HK Trucking

A 12 speed behind a 3406B would be a great combination for a tractor that pulls a lowboy or a dump trailer. Since all the class 8 bellhousings, clutches, input shafts etc. are SAE standard, there would be no problem with mating the 12 speed to the Cat. .

Best of luck with your new truck. Hopefully it will be dependable and result in a lowering of your blood pressure and psychological stress level. .

Our 623 & 615 have brakes, the boss is very fussy that way about maintaining the equipment,so we don't need an excavator against the push block to keep from "overshooting" the end of the trailer. We have a guy running the scraper and a spotter (the lowboy driver) at the rear of the trailer in view of the operator to guide the operator in getting the scraper centered as it backs up over the wheels. It's still a pain in the ass. Our trailers aren't as heavy as yours, we've got a 60 ton Trail King triaxle 108" wide, a 60 ton Trail King triaxle 102" wide, and a 35 ton Trail King tandem axle 102" wide, all non ground bearing RGN's, all on air ride. The 60 ton 102" has all axles down all the time, the 108" has a liftable 3rd axle. I'm a "lightweight" compared to you guys, the heaviest piece I've moved so far is a 480 Kobelco excavator, @ 110,000 lbs. machine weight, on the 108" trailer (with the outriggers & planks of course). 615 on the 60 ton 102" wide: 623 in the shop: The 60 ton 108" wide last year right after rebuilding & repainting: .

Don't you just love backing those scrapers up over the trailer wheels? We've got a 623 and a 615 and that's a pain in the ass with our 108" wide triaxle trailer. Is that a 120" wide 4 axle trailer you're running? .

You'll be shittin' splinters.

Here's how I cook those: Put the roast in a big roasting pan, season with pepper & garlic powder, throw in some peeled onions, potatoes, carrots & peas, pour about an inch of water in, cover pan, put in oven @ 450 for 15 minutes, then cut temp back to 250 and let cook for about 6 hours. That roast is so tender it don't even need no chewin', and the onions give it a good flavor, along with the taters carrots & peas. .

As long as y'all ain't wasted all weekend then it's all good. lol. .

As Dave said, the first time you fill the rear end after a drain or repair, you fill all 3 compartments, after that when servicing you just maintain the oil level in the bottom compartment up to the bottom of the hole where the plug screws in. On the back rear, just fill the upper & lower compartments initially, then maintain the level in the bottom compartment as described previously for the front . .

Replace the motor. If that is indeed the problem. Could be a wiring or switch issue also.

Reminds me of when I lived in CT for the first 28 years of my life. We used to load up a 30 yd dump trailer as much as it would hold and run down the road that way every day (with a tandem axle tractor and tandem axle trailer - no pusher axles). 25 tons of hot mix on a 10 wheeler? No problem! Chain down a machine on a trailer? Who ever heard of such a thing? Then, sometime after I moved to WI in 1985, the truck weight regulations in CT/NY got lowered so that you couldn't do that anymore. Funny thing is, the roads in that area are in worse shape now than they were back in the days of heavy hauling. BTW John, that is one awesome DM800 you got there, brings back memories of my days in the Northeast Kingdom. .

It's a very good idea. It will save your clutch by giving a deep enough reduction to get moving off road, and will make the truck more versatile with its 5 reverse gears. Top speed on the road will remain the same, as the TRL1078 5 speed and the TRXL107 and TRXL1071 6 speed transmissions are all direct (1:1 ratio) in high gear. .

That wouldn't solve anything, you'd still have the same discrepancy in tire diameters, only in just the opposite wheel positions. You have to keep all 4 on the same side of the tandems as nearly matched as possible. That would be the best case scenario, although even a set of 8 identical drive tires could still be slightly different in diameters. .

Having or not having an air operated lock out on the power divider would have no effect one way or the other on wear of the "peanuts", except that when the air lockout is "locked" there is no wear on the peanuts because with the power divider locked there is no relative motion of the cams vs peanuts. Locking the power divider will cause torsional "wind up" of the diffs & axles when on a hard surfaced road however. Something is going on if the power divider is wearing out twice within a year. Besides the mismatched tire scenario, is there a possibility that the ratio of the front diff is slightly different than the ratio of the rear diff? I've seen that happen where someone would inadvertently install the wrong ratio when rebuilding a diff, then when the truck was operated the power divider would clunk and bang (and wear quickly) trying to compensate for the discrepancy in revs per mile of front diff vs rear diff.

