SuperB

I'm rebuilding the normally aspirated 711 engine in my B61, and have found some concerning stuff. The rim around the bowl on all 6 pistons have small cracks in them, and the tops of several pistons are glazed. It looks to me that they've gotten really hot at some point. The engine is original and it's just a hobby truck now. The engine ran fairly well, but had some issues I wanted to fix. It has had one head, one connecting rod, and 2 pistons replaced at some point in the past, and the engine looks like it's been together for a long time since the last rebuild. I checked the pump initial timing before disassembly, and it was 29 deg (I think 28 is the original spec). I checked the timing and duration (full throttle) for each cylinder in the pump, and they all looked very good to me. This engine has the syncrovance. Oil pressure was always very good, and crank end play is good, so I'm not taking the crank out. I will be putting in new pistons, rings, rod bearings, and heads. Liners are good. I have not had the injectors tested yet, but I will be getting that done also. Does anyone have any thoughts on the issues with the pistons that were in it? I've heard that these engines had high cylinder temperatures when they were new that caused head and valve problems, but I don't know if those issues would be anything I would have to worry about just playing around taking it to shows. Oh, and it has the original oil bath air cleaner on it. I plan on putting a pyrometer on it just to keep an eye on things. Maybe what I've found is no big deal and was common for these things back in the day from hard use (this truck was used to pull a water tanker I believe), but if the timing needs to be changed or something, I'd appreciate any guidance or advice you guys can give me. Thanks in advance for any help!

I was able to find what I needed. Thanks

I'm in need of a rear main seal retainer for an E6 engine, the style with the rubber lip seal. Thanks in advance for any help.

Hello, I'm looking for the panel that bolts on the front of the flywheel cover (bell housing) on a B model with a 711 or 673 engine. It's about 12" long and covers the large bell housing opening near the rear of the engine oil pan. It attaches with two 3/8" bolts. Thanks in advance for any help.

Thanks guys. I'm still not quite sure what applies to my 711 though. Here's a table for 673's in my Operation and Maintenance manual.... Here's a table in the back of that same manual for 673P's specifically. It seems like there are different numbers for each pump on each engine. It's unbelievable how difficult it is to find anything specific to the mid 60's END711. My pump number has a P8 suffix, but I can't even find a 673 spec for a "P8" pump. Maybe the Mack Museum like was suggested earlier? It looks like they stopped giving this info in the Mack repair manuals, like Steve said above.

Thanks JoJo, the engine and pump info is in my first post, except that it's in a B61. Also, it's an ENDL engine, if that helps. Hopefully it'll be in your books. None of the TS442 repair manuals I have list it, but I don't have the earliest edition.

Thanks for the replies. We must have the same O&M manual, because those 673P specs are the closest ones I can find too. I didn't think that the museum might be able to help, maybe I'll reach out to them.

Would anyone happen to have the rack setting specs for the injection pump on my truck? None of the manuals I have list mine. 1965 711 engine American Bosch APE6BB-90Q-5069B8 Mack 313GC4135AP8 Thanks for any help

Yeah, that's what I was afraid of. I'll plan on having to take them out in pieces. Thanks for the help BTW, it's an END711

I have several leaking threaded block plugs (freeze plugs) that I'd like to replace the o-rings on. Just wondering how big of a headache it typically is to get them out? Are the block threads usually ok? I think I have the right 1/2" drive socket for them, but when I tried to remove one out of a head it won't be re-using, it wouldn't budge. I'm assuming they're right-hand threads. Hopefully I won't have to cut them out or something. Any words of wisdom would be greatly appreciated.

I think what you're looking for is for sale on eBay now. It looks like the one on my 711. Just search Mack B Model Oil Filter Neck 673/711

Thanks for your reply. The ones you referred to are the shorter and more common ones, 616GC116. I'm looking for 616GC156 which are about 1/2" longer. If you have any suggestions on where I could find them, I'd really appreciate it.

I'm in need of a set of 12 fuel injector studs for a 711 engine, the part number is 616GC156. These are longer than the more common ones, I think these are about 2.75" long. They have a longer wrench area than the other type. I'd be interested in new or good used. Thanks for any help.

Thanks for posting the chart. To tell you the truth, I didn't even know if the jacks that Mack provided were hydraulic or mechanical. So it looks like a B61 would have gotten an 8 or 12 ton. The build sheet lists the lug wrenches that came with the truck too, but I can't even find a picture anywhere of what those things looked like.

I was just wondering what style & brand the jacks were that came with the B model trucks? Assuming they originally came with one. Would anyone happen to know?

This reminded me of one day (at least 15 yrs ago) when I was coming home from work through Boyertown, PA. I came around a bend on the main street, and there was a truck that I think was delivering coal to one of the old row houses in town. It was a late 30's or early 40's vintage truck sitting across both lanes, and the truck bed was raised quite a ways up in the air and had a long trough that went down to I guess the basement window. I assume he was delivering coal (maybe it was wood chips?), but it was pretty cool to see that old truck still getting things done. It was probably a pretty common sight back in the day. I don't know why I didn't take a picture, probably just so surprised to see it sitting there.

Thanks for the reply. I've found a partial kit that should work and will help, but I haven't found the top cover gaskets yet. Maybe they're not available anymore.

Does anyone happen to have any suggestions on where I might try as far as locating a gasket set for a TRD-72 series duplex transmission? Watt's doesn't have access to them anymore, and I've tried a couple of the rebuilding companies and online searches with no luck. Any help would be greatly appreciated. Thanks

It's so nice to hop in the old Mack and go for a ride now, and so many people enjoy seeing it. That makes it even better. I can't imagine what it was like doing it for 8 hrs (or more) in the blazing heat or freezing cold. And back then, there was nobody giving you a thumbs-up, they were probably all using another finger as you tried to climb a hill all loaded up, LOL. Seeing the footage of the guys driving the trucks when they were building the Hoover dam is pretty incredible. I wish there were more videos showing the old truck assembly lines and manufacturing plants.

I liked when he said "nobody drives an old truck just for fun!" I guess he's at least partially right, it's not ALWAYS fun......

For us newbies, what's meant by the BCR conversion? What did it consist of?

Thanks for that Terry. Hopefully I'll be able to find this thing. I assume it was used on all trucks with 2 rear axles, back in that time period. Just in case my description wasn't written as clearly as it should have been, this part mounts to the driver's side frame rail and has three threaded connections. The main air line from the foot valve, the air line to the front rear axle, and the air line to the rear rear axle.

I'm looking for a Bendix 3-port air brake tee or manifold for the rear brake air lines on a dual axle truck. I think it was used on many makes and years, mine is a B model. It has the Bendix number T-210768 on it. It's just a small aluminum block with one 3/8' NPT and two 1/4" NPT threaded ports on it. It splits the main air brake line into the two air lines for the axles. Please message me if you can help. Thanks in advance

I'm in need of some parts for a Bostrom Viking T-bar seat. I would need the adjusting tracks and any necessary brackets for a B model installation. The truck has the standard original driver's seat installed now. Any help with getting these parts rounded up would be greatly appreciated. Thanks in advance.

They're polished aluminum wheels, old Alcoa wheels. I was finally able to find studs that are the right length for them. The BWP studs seem to be the longest, because they don't have the really large chamfer on the lug nut end (which makes the thread length a little too short) that some of the other brand studs do. So it looks like I'm good now. Thanks for the help. I was able to get new window kits for the vintage Stemco caps on the truck. The 5999 ones fit (2 3/4"), and all of the screws came out ok. I guess mine were completely painted over at some point to make it easier to see the oil level in them, but it seemed to make it harder