Challenger

All the range shifts are done in the rear case by the rear top cover. Looking at the rear top cover the direct-lo shift is the cylinder, the other shifter is reverse-N. Inbetween the the cylinders is a detain pin that is suppose to prevent forward gears and reverse gears from engaging at the sametime. You probably have a worn shift rail that is sliding pass the detain pin allowing 2 gears to engage. My guess--worn rear topcover shift rails and orings. Orings should always be replaced when the rear top cover is removed.

80w 90 gear oil is the trans oil. What do you mean by locked up? Does it get stuck in the selected range(Direct, lo, N, reverse) If its getting stuck in selected range and flipping the switch back and forth releases it, maybe you have an oring problem in the rear top cover. As you select the range gear on the shifter do you hear the normal click and clacks? Or does it sound slow? When it locked up do you hear any steady air leaks? Changing the trans air filter is always a good idea but if you go from lo to direct fine, I dont see how the air filter can be causing a problem.

Injector cups are a big problem. Its safe to say every Mack and Volvo will have the problem. The injectors sit inside the cups. Basically the injectors move very slightly and compression leaks pass the tip and gets in the fuel system causing hard starting and and low power. Even if you werent under warranty, all 6 cups should be replaced.

FMI 5 is an electrical problem. Open circuit, Bad injector, break in the harness or bad EECU. First guess would have been a bad connector to #5 injector. Mack had problems with the connector terminal heating up and loosening. But since you already replaced the harness its probably a bad injector. If it was me I would replace the injector. The air in the fuel system would be from bad cups. You would have, hard starting, low power and maybe injector codes with FMI 7. You could swap injector 4 and 5 and see if the code follows the injector. I would replace the injector and be done with it.

Lightening bolt is the malfunction light X is the shut down light. Shutdown light comes on for something that can damage the engine. Coolant temp, coolant level, oil pressure, things like this. Check your coolant level.

A 2001 shoud be an Etech. Does it have an engine brake? Are there spring loaded push tubes? Are you pushing down on the rocker to take out the push tube spring play while adjusting the valve?

The 3 position switch should be your engine brake. Do you have an exhaust brake? If you have an exhaust brake you will see it on your exhaust pipe. If you dont see anything on the exhaust pipe, you dont have an exhaust brake. I dont think Ive ever seen a vision with an exhaust brake. Does your cruise or high idle work? If not, it could be a clutch switch out of adjustment. The switch is mounted on the clutch pedal. Push the clutch pedal down and you should hear it click.

Take it back for warranty. Tell them you want the fuse diagram too. I hate when people take them out and leave them out.

Check you fuel tank for trash or large contaminants that could be blocking the pickup tube. We had a truck that would run fine and then just run out of fuel. Shined a light in the tank and found the fuel cap lock inside the tank. We've found alot of other trash over the years to, napkins, gloves, gravel but these were put there on purpose. The fuel cap lock just broke off and caused problems.

The older Volvo trans were replace only too. I've only seen a few and they were in Autocars. I cant remember what they were called. They seem to last awhile but when there is an internal problem, start looking for a new or used one.

Not all the time, when it does happen I just assume the last person who install them was a gorilla.

Got 2 more Ishifts on the ground needing replaced.

Could be a loose synchro fork pinch bolt and or a synchro failure. Mack has the tools to do a "inframe" synchronizer replacement. Every truck is different, it depends on how much room you have to work with. You can do an inframe synchro on a Granite in 6-8 hours. I did an inframe on a RD one time. The rear of the cab had to be unbolted and lifted up, it was a total waste of time. Pulling the trans would've been easier. The trans is a T2180

Another vote for possible injector cups.

Warranty is PRICELESS.

They better.

Another thing is, every new trans needs programmed and the clutch calibrated to get the truck moving again. So after warranty runs out and you replace the trans at your shop, you still have to tow it to a dealer to have it programmed and calibrated.

Usually around 200,000-300,000 miles they need replaced. The only replaceable parts were the TECU, top cover, and of course the entire trans. So ANY kind of internal damage resulted in replacing the entire trans. The input shaft bearing has a end play reading of 0". So any play in the input shaft resulted in trans replacement. 7 out of 10 trans were replaced from this. Im no engineer, but having a single countershaft and an input bearing with 0 endplay sounds like trouble. Volvo just came out with partial rebuilds. 1 complete rebuild 2 main case and rear case rebuild. This one doesnt come with a top cover or TECU. You would use the ones off the old trans. 3 only main case rebuild. You would have to use your old rear case, top cover and TECU. I wouldnt say its a bad trans, just the fact that you cant replace 2 gears and a sliding clutch makes it different.

We still get parts and technical help for Volvo D12a,b,c. We havent needed much tech help with the old girls but Volvo did point us in the right direction a few times.

The brake switch would be behind the drivers lower dash panels in the air manifold (atleast I think so). I dont think this will be something you can repair in the yard. In fact, I dont think there is anything that can be repaired or replaced on the M Drive/ I Shift outside of a dealer. On a side note, we have 3 IShifts (mdrive) on the ground being replaced.

Maybe you have a problem with the hill assist staying on. I THINK there is a brake switch and a sensor inside the TECU that determines the degree of hill the truck in on while hill assist is activated. Maybe the hill assist is staying active due to a bad brake switch. That could explain why pumping the brakes gets you moving. Take it to a dealer.

Got to love it when its an easy fix.

Got it. I would think your complaint is just one of the differences between Dynatard and Jakes. I dont think you can change any parameters for the engine brake. As far as I know, you just have one parameter box to click for the engine brake, on or off. Everything else is set by Mack.

I can take my chances with hurricanes. I think I can give up Pittsburgh's winter scenery for tanned oiled asses.

4-2 Fan clutch output. Is your fan operating normal? Your fan clutch solenoid operates the fan clutch, it turns it on and off. Its located on the top mounting bolt for the air filter housing bracket. Its black and brass, with 2 airlines and 2 wires going into 1 connector. The solenoids go bad. The fuse for the fan clutch is in the fuse box above the driver front steer tire (EPDM). I would replace the fan clutch solenoid and see what happens. This is all assuming you have an air operated fan clutch.