HK Trucking

Sounds about right to me.

Larry, the compound is overdrive in hi split even on the "72 & 722" transmissions. The main is also overdrive in 5th on the 720 & 7210 & 7220 transmisions, which gives them a double overdrive.

8.24's were usually used with a quad box & 11:00x24 rubber, & IIRC my B81 was good for about 52-54 MPH @ 2100 in 5th hi. I'm guessing (without doing the math) you'll be at about 48 MPH @ 2100 in 5th hi. 7.49's were the ratio usually used with a quad box & 11:00x22 rubber.

Just replace the rearmost housing with a cast one, save the other cast housing from your spare set of tandems for the next truck that has that issue.

We tried OEM & Hastings. That's the only 2 brands they buy. same results with each.

That happens because the transverse torque rod is constantly trying to tear the diff out of the banjo housing every time the truck goes around a corner. I've welded them before, as long as you vee out the crack, get good penetration & then put a reinforcement plate on the outside of the housing, it will usually stay fixed. The other way to solve the problem is to find a used "cast" banjo housing to replace the fabricated one. The cast housings don't crack under those conditions. Cast housongs are getting hard to find though, because most have been bought up for just that reason.

Trent, those air cleaners on those are just about at their limit even with a stock C15 motor. At Trico they've got some Paystars with that setup. You can install a brand new OEM filter, put a machine on the trailer, & as soon as you get put on the road & get the engine pulling hard the restriction gauge gets sucked right to the max.

The ENDT 675 237 Maxidyne was a 672 cu in engine with a 4 7/8 bore, same as the 673.

If it's a 58 then somebody put a later model radiator top tank on it somewhere along the line. It has the high tank that was used from 63 on.

Either that or they're keeping their communications about it in PM, so we can't see it.

Could be that proportioning valve under the front bumper is defective & not letting any air through.

Camelback springs are the only way to go. When I was running my fleet I decided to try air ride, found a used CL with the Mack (Hendrickson) air ride. Big mistake!!!!! That truck was paralyzed as soon as it left the pavement. Locking the power divider helped some, but when you lock the power divider you are over torquing the axle that does have traction. Learned my lesson & sold it after a couple of seasons & replaced it with a different CL on camelback.

Mack serial #s back then started with 1000, so that's the 231st one made. As said, it would have the END 864 naturally aspirated V8, and since it's a heavy spec DM 800, I would bet on the Quadruplex transmission.

Happy Birthday Rob!!!!!!!

Chipped bull gear??? A worn power divider jumping over is usually irregular & happens under a hard pull.

In most states unless you have an overweight permit you're allowed 20,000 lbs on a single drive axle, & you can run 20,000 lbs on the steer axle also, but only if the steer axle & steer tires are designed to handle that weight. Most single axle trucks have a 12,000 lb steer axle, so you get 20,000 on the drive & 12,000 on the steer which equals 32,000 lbs gross.

Long as they're installed correctly & trued up, they'll run straight as Budds. Those double nut Budds are the thing that really does suck, in my opinion. Unimounts aren't bad, but of all of them I'd still prefer a nicely painted set of spoke wheels.

Awesome!!!!! Finally!!!!! Someone is buying a truck with spoke wheels & they're going to leave the wheels alone!!!!! Usually the first thing that happens is that the new buyer comes on here wanting to know how to convert it to aluminum Budds.

It could be that the O rings on the piston in the deep reduction cylinder are shot, allowing air to leak from the "pressurized" side of the piston to the "non pressurized" side of the piston, and then the air flows back thru the line and comes out of the exhaust port on the control valve. If this is the case, then it's possible the previous owner intentionally disconected the deep reduction so that prospective buyers wouldn't hear a massive air leak if they flipped the deep reduction switch.

Not being egotistical at all, anyone who knows me personally knows I'm not like that. I just cringe when I hear a transmission being abused by someone that doesn't know what they're doing, hence that tagline on my posts. If you don't like what I post, then don't read it.

The ratios don't work out for split shifting anyhow. You would think that after trying that once they would have realized you're not supposed to drive it like a 10 speed.

That will be all well & good until the truck gets into some soft ground or has to start off loaded on a steep hill & the driver smokes the clutch trying to get it moving without lo lo.

That's a disease with the Mack 9, 13 & 18 speed transmissions. The Hi range/lo range synchro starts acting up, causing a terrible grind on the first few shifts when the truck is cold, then it keeps getting progressively worse as time goes on, which leads to the teeth on the hi/lo shifter getting worn down to the point that the trans will jump out of gear when you put the power to it. As Rick said above, Mack has updated parts available that are supposed to cure this problem. Another way you can avoid the clashing on cold upshifts is to shift by going from 3rd lo range to high range on the button & lo on the stick, then shift up from there in hi range. This allows the range shift to take place at lower transmission rpm, hence less strain on the range shift synchros. I had one that started clashing when cold & I nursed it along for quite a while by shifting it that way until it warmed up.

If it's a bone stock 24v71N as previously stated, then it's basically like 4 6-71 motors put together. A 6-71 is 238 HP, and 238 X 4 = 952 HP.