I’ve been thinking about this and something’s not sitting right......
Why would you have a locker on while going downhill? You are not on the throttle at all in the situation you describe. If it’s that steep and loose, you are on the brakes only. With an open diff going down a hill such as this, the brakes control wheel speed, not the diff. If the surface is that loose, the tire’s ability to maintain traction is not dependent on the differential.
Now there are some ABS and traction control systems that do funny things in situations like this. Hopefully you can fully turn those off if you have them. My Explorer is pretty basic- ABS only.
Hi Tom,
In this scenario it is strictly an old school system without ABS traction control. A modern traction control system may actually be superior in the situation described below, but I've never had the balls to take an expensive vehicle down the type of trail I've done with old school (and cheap) vehicles. My trails usually have a vertical embankment on one side, heavy brush or drop off on the other. So if you slide into either side, damage to the vehicle will occur.
When going down very steep type trails with loose surface material, having a very low crawl ratio allows me to stay off the brake and crawl down using engine compression braking. With an open type diff, if a tire with traction that should be holding the vehicle back due to the crawl ratio is freewheeling because the opposite side tire is not rolling and sliding, you will gain speed and have to use your brakes as you described.
Here is the issue when using the brake...sometimes you start to slide downhill and or get sideways and you have to let off the brake and accelerate a little to get straightened up...but now your going too fast so you have to hit the brakes again....tires might start to skid so now you have literally no directional control especially with the front tires skidding. With a locked axle (or axles), no one tire can spin faster than the other on the same axle. You crawl very slowly and if you do start to slide a little sideways a little blip of the throttle can straighten you up and keep control of the car since all tires are rolling at the same speed....no front tire lock up or skidding down hill due to usage of the brakes. I've found that even if the tires a sliding when going down hill, as long as they ares still rolling you have some directional control. It's when they lock up that gravity is your new pilot. If the fronts lock up, you can't steer....if the rears lock up, the back end of the vehicle tries to come around on you.
I agree with you regarding the ARB lockers and air lines, leaks, etc....I do want to avoid that situation.
But, here is what I don't know about the Truetracs.....how do they act when going down hill in low traction conditions and you're only using engine braking and your crawl ratio to keep the speed in check and vehicle under control.
-Do they freewheel under engine braking?
-Do they have to have "throttle" to ramp up the gear engagement?
-I've seen videos of them working in reverse...does engine braking essentially make the Truetrac think that it's going in reverse under power so the "locking" part of the diff works?
I hope I've conveyed what I'm trying to describe....I have an article somewhere that explains what I'm trying to describe much more eloquently than me. I'll keep looking for it.
