mattb73lt

That really looks great. What a wonderful job!!

There you go! One thing at a time, one problem at a time. Keep at it!!

No, the entire rear or stretched area is from the donor truck, a Ford Louisville. I cut the donor just behind the cab. I was able to slide the Ford frame directly over the Mack. I believe Freighttrain did a similar stretch to his B61. We had a separate conversation long ago on another thread about it. This was the area I used.

The aluminum really pops with the stuff we were using. Great contrast between the paint and brightwork.

I'm thinking about it. I might just do a resonator. Something to soften it just a little. The Jake brake is just obnoxious when it goes off. It does keep idiots away, though!!

Oh, and the split manifold was two pieces with two separate pipes. Three cylinders into each manifold. Ellis was the maker. I’ve seen homemade split manifolds, and only a couple of Ellis ones. Those are probably the rarest to find.

This day took almost 25 years to make happen. Out chasing parts for the B42 and stopping by to see friends and their garages. One had me pull in to his air conditioned shop to show me the different aluminum polishes he uses and do a few test spots to see what worked best. The big dog didn't even mark new territory or leave a calling card on his floor. 200+ miles and counting!! There's a little video he took of me leaving below this picture. IMG_1003.mov

No worries, we all have to start somewhere. The only way to find things out is to ask questions. The answer mostly had to do with Cummins engines and the NH series, 220, 250(although it's a NHC250 and 855 CI), 275 , etc. Most common exhaust manifold was the center dump, it was a three piece manifold and dumped straight down in the center section. The backdrop ran almost straight back to the rear of the engine with slight down turn, hence "Backdrop". There were two types of back drop, one with an internal baffle or divider. That one was meant for the NH/743 CI series. Then one without the baffle, meant for the NHC/855 CI series. The one with the baffle makes a particular exhaust note due to the fact the baffle prevents the exhaust gasses of the first three cylinders from mixing with the back three cylinders until they exit the manifold, giving the exhaust that particular "bark". There were many manifold made for both engines depending on its application and installation.

Up to 150 miles, as of today. Trying to put 500 miles on it and then change the oil and filter on the engine. It really is running well. With no body on it, it just floats along at 70 turning about 1650 on the flats. Lots of thumbs up as I’ve been using I-91 from Meriden to North Haven for my runs. Mechaholic, if you want to go for a ride, give me a message and I’ll have you come over? I had a very close call in the B42, today, when I was picking up the hydraulic cylinders in Danbury. On the way back on I-84, I had a rear service brake line fitting come loose and separate. I didn’t know it until I needed to stop and had almost no brakes. I heard the rush of air and had the pressure gage dropping until the maxi-brakes started to come on. I was able to stop, but it was close, in building afternoon traffic. Tonight, I’ll replace my underwear. Tomorrow, I’ll replace all four service flex lines to the brake cans. Damn!

BTW, I’m not trying to hijack nam vet’s thread, just trying to give him some visuals to help with the issue. TY.

Push type. I hadn’t put the cross shaft and fork in yet when I took that.

No worries, post away. That transmission and frame was a dirty mess when I found it. 350K + miles and left in a field. It wasn’t a magic wand that made it look like that.

Triplex. TRTL-720 to be exact. Double overdrive, double disc clutch and a clutch brake.

There are variations to what Mack did. Most frame and transmission mounts were cast. Gas and diesel mounts are different as we discussed. Just for general info, there is a difference in single and double clutch arrangements, too. Double disc clutch’s require a 1” deeper bell housing on the transmission side, moving the transmission back 1”. Mack used an offset welded mount made out of 1/2” plate. They’re roughly made and not cast. My B73 has these. If you look at these pictures you can see the off set. Most mounts bolt directly to the frames and transmissions.

I've seen cast spacers and washer stacks underneath transmission and motor mounts on trucks I've parted out. If the alignment is good the bolts should go right through the mounts and bolt up, you shouldn't have to force them and they shouldn't have any preload on them. Pictures of what you're dealing with would be really helpful to help us see what's going on to help you?

The sheet metal is all together. I need to make a few adjustments and fill a few bolt holes, but it's looking good. Very happy it’s back together!

It sucks. The rear has no give and bounces pretty good over bigger bumps on the highway. Local roads are easier as the speeds are a lot less. I think the gearing is spot on. With the 4.62 rear, double over Triplex and 24.5 rubber it just floats at about 1650 RPM at 70 MPH. That's barely half throttle. If I come on a hill/grade, it's a quick downshift to 4th Hi-split and you're over it. I love the sound of the exhaust, but down the road I'm probably going to put a muffler on it.

No, i think it was just messing with me!! Hasn't done it since. I put another 50+ miles on it today, so I'm up to 210 miles total and 110 on the new motor. Admittedly, I'm still a little gun shy about running it after the first time it blew up. I'm alert to every smell, noise and vibration, but so far all is OK. I'll make a video soon of a road test.

The basic engine is the same. The bell housing is the difference. The tilt shouldn't effect anything as it was designed to be that way. As long as there's no interference with the firewall or other areas, I can't see any issues. To get it vertical, the best way to do that would be to swap the engine bell housing. The B67 series had the fire wall cut out and a removable "doghouse" inside the cab for access to the rear of the engine, as the cab was moved forward on the frame and the front sheet metal was shortened. As for the color, earlier engines were a blue-grey tint, similar to a Detroit Diesel. I believe the Maxidyne was the engine that started the gold paint, from 237 HP and up.

The back drop dumps out the rear, versus a center dump. Additionally, it has an internal baffle that prevents the gasses from mixing until they leave the manifold, giving it a particular and distinct bark. A split manifold is actually two separate manifolds.

As for pin striping I do have a plan. Thick gold or maybe Cummins Old Gold for a main stripe and on the inside of that a thin Mack or Emerald green stripe. I'll probably put my name on the door, kinda like the other truck.

Yes, rear flaps. The deck has a head board on it. You can see it peaking up over the back of the green truck. it's about 67" high.

Test runs!!! Headed out about midday after the rain stopped. First one I went 25 miles, circling the house on local roads. I stopped often to check driveline temps, leaks and if anything was coming loose. Went back to the house to shut it down and check everything. Lost a little antifreeze though the cap, but it was topped up a little too high. Went out again, this time trying some highway(bravely). Was on another short circuit when I saw I had about 90 psi air pressure and slowly dropping. Was making a beeline for the house and got down to a little less that 70 psi and was crapping myself, then it started to build again. Went up to 120 and cut off normally. Got it back to the house and bled it down and the compressor cut in at 90 and cycled back to 120. Did that several times and it operates as usual. I think it was just trying to get me to leave skid marks in my drawers!! It runs great, though!! 60+ psi oil pressure running hot and 25 at a hot idle. Traffic was getting heavy, so I’ll go out another day for more miles.

So your saying it's leaning to the passenger side? A short nose B67 had the engine tilted to the passenger side by, I think, 14 degrees. This was done to provide clearance for the driver's feet, steering box, etc. If you have a standard cab the engine should be vertical. The frame should be pre-drilled or gas or diesel engine mounts and as you stated, they are different. I've done this swap to a B42 and have a 237 in mine. If the previous owner did the swap it could be possible they used a B67 engine. To tilt the engine Mack drilled the bolt pattern offset on the engine bell housing to get the tilt needed for that application. Pictures of what you have would be helpful to determine what's going on and to more clearly see your issue?

That is really coming out nicely!! It looks factory new. Everything is clean, crisp and sharp. It takes so much effort to make that happen. Beautiful job!!