JoeH

Pull out any 92/93 book and look up inter-wheel in the table of contents. Its there. I believe mines dated 1986.

Checked the oil pan for water today, had a little bit of accumulated condensation from sitting for nearly 10 years. Drained that out. Oil level is maybe a gallon high, might drain a bit out.  Coolant reservoir is good. Untangled some of the rats nest of harnesses, air lines, fuel lines etc that were coiled on top of the transmission. Dragged the battery cables out.

Before I gut this cab to make way for all the wiring etc from our 2003, we're gonna dip the fuel lines into a bucket of fuel, toss a couple batteries in and see if we can get this motor to fire up!  Just want to know it's a runner before we pull anything apart.

We did bar the engine over a couple turns and it was tight. Good compression, barely broken in.

I would not put a 2800rpm give spring anywhere near this motor, all it takes is one screw up and you're floating valves and smashing them against pistons and now you're into needing that spare motor.

Are you sure you can't back off a travel stopper bolt? Much like the idle adjustment screw.

2100 is your maximum governor target. The precursor endt676 motor which is pretty much an E6 with a 2 valve/cylinder head, allowed 2300 when shifting, but was governed around 2100.

I think the frame side of the trans mount is the same, but the trans bell housing side is different. Uses the same rubber donut isolators I believe.

I'll still hold that a donor parts engine/trans combo is a good idea. Even if you don't need the spare parts engine, it'll have the flywheel and housing to match the transmission.

What's a common application that would have been buying the inter-wheel locks? Fire trucks? Municipal Plow trucks? 

I've seen 112/113, 150/151, 200's mentioned, what are the differences? The 92/93 book mentions the 112/113's.  Are they weight ratings? Generations? Housing differences to accommodate taller ratios?

Obviously you'll have to have a new driveshaft made up as the trans will likely be a different length than your current one.

I think if you had a strictly mechanical auto trans to put in there you'd be ok to swap transmissions, but you'd likely need to come up with a flywheel and possibly flywheel housing specifically for an automatic. You'll have gear control over the auto, so you can cap it at 1st, 2nd, 3rd for speed control to keep your engine speed up to keep your air compressor pumping for your brakes.

Finding a donor engine/trans from a firetruck that matches your current engine is a great idea, though you don't have to swap engines. Just flywheels etc.  Never hurts to have an engine for spare parts!

The service manual on the 150/151 carriers shows an air cylinder with a wire pigtail for alarm sound in some of the pictures for the CRD1501/1511 inter-wheel locking differentials, but the CRD92/93 book is largely lacking on showing any possible variations in the carrier housings to accommodate any sort of air actuated differential lock.

In my hunt for off-road traction for my concrete trucks, I've come across some interesting info.  Older CRD92/93 rear carriers apparently had a limited slip style differential option, and those carriers would be CRD921/CRD931. The newer CRD1501/1511 version uses an air cylinder with fork to slide a locking clutch through the differential to lock it.  Does the CRD921/931 do similar? In the CRD92/93 service manual it seems to imply that it's an automatic torque biasing cage with wedges much like the automatic inter-axle power divider.

Does anyone on here know anything about these rears? I suspect trying to aquire a pair of these differentials would be like trying to bottle unicorn farts.

I was more so thinking that they hacked the rear frame down at an angle because they have some steep jumps to drive over, and the trailer would otherwise interfere with the rear of the frame. 

It certainly does look like the trunnion may have been slid back, there is some weird metalwork involved on the rear of that frame.

E7 boasts being about 16 lbs lighter than an E6 on account of having a smaller, more refined water jacket. The E7 is a wet/dry cylinder sleeve assembly. Top half of the sleeve is wet, bottom half dry. I forget how many quarts less it holds, but it's enough to make the E7 with coolant lighter than the E6 with coolant, even though dry the E7 is heavier.

The E7 is a 12 liter displacement engine vs the E6 is an 11 liter displacement.

