Is there a speed limit when using axle interlock?

I asked the same question not to long ago. I accidently left it on about 8-900 miles. Doesn't seem to have bothered anything

 

Nah, mash your motor, it all spins anyway going down the road, however, if you are even using the power divider, it's more than likely not conducive to motor mashing.

 

This is an interesting topic to me. I know two log haulers personally who left their power divider on too long on dry pavement and had a rear end go out. It may have just been coincidence, because when I hauled logs I forgot mine on several times after I pulled out of the woods and never had a problem. The truck I have now has a loud buzzer that would give me a headache if I tried to leave it on going down the road.

 

The 2021 Peterbilt I drive will automatically kick it off at 40 miles an hour if I forgot to disengage it.

 

The CDL school I used to get a license had some early 1980s trucks (Intl ProStar cabovers). They each had placard by the diff lock switch warning of 45 mph max speed with the switch activated. Every truck I've driven since my second truck, say 1995-6, has no warning anywhere about a max speed. Out of caution and in an attempt to save wear and tear I leave the diff lock switch off except in muddy/snowy/icy conditions and always shut off the switch before 45 mph.
It's funny that in today's age with warnings on everything and for everything there are no warnings visible in the truck if there really is a mechanical reason to keep speed under 45. I don't see warnings in the owners manual for the trucks I drive either.

 

Now, leave your PTO on and you'll have issues.

A friend told me that.

 

Leave mine locked for probably 6 months a year each year (winter).

 

Once during my asphalt days, we were "burning circles", as per usual, when the boss comes on the 2 way, "I just found a pto power shaft in the road",,,you never saw so many dump trucks hit the shoulder, driver jumps out to check if it was theirs. Most trucks have a warning light, but the junk I drove for that company, the stuff never worked. Usually, the truck doesn't shift the same with the pto engaged, but a doofus might not notice it. Pumps too. I've seen power shafts that stayed put, but the pump isn't designed for 2000 rpms, and takes the seals out. In the past, you did that, you'd be out the door.

 

Not the best idea, it causes multiple problems like reducing ABS effectiveness, increasing the drives tendency to push the steers straight and makes it more likely to skid when you use the Jake and increasing your turning radius.

Driving in conditions like below I have seen several trucks end up in the ditch this week when they would have probably been more likely to keep it on the road if they had engaged the power divider when needed.or only up hill.



Remember that the sum of the RPM of each dual must be two times the RPM of the ring gear on an open diff that is powered.

 

Just the power divider locked won't bother when turning. But if the diff lock is on that's a different story.

If all the tires are about the same height leaving power divider locked in won't hurt anything.

Personally I only use it when I'm close to a bad situation. Never felt much benefit running it going down the road unless the snow is really deep