to investigate. It turns out the engine ran fine but she did not know the spare tire was underneath the van between the seats, nor how to extract it! The hood was up to allow the engine to stay cool till she could get help. I, (feeling her plight) changed the tire and sent her on her merry way without charge. Sometime later and just before Christmas I had a Dodge Charger come in after a deer hit. The gent had a $1000.00 deductible on his insurance coverage and although I usually didn't do this, I allowed him to make five $200.00 payments to the shop over 10 months. Never really thought too much of it but that old "Bah, Humbug" attitude must have subsided for a bit in a moment of deliriousness..... Anyway both of these were the prior owner's kids. Unbeknownst to me I'll add, but I was certainly remembered for many years through Christmas cards and a couple other small jobs on top of the truck gift.

 

[Cody danos]

Dang. Really enjoying this thread. I’d love to see your other rigs as well.

 

[1693TA]

Continuing:

Deciding I really didn't like the brakes being as they were I decided to get after them to make it right. Boy was I in for a surprise when I started breaking the hubs apart! Only three of the six brakes installed worked at all. The rt. front, the left front drive axle end, and the rt. rear rear drive axle brakes were operational. The rest either had blown air chambers, or were frozen solid. Here are a few shots of the rt. front of the forward drive axle end:






The left front wheel had a type 16 service chamber which the shell was rusted and had pieces missing from it. It did not stroke with shop air applied. The left rear rear had a Wagner Power Amplifier chamber and was frozen solid as was the wheel end shown. The other two ends were Bendix Rotochambers and one of those on the right side of the rear rear was near frozen solid but did break loose. As you can see from the photos the one wheel seal was leaking terrible. I think the "Good Ole Boy" rules applied in this truck getting through inspection myself.

After stripping off all the defective brake components, the drums all cleaned up with plenty of meat remaining. I then had the original cast aluminum brake shoes relined complete along with all new wheel end hardware. They did a nice job with that but it is expensive to have done any more. The original slack adjusters are good and usable but the cams themselves were beyond shot. They were almost an 1/8" down in the bearing surfaces. Unable to find replacements, I had my uncle anneal, build up, turn, reharden, then regrind them to the 1.50" dimension needed. They look new although there is minute wear to the splines. The slacks still fit tight so should be alright for use. I wanted to go with auto slacks but the centerline pivot to the rears is 7.0" and I can't find auto slacks with that much available. The fronts are 5.50" pivot so they are going there. The brake spiders are too large to allow mounting larger brake chambers so going to install new type 20 service chambers on the drives, and stay with type 16 on the steer. If someone could show me where it is legal to make spacers to relocate the brake chambers and use offset arms I could squeeze in type 24/24 spring brake chambers or possibly even 30/30 types but I'm not willing to find out they're not legal on the side of the road by a DOT cop. I have pulled the cam bushings from the spiders and do have new but they've not been pressed in yet. I'm needing to paint strip and refinish the spiders yet.

More about the brake hardware in the next installment.

Thanks,
I did install new king pins after finding a vendor in NOS parts for the series axle I have which is not that common any longer. They were the ream to fit but I still have my expansion reamers and had a friend make tapered pilots to keep things centered. All front end parts are tight now.

 

[1693TA]

Continuing:

Probably going to be the last installment for the evening but here are some shots of the brake hardware:

Sandblasted clean:


Same parts painted:


What is not shown is the spraying of the bare ferrous parts with a 20% solution of hydrochloric acid to remove the flash rusting seen in the first photo, then the high build epoxy primer/sealer followed by the 2K custom tinted Mack red polyurethane enamel. This stuff will take the heat of brake drums and not lose it's sheen. I could not get all the grease and such removed from the rear spokes and drums so separated them and they are currently at the blaster to be stripped clean. Getting anxious to get this part wrapped.

These are the rim spacers. I went with Ford Argent Silver for these. They too were blasted clean, (although new) to get the same treatment:




Hope the posts so far have been entertaining at least.

Thanks,

 

[funwithfuel]

I'm surprised she wasn't fitted with wedges. Got real lucky with S-cam foundations.

 

[Junkyard]

That’s an awesome story and a great truck! Gotta love the B Model. I’ve had a few and worked on quite a few. I don’t believe in much than I cannot see but I am a FIRM believer in karma. If your story isn’t proof positive.... I don’t know what is!

 

[1693TA]

I have one truck, (1974 RL797LST) with wedge brakes and they work well. They have been taken care of however.

 

[1693TA]

I'm surprised she wasn't fitted with wedges. Got real lucky with S-cam foundations.

I have a single truck with wedge brakes. It is a 1974 RL797LST. They work well but that one is very torn apart for a frame up restoration. It is serial number 19001 which I think is the first truck built for the 1974 model year but not certain. It is all original with engine, trans, and rears.


Going to replace the cab on this one as after removing the rust found out this one was unbelievable rusty. It worked the Long Beach Naval Shipyard in CA for a lot of years and I guess the salt air really ate it up. I got it on a trade deal from a guy in MN whom bought it out there and brought it back but never touched it. The Mack V8 engine runs very well.

 

[Junkyard]

I have a single truck with wedge brakes. It is a 1974 RL797LST. They work well but that one is very torn apart for a frame up restoration. It is serial number 19001 which I think is the first truck built for the 1974 model year but not certain. It is all original with engine, trans, and rears.
View attachment 203901

Going to replace the cab on this one as after removing the rust found out this one was unbelievable rusty. It worked the Long Beach Naval Shipyard in CA for a lot of years and I guess the salt air really ate it up. I got it on a trade deal from a guy in MN whom bought it out there and brought it back but never touched it. The Mack V8 engine runs very well.

Love me an E9 V8. They sound awesome and look bada$$ sitting low in the frame rails!

 

[1693TA]

Found these of the front brakes backing plates and chamber mounts. Same paint treatment:





The parts are sprayed slick enough they should be fairly easy to keep clean.

Found one of my license plate:

 

[RZucker]

Love me an E9 V8. They sound awesome and look bada$$ sitting low in the frame rails!

Drove an early Superliner for a while with the 450HP version. I thought it sounded like an over jetted gasser. But then I like 2 stroke Detroits. Love a bit of 12V71 music.
Found that old Mack sitting by a cornfield a couple weeks back near my house... Still working hard after all these years.

 

[1693TA]

Love me an E9 V8. They sound awesome and look bada$$ sitting low in the frame rails!

I don't have any E9 series engines. I do have three ENDT866 engines and one ENDT865 engine which belong in trucks I have.

This is my "Water Wagon" and it has an ENDT866 engine:



This is an R795S series. It currently has an ENDT865 that has been turned up but I purchased this truck to install a 12V-71T Detroit Diesel into. One of these days I'll get around to it:

 

[Truck Shop]

A Hah Your Rob from over at Big Mack Truck Forums, the radar engineer gave you away, and the long winded descriptions.