If you ever have to do wiring repairs, every wire has a code printed on it that tells where it goes. Example in the wiring diagram for this vss sensor, VJ2-12-1.0 indicates it originates at VECU plug J2, pin 12, and the wire size is 1.0.

Didn't like the first picture, it was a bit blurry.

Do yourself a long term favor, buy Mack Book part number 8-211, it's a list of all fault codes, plus their possible solutions. Here's page 1 of code 4-1: it shows under Additional Symptoms that reduced power option may be enabled.

Did you do multiple code requests? One request blinks out one code, so after the first code is done blinking, punch the cruise control to blink out the next code.  Keep doing this til the codes start repeating.

Which is another reason why I'd love to know what your adjustments are set to.  If your adjustments are set properly and maintain adjustment well then I'd be wondering about the treadle valve not regulating out enough brake pressure.

Its also possible if you don't know about the reverse slacks to install them on the wrong axles even if they gave you two and two.

On 12/6/2023 at 7:50 PM, Moparmike said:

biggest reason for the change was a few didn't adjust (SELF) so I just replaced all 4

all the 1s I took off was on the truck when I purchased it about 7yrs ago

 

and most times I try catch fleet pride deals on drum and brake kits change most stuff all at once 

On the intermediate axle of Mack Camelbacks, the slack adjusters are mounted "backwards" I believe, so is it possible you have the new slack adjusters installed wrong? The rearmost axle adjusts normally, but the intermediate axle requires a reverse action slack adjuster. Your parts dealer should have given you two and two different adjusters,  not four of the same.

When we bought my 1995 RD688S it took us a while to find out why the one wheel was always walking out of adjustment. The above is why. Previous owner installed the wrong style self adjusters.  This truck now has all manual adjusters.

After a certain year, I think around 2000,2001 you're not allowed to use manual adjusters, but I think if a cop pulled you over and you explained a) brakes are all adjusted and b) synchronized I don't think he could argue with you other than if he's a complete ass and c) you know exactly where your brake lining life is at.

On 5/28/2022 at 12:48 AM, Mandrewoid said:

Here are some progress photos. Centering and squaring the plate for welding was easier than I thought, and no additional wobble was incurred.  I am cutting some additional pieces for reinforcing the inside, as I agree it will put excessive stress on the edge of the center rim if too much weight is borne by the outside wheel. 

I also have to make a few small blocks on the surface of the flat adapter to "hub pilot" the outside wheel, as I don't think that I want to get into the complications of special lug nuts. In this photo, the third wheel is secured by  1" bolts. I am considering the possibility of purchasing knurled studs, does anyone know where I could get 40 26mm knurled studs?

I want to know how this monster is doing! How have your third wheel adapters been working? It's been a year and a half now!

I wish I saw this thread when it started! You can run 315/80-R22.5 on 9" wide rims as dualies, no reason you shouldn't be able to run 3 across!  They'll give you wider tires for more flotation.

Those transmission models are from my minimal experience. I have a 2003 MR688 that has the HD4560, and just picked up a front cutoff of a 2000 MR688 with the HT740.

The computerized HD4560 has a top mount PTO port as well as a driver side PTO port.

That's a monster of a truck!

Is the transfer case for AWD bolted to the transmission or is it a standalone unit further back? I know what you mean on finding people who can drive something other than an automatic.

If you do try to put an automatic on there then you need to do your research, and you'll need a donor truck year 2000 or older. 2000 has a cable shifted Allison HT740 mechanical (I think) transmission, with the only PTO port on the top of the transmission.  By 2003 they switched to an Allison HD4560 computerized automatic.  

I don't know how the automatic transmission's gear ratios will do going up those inclines, I don't think you'll be going any faster up that hill.  Looking at your bumper I'm guessing the top mount PTO won't be an issue because you're running it live on the engine.

I have those zip ties on all my trucks with self adjusters, and in each truck I carry a 3 inch scrap of flat bar with quarter inch gradations on it under the seat. Gives a quick reference to know where your brake adjustments are.