Did I damage the diffs?

Make sure the breather on the diffs isn't plugged up. Over looked item

 

I’d lock mine up in October and unlock it in April. When you’re climbing a hill you only have one shot and 99% of the time you’ll never get away with locking up after you’ve already spun out and making it up the hill under your own power. And pulling Super-B you’re always dragging a load that’s not over your axles.

 

I thought they were locked. Old timers told me that.

 

Flip the switch back and keep on trucking

I do rears and trans every other year and breathers, grease once a month but I don’t do 5k a month,

maintenance is cheap, replacement parts are not

 

I was told the same.

If you put the transmission in neutral, and jack up the rear end and spin one tire forward, the other side will spin backwards. That signifies the diff is open. If you spin the tire forward, and the other side spins forward, the diff is not opened, but is either locked, or limited slip/positive traction.

Almost all big rigs are open diff to keep them from binding in turns and grenadine diffs and axles. The ones with lockers will be air actuated lockers. Lockers aren’t common in trucks that mainly see asphalt.

 

I know on my old truck, if you flipped the side locker switches......they were locked.....end of story. You positively didn't want to do it on dry ground when loaded or make very sharp turns with them engaged. It would push your front end and tear up your rears with a quickness. Usually snap and axle and then what ever carnage followed that, depending on how fast you could get stopped. However, I've never owned a newer truck, so maybe that has changed......to fit the new style of driver these days.

 

I got the "lock" switch on my 14 cascadia. I use it 4 times a year. I do the same. Stop, neutral, turn on go 10 or 30 feet, stop put in neutral and turn off. It plows forward.

 

I'm not trying to be harsh or be a dick all the time......I'm really trying. You have to live and learn. However, a truck/trailer is a large expense. It is your business and livelihood and not something to be taken lightly. I'm not gonna lie, I'm hard on the new crop of drivers. Haven't met very many I like very much and I'm not afraid to tell them that. All that being said, it is a good idea to know how things work and function (especially when you depend on it to make a living) before you are knee deep in it. Fluids are a very basic thing. If it has a fluid, it's gonna need to be maintained, same with grease. You need to learn how to maintain and operate your equipment, not just hold the steering wheel and you will be much.....much better off in the long run. I sincerely wish you well in your endeavors. Don't be discouraged or afraid to ask. Everyone is different and these are different times. It's hard for me when someone questions things that I learned when I was in my teens. Anywho.....good luck.

 

Why don’t you just get an OA on the diff fluids?