DieselDog5.9

Have a 99 Mack RD686S that the stop lamp circuit has a mind of its own, looking for the stop lamp switch, but have found 4 switches in the air circuit, but not sure what is what.

There are numerous paramaters in the program that can be turned on or off. One of those is road speed, if the road speed is limited to 63mph, you are not going to pull full rpms out of the engine in top gear. I went to the mack garage and they turned off the torque limiting when on the low side of the transmission, and the speed limit of 63mph. The worst part of that 400 is the rpm range, it falls on its face at 1500rpm, but mine is a 2003 so maybe it is different. But I found a cure for that also.

Truck ran into the shop just fine, Changed the exhaust manifold and radiator now a miss, this all came before I touched the injectors. There is a specification of 14.34mm between the top of the cylinder head and the top of the injector when installing the injector but before putting the caps on, this is a check to make sure there are not double washers. After changing the injectors ran fine. It was before the injector change that it had a miss.

I have seen this setup in single axle plow trucks, the little peanuts come out and lock against the outer plate, but I did not think it was selectable, thought it acted as a locker/posi works in a car differential. Any Mack I have seen with "quad locks" has hendrickson suspension and Rockwell or Eaton rears.

Cracking injectors it acted like combustion was backfeeding through the injector line. 2 injectors and we are back in buisness.

I had run the truck for a while, longer than it should have taken, we were cracking injectors looking for cylinder contribution, and fuel started dripping out of the turbo exhaust. 😬 I had thought about swapping the eup's, was concerned about damaging the O-rings. Unfortunatly the truck really needs to run Monday, I have aranged a hired truck for monday if I need it. I had a spare set of injectors from an AI400 that went to the Mack Garage and was turned up to 460 when it was new, I swapped the injector in Cylinder no 4, runs alot better, cylinder is coming up to temp, still have a miss, cracking the injectors Cyl 4 has engine droop 5 does not and has a ton of air, almost like it is being pushed back past the injector. I will be tearing into it again, swapping 5,6 injectors with the spare ones I have.

Catching up on some maintenance, changed the exhaust manifold gaskets due to a leak, replaced the radiator, belt tensioner and belt. As part of this process had to remove the fuel jumper lines from the unit injectors to the cylinder head, immediatly put plastic covers on the unit injectors. Job went fairly smoothly however primined the fuel system, and got the truck to fire, definitly missing on No4, we cracked the line, checked the wires, no4 manifold cold, crack the line and no engine droop, definitly have a miss. I have done this job on multiple other trucks and they fire up and eventually work the air out. This spring I changed the fuel pressure regulator and took a few minutes for it to clear out. So not sure if I have an issue, with the unit injector or just need to let the truck run longer and work the air out.

My 03 Granite with an AI 400 has a thermostatic fan clutch not an air clutch. The thermostatic fan clutch is just like a car fan clutch it has an internal mechanism that locks up the fan when it gets warm, so there is no external control that you can tie into were the air fan clutch takes the temperature of the coolant remotely and turns the fan on and off with air, and that system you could tap into electronicly.

I have only done this job when removing the back box of the transmission to repair the Hi/Lo clutch. If I recall we jacked up the cab and removed the air bags so cab could be lifted higher, but watch the firewall of the cab hitting the back of the engine.

So my experience is with the 18 speed transmissions, but assuming they have similarities, front box has 6 gears, rear box has high low split and reverse. In my opinion you have an o-ring that is cracked and allowing air into the case, now in the 18 speed the rear piston is for high low, and can be replaced externally. The reverse piston I think is on top of the transmission.

I was assuming also that it was the overdrive version. 5th being direct? From the conversation the Owner and I had noisy all the time, hi or low side.

So we pulled a 6 speed out and put a 12 speed in 3-4 years ago. The hired driver, (nice guy, just young and inexperienced) had to drive the old R model while the Granite was out of commission for a few days........ Well now 4th gear is noisy in high or low, so thoughts? I think there are 2 versions of this 12 speed, one for off highway trucks a little lower geared and a highway version, we have the highway version.

Is the T310M the ten speed with selectable reverse, similar to an old twelve speed? 5 reverse gears, yellow selector lever?