Make sure you pre fill both of the fuel filters, then try to start it up and it should pick up the fuel with some sputtering and missing for a minute or 2. Don't crank excessively if it doesn't fire. To prime the system: Disconnect the fuel return line at the relief valve on the side of the injector pump. Plug the return line (leave the fitting on the relief valve "open"). Use compressed air to pressurize the fuel tank (a "blow gun" in the filler opening with a rag stuffed around it to hold the pressure in). Pressurize until fuel flows from the open fitting on the relief valve. Once this is achieved, reconnect the return line, put the fuel tank cap back on and it should fire up. Pressurizing the tank without removing and plugging the return line from the relief valve will accomplish nothing, as the pressure will also go back thru the return line and counteract the flow of fuel from the tank thru the supply line. .

Blasphemous posting. 5 post penalty!

Alrighty now, to get back on track here....... I bought a pair of Mack insulated boots several years ago and got 3 tough winters worth of use out of 'em before the sole finally separated from one of 'em No complaints about that pair, they were comfortable and my feet never got cold even working outside in subzero temps. It sounds like maybe the Mack boots are now being produced by a third world sweatshop based on what Thad has stated. .

Mismatched tire diameters on one drive axle vs the other drive axle? Contrary to how it's done with "generic" trucks where you would keep tires matched across each drive axle, on a Mack with the cam & wedge power divider you keep all the larger tires on one side of the tandems and all the smaller ones on the other side of the tandems, so as not to cause a great discrepancy in revs per mile on front vs rear drive axle. In the US, where we drive on the right side of the road, keep the larger tires all on the right, and the smaller tires all on the left to compensate for the crown of the road. .

Obviously I'm not a mechanical engineer, but my gut feeling is that with the front transmission in low gear, the torque multiplication would be too much for the 2" input shaft on the T200 series transmission to handle. .

Sounds like your transmission has the infamous range shift problem which was prevalent on the T2090, T2130 and T2180. Mack has updated parts that are supposed to be stronger than the originals. I had a T2130 do that sh*t too. Also had another T2130 that had bad O rings in the range shift cylinder that would leak air through from one side of the piston to the other when cold, resulting in no range shift until it warmed up. If that is the case, you can pull that range shift cylinder apart without disturbing the rest of the transmission, just remove the 4 long bolts that hold the cap on the end of the cylinder (located on the rear of the trans just above the output shaft), and pull the cylinder off exposing the piston. Check the piston and the inside of the cylinder for excessive wear and replace them if necessary, otherwise just replace the O rings and reassemble it. .

Guess I should have looked at that picture closer, I see now that it's an air operated grease gun. Speaking of grease guns that refuse to pump grease, I've gotten pissed off at quite a few hand operated grease guns over the years when they refused to "cooperate". I particulatly remember one occasion when I hurled one at the floor so hard the cast housing on the end busted all to shit, then I took it outside, placed it on the driveway and flattened it with the backhoe bucket of my 580 Case.

Probly because you tried one of those air operated Taiwanese grease guns, the type that put out one pump of grease each time you squeeze the trigger. I tried one of those too, about 20 years ago, and I never could see where there was much of an advantage gained by having to repeatedly squeeze the trigger vs just pumping a hand operated grease gun. Later on I bought one of those Lincolns like the one in your pic, those are nice, I still have it at the shop I work at now, only problem is the boss's son uses it to grease his truck and doesn't put the battery on charge, then I go to use it and it's dead! Not a big deal though, I just use the shop's power greaser instead. .

IIRC it can be pressed off, we had to do that back in '81 when we encountered the mismatched condition I spoke of in the earlier post. .

The "baby" quad box is a TRQ77 or TRQ770 depending on whether it is single or double overdrive, those are a completely different transmission than the TRQ 720, TRQ7210, and TRQ7220. The main box on a TRT7220 series triplex should be the same as a main box on a TRQ7220 series quadruplex, although I'm not sure about the drive gear at the back of the mainshaft that drives the compound countershaft. .

That's a TRXL 107 or TRXL1071 6 speed, and it would be behind a Maxidyne engine. I am aware that Spicer transmissions would have been available in a Mack by special order, however I was stating in the previous post that the O.P. had not referred to a Spicer transmission.

That's a combination double check valve/stop light switch that was used on those. Should be a Bendix part. Some had an aluminum tag with the part #, otherwise take it off and bring it to a truck parts store and match it up. .