why don't I have auto locker? seems like that would have been something to include. I don't suppose it's something I can retrofit?
you hit on something (!) with the tracking because I do recall that from years past and I remember my puzzlement at the time.
Ackerman angle is what I'm talking about we know the left/right front turn at different angles, if it's set up right it will be exactly the Ackerman angle.
note that if your right front was turned all the way to the right (at a right angle to the right rear) the left front would still be at an angle. the truck would pivot around the right rear making three tracks.
normally of course the angle is less severe and the truck makes four tracks. why? because if you look at that picture you'll see the distances from the center are different for all four tires.
the wheels are fixed points on the truck so it has to be that way. in the pic it looks like the left rear will have the inside track, then probably the left front, then right rear, then right front.
you'll get 4 tracks. you'll never be able to drive so that it makes two tracks (unlike a lot of examples for steering).
the tires are always tangent to the circle they must travel in.
this pic below helps a little to visualize it. they only drew the circles for the right front and left rear, but if you took a compass and drew the other 2 circles, then it'd be very clear, there have to be 4 tracks.
as the steering angle gets less and less the tracks will get closer and closer together... but only at 0 degrees steering (straight) will you have two tracks
it was a surprise to me
all four circles obviously have different diameters meaning all four wheels travel different distances
if it is the situation that two differentials on the same truck must act exactly the same (I'm guessing that's true) then in order for there to be no fighting/binding between them,
the -difference- travelled between the two fronts, and the difference travelled between the two rears, has to be the same. I suspect this basically never happens.
in other words if the difference were the same, then both diff's could act exactly the same and, no binding. you could figure mathematically when does this happen and I bet you'd find out, if it does ever happen it would be a rare situation.
so that solves that part of it - wheels do -not- travel in the same circles.
now the rest of the question is, why do we see the slipping/dragging at the fronts? wouldn't it be just as logical for it to be at the rears? It seems like the rears take precedence somehow....
one of the differentials is going to be working to take up the difference, and it seems to be the rear, you don't see slipping at the rear, right? it evidences at the front, I think.
so if the rear is "working properly" (accounting for the difference left/right), it is forcing the front to behave the same say, but, the difference of the fronts left/right isn't the same, so it's being asked to do something it simply cannot.
I'm going to draw this out to show all the circles, if you know minimum turning radius spec and wheelbase and track you have all the info needed to find out what are the respective differences, that might answer some of it.
what I'm saying is the proportions of the circles of the rears, and the proportions of the circles front, aren't the same, and one of the differentials will work to take up the difference but then it forces the other to do the same
if the proportions of the diameters of the rear tracks were, say, 20' : 16', then the proportions of the front tracks would likewise have to be that same proportion, like, 25:20 and my guess is they won't be.
one differential is going to act to take up the difference where the proportion is biggest... or smallest.... and force the other to do the same, which will be wrong for that other axle thus the binding
the problem isn't that the left/rights are different it's the front l/r and rear l/r aren't different in the same proportions
we'll run it to ground yet