Just got a quote from Mack for 2 new rails. 26k not installed. Our frame is not awful rusted but the spread is bad. 3/4 inch. Cannot just get a whole frame rail from supplier because an R model frame is "Fashioned" in the front and they do not do that only straight frames. Guess I am looking at 2 options: Cutting the outer frame off, sand blasting and putting back together and welding. Reading here I see some have done this but couple of questions. Where is a good spot under the cab to cut that you can get under there and weld back together. Will the frame come back together as it is spread pretty far apart from original. 2. Pull the inner frame rails out Lots more work but no welded joint Will the frames come back together What is going to be a complete SOB when pulling the inner rails out? Would love some more pictures of some others experiences with this repair.

I had a friend put a marine engine in a superliner, had to come up with some jakes and rework the pump for variable speed governor.

Whoever posted this is my hero.

A few buddies of mine LOVE the 12 speed in dump trucks. I could sell every 12speed I could get my hands on.

As it is 65 mph is 1800 rpm

I would have to buy a fuller 18 speed $5,000, find the fuller linkage and bell housing, Lengthen the drive shaft. I have $1200 into the Mack 18 speed.

Woops, I made a mistake, just went to the file to verify from the specifications Mack gave us from the VIN: 4:64 rears T309L Transmission

Does someone have a chart with the ratios for both transmissions so I can compare. They made a 2100 ft/lbs torque version IIRC, for the cummins and Cats that you could get, Odd to me you would get a Cummins engine and choose a Mack transmission but I guess. I thought that was the 2180B It would appear they are the same front box, but the rear box makes the 9 vs 18. I have 4:64 rears and with the 9 speed it is just right for a trailer, 70mph is out of the question, I think the 18 speed would give me a reverse with a high split. I did a 6spd to 12 speed swap before, and they apparently had an off road version and an on road version well just my luck I put a highway trans in a dump truck, worked out better than the 6 speed but still would have liked the off road version. 12 speeds are hard to find. That extra gear between 8th and 9th is really what I am after.

Have a CV713 Granite, with an AI 400 that is finicky to drive, (working on the cure following the dead dog thread closely) however just need more gears. Current Transmission is a Mack T309L/LL great low speed reverse and low gear, short on gears in the high side, the rpm spread in the gears is to wide for the limited rpm range the Ai400 makes power in, and a mean shifting SOB. Solution: picked up a transmission the owner states is and 18 speed, makes noise when on the low side. This transmission is a T2180, not sure about any particulars, suchs as gearing and what not, my truck being an 03 would be a 300 series transmission, is this T2180 a bad choice? I have a lot of experience rebuilding Eaton Fuller transmissions, I have rebuilt the back box on a Mack 18 speed 300 series (318L/LL Maybe) and the parts are somewhat pricey for the HI/LO clutch pack from Mack. Originally I was going to swap a Fuller 18 but thought going mack for mack would be less fabrication an coming up with parts.

Ice was totally blocking fuel line

The perfect transmission is an 18 speed, has an overdrive and a deep low gear. With these transmissions you have one or the other, 13 speed you can split shifts on the high side and you will like that if you are traveling in the 45 to 70 mph range alot. 9 speed has a low that you will like on the jobsite.

I am going to add my 2 cents, just read all 4 pages, and live in the north, probably similar climate to Sledog, and spent multiple days last week getting machines started due to the cold. Put 2 new fuel filters on. When the fuel filters are off, pump the primer and verify fuel is flowing to the filter, and work systematicly through the lines verifying that fuel is getting to the fuel rail. For me when a truck runs then dies and it is cold out I suspect jelling. This time of year is more prone to jelling as summer fuel is in some of the bulk tanks still, and will gell at 30 degrees, It was 10 degrees here, sure Rochester is the same. Once gelled the wax doesn't go back to diesel without chemical treatment. Any low points in the line can accumulate water and freeze. Attatched is a photo from a skidsteer last week low point in the line collected water, primer would pump fuel through the line to the filter but put the line on and wouldn't pump a drop. Machine started then died, wouldn't start afterword. Use some diesel 911 in the tank. Red bottle. I will work on attaching photo, missing some technical skill for that.