doubleclutchinweasel

Nah. Just another problem! Always reads there. Tried swapping the gage wires, thinking they had not been done when it was switched from pos to neg ground. But, it didn't work at all that way. I have a precision visual fuel level indicator under the seat!!!

Okay. Put on a new 88" PAI cable (FCC-2975-088) & a new Stewart-Warner 0.5:1 ratio tach (82689). It's nice to know how fast the old Dog is turning! It's also nice to know that, whenever I need a speedo, S-W has one that matches this tach. In fact, they have a whole series.

Yeah, I believe you are correct. It was the dual-disc that had the shims.See if you can read this...

Went through this on my R. It had a mixture of 20 (tube-type) and 22.5 (tubeless) rims on it. Some were 7.5, others were 8.0, and still others were 8.25. Took them all off, and put on 22.5 X 8.25s. Used same spacers, hence same clamps.

When all the air is bled, the shutters should spring open. If something is preventing them form working correctly, you can always temporarily block off the air to the system while they are open, and run with them open. Not ideal, but will keep you from cooking something until you can isolate the problem. Alternately, you can disable the shutters by blocking off the air, and change to a hotter thermostat. Usually, a shutter-equipped unit will have a 160-165 degree thermostat, which will be open after the truck heats up. Then, the shutters will regulate the water temp at 170-185. But, if you disable the shutters, and put in a 170-185 degree thermostat, you can accomplish essentially the same thing. But, it might take a bit longer to warm up. Remember, not all of 'em came with shutters anyway. Just a different perspective for you...

There is a procedure in the Mack manual I have regarding the initial adjustment of the pressure plate after assembly. Don't remember any of the deatils. Some of these single-disc clutches also used the "wear shims" to space the pressure plate out when new, and which could be removed to compensate when the disc worn down some. Don't know if yours used them or not. But, if it does, it would probably be a good idea to put them in there. There is also a procedure for setting the cam on the mechanical clutch linkage on the old B models, if I recall correctly. There seemed to be a couple of different settings for the cam, based on exactly which clutch was in there. Again, don't know what clutch or linkage you have. I'll try to find some of this info, take pictures of the text, and post them here. Maybe it will help...maybe not.

Friend of mine from Tennessee says that's exit 407 off I40 (Sevierville exit). That's the area my R came from.

Changed the rears out this morning. Same deal; one came apart easily, and the other one had to be cut off! New bolts on the fronts. A little anti-seize between the bolts and sleeves. Let's call it done!

...and the standard R-model way back then was 103" BBC, if you trust the Mack brochures...

I've said it before, and I'll say it again... A Mack 18-speed is supposed to have 2 sticks! Thus sayeth The Weasel...

2 down, & 2 to go... Left one literally took 10 minutes. Right one took an hour, because the sleeve in the old mount was stuck to the bolt. Had to cut the rubber off and grind the sleeve in two to get it off. After that, 10 minutes. For lack of a better plan, I re-used the same flat washer count that came out of it. Maybe I can do the rears this weekend. Think I'll replace the bolts, too. That should be easy now that they're clean. Oh, and the uppers were, indeed, 20QL250 and the lowers 20QL1144, just in case anybody else needs to do theirs. These are actually the BWP-NSI parts (MA9R & MA9O, respectively), ordered through FinditParts, and shipped directly from BWP in Missouri. Good prices, quick delivery.

Yep. The manual gives a torque spec. But I think I like your suggestion better. The book also mentions shimming the cab as needed to align it with the hood. Stuff should be here by the weekend. Hope to get a start on it at least.

I'm sure someone will correct me if I'm wrong, but I think the 864 is shorter than the 673...

I grew up riding with my Dad in B61s & R600s. So, I had plenty of room. No suspension seat, but plenty of room!

Actually, i don't think the centered cab of the R-model has any different leg room on the driver's side than the offset cab of the U-model. The R-model cab is almost straight across the front edge, with uniform leg room pretty much everywhere. But, the passenger's side of the U-model is a lot tighter, if i remember correctly, 'cause the doghouse intrudes into that area a bit. I'm sure Vinny could elaborate. Not sure about the actual difference in cab length (if any) between the U and R. I BELIEVE they did shorten the BBC just a bit, though. I'd have to check the brochures to know for sure. So, you're probably correct; if the BBC is shortened, and the doghouse intrudes into the cab as a result, the offset would help legroom on the driver's side, albeit at the expense of the passenger's side. Who knows what is true and what is legend...after the marketing department gets hold of it!

Nice to know it actually had a name...not just "lopsided m#@&$@#&$@#r"!

According to Mack, this truck should use an 88" tachometer cable. I still don't see how. But, I guess I'll measure it out again, and see if it would reach.

Okay. According to all my research, & even Mack, the cab mounts are as follows: Upper - 20QL250 Lower - 20QL1144 Radiator - 20QL231P9 There are several aftermarket versions as well (PAI, BWP-NSI, Rubber, Urethane, blah-blah-blah). Not sure if any are better than the others. Opinions or experiences? Also, is there an easy way to lift the cab and radiator enough to change the bushings without taking the thing completely apart? The Mack-given radiator mounts appear to just go in from the top, & are 1-piece. The current ones look like there are 2 pieces. Maybe the bottom flares out when they're tightened? See first picture. Think the cab mounts are due?!!! See other pictures.

Yep. Widens out just behind the batteries. Sorry,Vinny. I must be gettin' old.

I just zoomed in on the picture, and i believe you are correct. The frame appears to deepen just behind the battery boxes. Young eyes, huh? I'll try to get a closer look at it later today. that would explain the front axle...

Here are some more pics. Definitely looks like a U... Looks like a fairly serious front axle setup. Always liked the double-splined rear axles. Did not look under it to see if it was double-framed, but it wouldn't surprise me if it was.

Yeah. That's the website I was looking at. Had to change a $#@&$#@ flat tire this evening.

Sorry it wasn't better. Trying to take a pic without looking! Speed is low there, at least. Didn't get to stop in this evening for a closer look. Had an outside rear flatter'n a flitter when I left work. Had to swap one out. This one ain't on as pretty a wheel as the one I took off, though. Kinda' dirty-looking. Crap!

Do the numbers 20QL231P5 or 20QL295A mean anything to anybody? They are listed as "radiator mounts", but no specifics are given. Still searching...

I believe it actually had the "straight" frame of a U, not the "deep" frame of the DM. But, I did not stop and get up close and personal. If I can, I'll try to get a little closer to it later on. Maybe get a couple of more pics. I thought you'd appreciate the view from one old truck to another!