HK Trucking

Well then somebody must have stuck an old cab on your 85, cause the gospel truth is that the larger type cab with the back wall extended out was introduced in 73. Don't take my word for it, check with the Mack museum.

Actually it was the 66 to 72 models with the smaller cab. In 73 on up they moved the rear cab wall back a few inches, changed to the newer style dashboard & used the adjustable steering column.

From the previous post: Actually it was the 66 to 72 models with the smaller cab. In 73 on up they moved the rear cab wall back a few inches, changed to the newer style dashboard & used the adjustable steering column. But this is irrelevant if they're just interested in the engine & driveline.

The end yokes (that hold the U joints) are normally welded to the tube section of the driveshaft. If there is any welding on the tube section itself that is not acceptable. (Except for small "tack" welds to hold balancing weights to the tube).

Where's the Bulldog?

That's not an "M". Look closely.... the trim at the top of the grille, directly under the bulldog is definitely shaped like a "V". "V" stands for *$%#@*!%^. (I can't bring myself to type that word)

Here's your info, scanned from an old Motor truck repair manual. I've got a bunch of old Motor manuals from the 70's all the way back into the 40's. If anyone needs any info, I'll scan it & post it on here.

It looks like a fat guy who tightened his belt too much.

ENDT 673 with no letter after it would be 205 H.P. ENDT673B would be 225 H.P. ENDT673C is 250 H.P.

On the 4 valve engines that I've been around there is an ID plate on one of the valve covers with that info. E6 is the engine family, followed by the horsepower rating. The E6 4 valve engine was produced thru 1989 or so, then the E7 was introduced about 1990, so depending on what year that CH model is, it could be an E6 or an E7.

The numbers are stamped in the block, just ahead of the inj. pump, on that curved area right where the timing case cover bolts on, unless it was originally in a cabover truck, then the numbers could be on the rear of the block, just below the head gasket. If it's a 250, the model numbers stamped in that area should be ENDT673C.

Maybe you should disconnect the "pain sensor" in your back & keep running the superliner. A superliner is way more of a truck than a vision. IMHO, air ride is not the hot setup. Just my .02.

Valve settings (cold): Intake-.016, Exhaust-.024 Here are scans of some pages in the Mack book on this subject: Hope this helps.

Amen to that.

Trent, you have a PM.

Congratulations Trent, the truck looks great. Just be sure to insist on a decent rate for whatever work you do with it. Don't know how the business climate is in the Chicagoland area, but around here theres so much cutthroat sh*t going on, pretty soon everybody will be working for free! I got to the point where theres only 2 companies here that I'll haul for, if they ain't got no work, I stay parked. After almost 33 years driving truck, I ain't gonna just do it for practice.

I've always greased all my stuff every 5 working days. Mileage doesn't mean anything on a dump truck, there's been times a truck could go 2 months without getting 5000 miles on it, if it's on site work or a short haul. I change oil & filters every 300 engine hours also for the same reason. "Grease is cheaper than parts & it's a lot easier to install"

An 8LL definitely wouldn't be factory installed behind a 237

It certainly is a 2 valve. Note the valve covers. It's an ENDT675 237 HP if I've ever seen one. The more I study that photo, the more that whole setup appears to be mid 70's vintage, or possibly something that was stuck together using parts from various year trucks. The motor has the spin on filters-72 or newer. That radiator support looks like ones I've seen on late 60's models. The engine has the cast aluminum intake manifolds- mid 70's or later. Dry type air cleaner- 73 or newer. I would also conclude it's not an 88.

Hey Chuck, now that you brought that to my attention, it has the firewall to radiator support rods- I think they stopped using those previous to 88. The ones I've seen from that vintage have a rod from the top radiator tank extending diagonally down to the frame about halfway between the cab & radiator. Also, you're right about the radiator, that looks like the 700 sq in radiator like they used in earlier models with 673 & 711 non turbo motors. The factory radiator with a 675 -237 HP would be the 1000 sq. in with the cast aluminum top tank. From what I've seen on trucks I've worked on or driven, R models from about 73 on up should have the "viscous fan drive" as the parts department likes to refer to the fan clutch. I would still recommend the "modus operandi" of my earlier post if they really want to put an aftercooler on it. Herb

You could find a tip turbine aftercooler setup from a 285 H.P. & it'll bolt right on there in place of the existing intake manifold, but you'll have to put on the 2 element air cleaner to supply it with cool air, also put a turbo from a 285 on it, and now that you've done all that, you might as well put an injection pump & injectors from a 285 on there also, cause all that cool air ain't gonna help much unless it gets more fuel too.

