Long Distance with Interlock On?

Dude is not really a gendered term anymore. Also, who cares?

 

Yawn.

 

I have read where some people run on dry hard surfaces with the power divider locked on a regular basis. I suppose you can get by with that if you have a matched set of tires and are not turning a lot.
My experience with that is it can cause the power divider case or drive line to brake. If the tire circumference is different on sets of duels driving on hard surfaces with the power divider locked will cause extreme drive train pressures.
I have never driven a truck with front and rear axle lockers in the snow. With a little thought it is obvious why a three way locked tandem could send you for a bad down hill ride and a jake would make it worse. A power divider only truck locked in would just be half as bad.

 

Very gingerly on low, amirite? LOL

 

On Cats and two strokes not so bad, but Cummins....yea.

 

As a new driver I've achieved negative learning going through this thread. I assumed the OP being a technical question there would a couple answers but everyone just has an opinion or confounding sarcasm. Guess I'll just have to wait to ask at orientation.

 

There's actually a fair amount of good info in here. It's not always easy to pull out of the noise, but is there. The thanks given, and by whom, are a decent help.

And sorry to bust your bubble, but the folks who will do your orientation are most likely to be less knowledgeable as a whole than what you'll find here on TTR.

Edit: I should point out that you miss out on some helpful info if you only visit here on mobile. On the desktop version, you can see how long a member had been around, and the ratio of overall posts to thanked posts.

Edit 2: You can see that info on mobile, it just requires clicking the member's username. On desktop it is always visible.

 

You are much kinder than I was going to be, but it's Christmas...

Some "opinions" are not opinions at all. Rather, they are decades of experience of getting trucks and loads into places they have no right to go, in conditions most drivers will never come close to, let alone see, on time, intact and without breaking the equipment.

But, you're right, how do you differentiate (see what I did there? ) truth from fiction? Always go to the source. And, no, I am not talking about whichever twit is leading orientation. Oops, it's Christmas; replace "twit" with "fine employee."

IAD: Inter-Axle Differential, Power Divider
DCDL: Driver-Controlled Differential Lock, Diff/Axle Lock

The IAD lock may be used at all speeds and for long time periods depending on the road conditions such as rain, snow or gravel/dirt roads.

The IAD lock may be applied at speed (assuming both axles are rolling and that spinout has not started to occur) and/or remain engaged for long periods of time depending on weather conditions such as snow, sleet or rain.

That’s a very different situation to the DCDL, which come as an option for the forward drive axle, the rear drive axle, or both.

They should only be used at very low speeds because steering can be badly affected.

The DCDL is used during on and off highway operations that encounter slippery road conditions and/or uneven terrain.

It is used only at low speeds while travelling through an area with poor traction conditions and should be deactivated as soon as the vehicle is through the area.

Drivers may lock both the IAD and the DCDL for maximum traction under icy, snowy or poor road conditions.

- Customer Support - North America​

 

I STRONGLY encourage all newer drivers to actually READ ALL the manuals that come with your truck. You should find a large ziplock bag full of manuals for your truck, the Jake brake, the seat, etc. There should be a manual for the Interaxle Differential Lock (IADL) aka Power Divider.

You SHOULD also research further by going to actual manufacturer web sites to find out more about what you can and must do to use the tool.

I have one more piece of advice that is critical:

PRACTICE!!!!

If there's a snow or ice storm and you have a WIDE OPEN parking lot, then go to work. It's best if you are bobtail to start. Start in about fourth gear from a standing start and goose the throttle, with and without the power divider engaged. You should immediately recognize that if you DON'T have the power divider engaged you will start to yaw to the left.

Now try getting up to about 20 mph without the Power Divider engaged in high rpm with the Jake set on high and suddenly release the throttle. You should notice that your tractor will yaw. Do it again with the Power Divider engaged and you should notice you slow in a MUCH straighter line. The Power Divider not only applies force to both drive axles, it helps equalize force from side to side.

Do all that again when you are hooked to a trailer. Obviously you are doing this at slower speeds that highway conditions. The point is you are developing a sense of feel for where the point of traction loss happens and how you can WORK with it.

I always engage the power divider off road, in dirt or mud. I leave it engaged for days at a time if there are blizzard conditions. I know drivers up north leave it engaged for months at a time.

 

In my opinion, about the only time you are really going to hurt the power divider is if it is trying to engage and disengage while there is strong torque on the drive system or if you are actively spinning your wheels. Modern power dividers are really forgiving and won't usually mash anything up. And it doesn't hurt anything if you forget to disengage them once in a while. It burns up more fuel and it puts more strain on things trying to turn but it isn't like it is going to fly apart or melt down. Full axle lockers are a different story and you have to be more careful with how you use those.

I work for a company hauling oil from oilfield to refinery, mountains, pulling doubles. We engage the power divider when we hit the dirt and don't think about it again until we get back to the pavement. On the highway I use it a lot in the winter climbing hills. If the hill is slick at all, I flip the switch. We will flip that switch on as we go up a hill then flip it back off coming down the other side, then maybe back on again across the flat and up the next hill and so on. Never been told not to run it above a certain speed, but if it is slick enough I need it I'm not likely to be going over 55 anyway.