Craig N

Oh man, I didn’t know anything about this. So, the heads basically stop the sleeves from coming out the top when they’re bolted on? How would I clamp the sleeves on properly? I’m assuming vice grips isn’t it haha.

Breather tube coming off the valve covers. Nothing at the end of the tube, just open. The air hose to the intake broke off at the firewall so they got in there too. I’m gonna yank the heads and clean them up really well in the parts washer. I’ve got the cylinders soaking in marvel mystery oil at the moment. I’ll see what shape the cylinder walls are in once I get the heads off. I’ll clean everything up real good and try freeing up the motor without the heads on. Glad I didn’t get it to spin over and cause any damage. Hoping she just needs a good cleaning and she’ll be ok

Looks like I don’t have the full flow/bypass oil filter so that big pain in the ass luberfiner has to go back on I guess.

Well, I’ll do my best to not put any bananas in the gear box, but no promises. Man, lots of mouse poop in the intake ports. That intake surprised me being made of aluminum too. Was waiting for a 200 pound intake but was pleasantly surprised lol. Wonder how far the mice got, I can’t imagine they got passed any valves. Could’ve pissed in there a bunch though I guess. Got cut short but I’ll try and get the water manifolds and exhaust manifolds off Monday. I won’t be able to get there tomorrow

Nope, no sealer on head gaskets. I’ll get the studs out, clean them up and go from there. I’m gonna go to the garage in a while and start tearing the manifolds off. Might get the heads off today but if not, tomorrows another day. Gotta drain all the fluids first I guess. Got that luberfiner in the way I have to get off too.

I’ll get a look at the studs when I get the heads off, but underneath the valve covers was still nice and oily (mice and all) and there isn’t any rust on the nuts on the outside of the valve covers, so here’s to hoping!

Oh, that’s a good question. I doubt I can get bolts and studs from ARP for a 673 Mack lol

Yep. Rather be safe than sorry. I must’ve vacuumed 5-6 little mice out of the rocker area. There’s mouse poop in the air intake. There’s bound to be dried mice hanging out in the cylinders. Acorns. Who knows.

If I have time tomorrow I’ll start tearing the intake, exhaust and coolant manifolds off.

Well if this ain’t a sight for sore eyes!!! A little tension with the puller and prying them with the heel bars from the valve cover side did it. There’s mouse evidence in the air intake as well. I think it’d be foolish on my part to not take the heads off at this point.

Well, there was a mouse house in the front valve cover all in the rockers. Haven’t taken rear off yet. Bunch of dead mice too.

Would you guys recommend using this injector puller to try and break these stuck ones free? I could use this and pull with the heel bars at the same time. I just worry about the threads that the puller threads into. About 3/4” of threads though. What do you guys think? How much should I “crank” the puller down? I’m not going to put an impact on or anything

Oh, that must’ve been a great feeling hearing that thing sing after you got it all back together!!

It’s like any other project, whether it’s a house project, work project, car/truck/bike/boat, it’s not usually going to go as planned haha. Usually takes 3x the amount of time that you plan it to take, or more. I guess I’ll know if this motor will ever run again once I tear the heads off and see what I’ve got to work with.

I just found a 673/711 manual from 1966 on eBay! I’ve been looking and haven’t found anything until now. Snatched it up!! $50 for a Mack service manual is a good deal in my book

Oh good. I don’t mind tearing it down as long as I can get it back together with the right gaskets and what not. I’ve made gaskets out of thin cardboard and gasket material but a gasket kit sure is easier haha. I wish I had a service manual. Those are hard to find for sure. I think the Mack museum used to send them on a pdf but last I checked the website was kind of on hold fe Covid or whatever. I’ll go check again

Thanks for reminding me about having patience. I know better for sure. I just really didn’t want to get into the motor but it is what it is and I’ll do it. Worried that they don’t make parts for it anymore, but if I break something because I’m being hasty I’m gonna screw myself. That said, is the 673 considered an “E6”? Does this gasket set look like it’s for the 673? Looks as if the head gaskets match up but just wondering about the rest of the manifolds etc

You aren’t sounding foolish to me. Sounds like you took your time and had some patience haha. Yeah, I might end up with the heads off this one I guess. Was trying to avoid it but I guess all in all it’ll be less work to pull the heads and get it free than it will be to replace the motor. I’m just anxious to get it running and was hoping it was going to be easier than it has lol. I suppose I’d be better off taking my time, pulling the heads and trying to break it free that way rather than yanking it around the yard with a loader and chain and possibly wrecking rings that I can’t replace. I’ll get those injectors out with the heads off at least haha

Also, looks like the line that goes to “in” on that fuel filter comes from the crank case behind the injection pump near the air compressor? Am I looking at that right?

Well, I didn’t get anywhere with it tonight after work. I pried on those injectors with pipe extensions on the heel bars with all my might and didn’t get anywhere. I can’t believe how stuck those two are. All the others came out fairly easy. I tried putting a 1” breaker bar on the 1 5/8” crank bolt and didn’t get anywhere with that either. I jacked up the rear end, put it in high gear and tried spinning the wheels but it just made the rear end slip. I think I may have to keep one set of wheels on the ground if I want to get anywhere with that? I’ll try dropping the driveshaft and putting a porta-power on the yoke off the transmission, as mrsmackpaul suggested, if I can’t get anywhere with wheel spinning. Weasel piss has in been in the cylinders for a day. I’ll let it sit for a few more days and see where it gets me. I guess if all else fails I’ll try tow starting it in a week after the cylinders have really soaked. Might have to pull the heads. At that point I might think about putting a 237 in. We’ll see what happens. Thanks for all the help and suggestions. I’m just getting started, I’ll give it hell trying to get this thing free. On another note, anyone seen a fuel filter like this? It’s not really mounted to anything, just kind of sitting on the crank case:

Could be any number of things. Clutch seems to work properly as seen from viewing through the inspection hole in the bell, so I’m assuming the clutch and trans can be ruled out. I’m going with the easiest route before I pull the heads. The injectors, although two are being stubborn, are easier to remove than the heads. If I can’t turn the motor after letting the cylinders soak for a while I’ll go from there. I’ve unstuck some other motors (not Mack, not diesel) with oil soaking and a breaker bar with no I’ll effects, so here’s hoping I don’t snap any rings and ruin the cylinders/sleeves haha. 237 going in if that happens I guess lol

I’ll leave the injectors alone then. I’ll keep away from the slide hammer and heat too.

I’ve got weasel piss down the other 4 injector holes, I put mostly mystery oil and some PB blaster in there. I’ll have at it today and see how far I get

Ok, I’m gonna keep going with the prying, I’ll leave the studs alone and follow instructions ha