doubleclutchinweasel

There are a couple of Mack techs on here that continually blow me away with their knowledge on these things. They should be of great help to you.

Pictures. We love pictures!

No, the "early" box would not have been available. Not even sure about the "late" box! Just trying to figure out if a truck of that vintage could have had the OD set in the compound. I never saw one that did. But, like I said, I learn something on here every day.

http://www.macktruckrestorations.com/Page2/page2.html Matt Pfahl's site....check it out!

Awesome!

For what it's worth, I love the tall pipe on top of the canister. Lots of our R600s had that (like the one in my profile pic). Think it was pretty common on the Thermodyne engines (like my R611). They were originally oil-bath cleaners. Mine still was. Most of the ones we had back then had been converted to a replaceable paper element. It was a Mack kit they used to sell. When I had mine, I tried with no luck to find that old kit. Would have loved to have replaced mine. When we got our first Maxidyne truck, it had the short pipe on top. Little squatty thing. Not sure if that was a Maxi/Thermo difference, or if it just happened to be the right year model. Or, maybe it was a paper filter setup already. Do not remember. But, I do remember the one I spent most of my time in having the "oil bath" canister, but with the paper filter inside it. Was kind of a nice surprise the first time I pulled the bottom off of it and DIDN'T get oil all over me! I have also seen many a Mack with a plain black aftermarket canister on them. I think it's a Donaldson item. Looked something like this. Maybe you can adapt something like that.

If a straight drive transmission is an "anti-theft device" for new drivers, then a Quad would have to be like Kryptonite! Actually, a Quad should qualify for a lower insurance premium, since nobody could steal the blasted thing!

Story of my life: a day late and a dollar short!

Different years? Gas vs. diesel?

Correct. The "later" ones are the ones I was more familiar with, where the REV was in the compound box. I don't think I ever saw the "early" one in person.

Hopefully, you will find a "direct in 4th" setup, which gives you double-overdrive. Makes for a very long-legged puppy. I'll be watching this one closely! You've got me interested!

Is the shift plate still in the cab?

IF that's the original transmission and IF that's the original plate, and IF the plate is correct, and IF there was an overdrive in there, the plate would lead one to believe the overdrive was in the main box and the auxiliary was direct. Of course, I would still spin the main box to be sure. That's really the only way to tell for sure. See if the output shaft turns the same as the input in 4th or 5th. Anyway, I hope you get it sorted out. It's a real pain to give up highway speed. By the way, I have a friend who, years ago, swapped out a 9-speed Unishift for a "split 5" Fuller in a B61. He thought it was a 10-speed with overdrive, but it did not have a hi and lo range...just a lo and dir splitter on a 5-speed box. Wanted more speed. I tried to tell him his 9-speed was an overdrive box, and his Fuller was either a direct or would have roughly the same overdrive as what he had. He was convinced the Unishift was a direct. He was very unhappy after he went to all the trouble to put the Fuller in, only to find out it was a direct model...just like it said on the splitter (lo & dir)! Lost at least 5 MPH. Could have saved all that hassle just by shifting it and spinning the shafts, all while it was laying on the ground! What he ended up with was essentially the same thing as his Unishift, without the overdrive. Sorry. Kinda went off on a tangent there! That's neither here nor there. Just kind of a humorous story. Anyway, good luck getting it sorted out, and let us know what you figure out.

My RT-915 had the same problem. I usually had to flip it lo-hi several times before it would work the first time. After that, it was fine for the rest of the day. I think mine ended up being a combination of an air compressor bypassing a little oil and the "slave valve" on the transmission. Of course, the old model had been discontinued, and I had to adapt the newer model to it. Looked something like this.

Seems like I have seen the "reverse the arm" thing done before. If you can work in a cable setup, like 63BMack is talking about, I think you'll be very happy with the results. My '70 R had the cable setup on the pull clutch, and it was the easiest clutch I ever drove or adjusted. Be interested to see what you come up with.

Welcome to the Dog Pound, John. I think you'll enjoy it here.

Yeah, a TRT-7220 or TRQ-7220 should hold up fine. Learn to split all the gears, and that DD would sound great going up through the cogs! Only about 300 RPM drop if you hit all of them.

I'm kind of a Quad-freak! I grew up on the 18-speed double-overdrive Quadruplex. Have driven the 13-speed Triplex version. Same, without the LO-LO gears. Love those 2 boxes. Once you learn them, there truly is a gear for all occasions. Had 2-3 different shifting sequences, depending on the load and grade. Even developed a couple of different split-shifting styles. Again, depended on how big of a hurry you were in. To me, a Mack needs 2 sticks. The 15 RoadRanger I had in my '70 was a much more user-friendly box. But, I always felt a little bad that it didn't have the Quad in it. I hope to have another one someday.

Here was that engine... http://www.tyldenheritage.com.au/uploads/9/3/0/6/9306704/endt673c.pdf

Certain models of Triplexes and Quadruplexes (and there ARE different models...check your model number) were routinely used behind the ENDT-673C, which was rated at 250HP and 701 ft-lbs of torque. I have hauled 111,000# with that setup many, many times. So...

What kind of torque is that Detroit rated at? I see info suggesting 650-666. I think the n-plex boxes were used with engines rated up to 650 ft-lbs or so. If that's the case, it should be fine. Like with a Maxi, maybe keep the revs up...which shouldn't be an issue with the DD.

Sexy as socks on a rooster...

Here is some info about the later models, with REV on the compound stick. But, I can't find anything on the OD versions (1070). So, I don't know if they ever did one with OD AND REV both in the compound case. But, it seems possible. Again, the shift map plate would probably tell if it was a lo-hole or and OD setup. Here is the plate (off eBay) for a lo-hole model.

Here is some interesting info. Apparently, there WAS a setup with OD in the rear box. If this is the trans you have, then the OD on the compound stick can only be engaged when the main is in 5th. But, I don't know if these had REV on the compound. Doesn't sound like it. I am going to dig more into the "late" production boxes, and see what they have. Learn something new every day...

I love the look of that setup. Gotta have the Mack caps on them!