I can tell you that for a Quad axle dump truck with a 156" stroke cylinder, 35 gallons is enough. when I've drained systems & refilled from scratch, thats how much it took to fill it up & top it off after bleeding the hoist cylinder. However much longer your cylinder is on your trailer you could estimate the gallonage accordingly.

Glenn, now that You mentioned head gaskets, Didn't the ENDT 673 A & B have the old type head gaskets & the C had the fire ring set up, just like the ENDT 675 maxidyne? It's been over 20 years since I've had an ENDT 673 apart, but I remember working on a B without fire rings, and a C that did have fire rings. Herb

On a 237 it would be Stamped "ENDT675" with some other numbers following that indicating the serial #. On engines sold in the US there is also a tin ID plate attached to the side of the block, directly above the inj pump, behind where the high pressure lines are. This plate indicates what year the engine was certified to meet US emission standards, and if I remember correctly also has horsepower ratings on it. Not sure if engines on your side of the pond would have that ID plate. Also (assuming no one has substituted different valve covers) there's a nameplte on the top of the valve covers that would say "Maxidyne Diesel". (On your 673 the valve cover nameplate would indicate "Thermodyne Diesel") Looking at some old literature here, the Horsepower on your 673 was 180, Vs the 237 you'll have now, but the real difference is the torque which is501 lbs.ft. for the 673 Vs 906 lbs. ft. for the 675. There has been some discussion here in the past as to whether the single countershaft transmissions TR, TRD, TRT, & TRQ 72 , 720, & 7220 will handle the increased torque of a maxidyne engine. I have swapped a 237 into a truck with a TRQ7220 quadruplex, and have swapped a ENDT 676 (285) into another truck with a TRQ 7220, and the transmissions handled it just fine. It's just like anything else, if it's driven respectably & sensibly it'll last forever, but if someone abuses it, it'll break. After giving this some more thought, your B model almost certainly has the push type clutch, whether it be a single disc or double disc type. All of the Endt 675 237 HP motors I've seen have the pull type double disc clutch (with the exception of the few that had that assinine Dynamax wet type clutch), however just use the flywheel & clutch from the 673, it'll bolt right up to the 675. While it's apart check the clutch disc or discs for any cracking in the center near the hub area, replace if questionable, I've seen quite a few of those tear the center out, that would be a bummer to have that happen right after the transplant. Also, if using the original bellhousing that comes with the 237, make very certain that the bolts holding the housing to the engine block are tight. These had a way of coming loose at times, and the resulting flex between engine & trans is what causes the clutch discs to crack around the hub. If changing to your old bellhousing, the bellhousing should be dial indicated to ensure it is concentric with the crankshaft, as misalignment here can also cause the discs to crack. During your junkyard engine search you may also run across an ENDT 673 which looks externally to be identical to the ENDT 675, except that the ENDT673 was usually bluish green, and the 675 was gold, copper colored or for the later ones, grey. The ENDT 673 would also be an excellent choice for a re power, these were rated at either 225 or 250 horsepower & 653 or 700 lbs. ft. torque depending on whether it's an ENDT 673 B or C. I'm digging way back into my memory and my old literature for this, hope it helps & if you have any other questions I'll try to answer them Herb

Sounds like you're considering swapping a 237 into your B model to replace your 673? It's basically a bolt in swap, everythings pretty much the same, you have to use the water pump & housing from the 673 cause its shorter. Other than that just make new intake & exhaust piping to accomodate the turbo. If your truck has the lower right side mounted starter, you'll have to swap your original bellhousing onto the 237. Good luck, you'll enjoy that 237 in your B model.