[urq] Diff Lock Question

[lawson.d at comcast.net]

>So let's see if I have this right. The recommendation is that it's OK to lock the center diff, but not the center and rear or rear only. So, I should be able to valve off the rear diff lock so that >if I pull the console knob, only the center diff locks. Then, if I do end up in the ditch, I can open the valve to the rear diff to get out of that jam. Does this make sense??? 

Get out and experiment with it, it's really not that big of a deal. Find a good section of road with twisties, run it with open, centered locked and full(center and rear) locked if you like. Just know, when you lock the rear the car wants to understeer. It's not like some crazy magnetic force will pull you into the ditch, but you can feel the car wanting to go straight. Many times I have run the back roads of Colorado, paved and dirt, with the center locked. The best way I can describe it is the car feel more planted. When I drive at the Steamboat ice track, I like to drive with both center and rear locked. The car understeers, but I can drive around it with different techniques like the scandinavian flick. Some of the other guys like only the center locked, it depends what you're comfortable with. On the pikes peak urq, we have that car setup with the center locked. 


As for the diff lock actuator knob(the pull knob), the stock 83 locks both the center and rear at the same time. Both center and rear vacuum actuators are mounted on the rear diff with the center using a bowden cable that goes up to the transmission. Go try it, I wouldn't drive around a mall parking lot, because it is hard to turn the car and the wheels do scrub. I've been working on the 80q rally car I picked up and I could barely get the car to turn around in the street. It turns out both the center and rear diffs were fully locked, no actuators, I'm talking a fixed rods bolted to the cases. I unbolted the rear actuator and released it, so now I can at least do a U turn in the street, even with the center locked. The car hops, squeals and leaves a bit of black tire marks, but it does turn. 


If you would like to lock the center by itself, you can change to a pull knob from an 84 4kq which has 2 positions, you would also need to run some vacuum lines so center and rear are different. It's all easily reversible and not permenant. 
Get out and drive, give it a try and report back. 
- 
Dave