mgonzo700

Ok dont know if this the right section for this but here goes... a while back I went out of range with my dbx and I didnt have fail safe so it ran straight into a wall at top speed. Yesterday I got all the parts neccessary to fix it including the chassis and I finished putting it togethor. Now it seems as if the rear tires are locked. The rear drive shaft doesnt want to spin unless you try hard. Is there anything I could do this is my first time putting a car together. Thanks

J4K3SHNEG

Do you men that you cannot spin them even when off the ground? Because you might have put a front or rear differential in the wrong way so that the front and rear wheels are spinning on opposite directions. If not then your probably just gonna have to take it all apart and find out whats causing it, i don't know i don't have a DBX so i don't know if its a common problem but try that.

olkleaf

check your gears for rock pebbles or anything

mgonzo700

Yea I can spin the tires of the ground if I try to spin them hard by hand. I guess im gonna have to take it apart and see if I find anything. Thanks anyways

Spiro

I went through a rebuild of my DBX not too long ago.
http://www.flickr.com/photos/jeffrot...7610270959790/

The tires should not, of course, be difficult to turn by hand. So I would stop doing that so you don't screw something else up I can't say off hand what would be causing your problems, but it shouldn't be too hard to find out.

Suggestions, take them or leave them:

1- Pull out the center diff by disconnecting the brake linkage and then unscrewing the 4 screws that attach the center diff to the chassis. Check to make sure the output shafts of the center diff rotate freely by hand in opposite directions when turned.

2- With wheels off the ground, rotate the front and rear dogbones or the input cups on the front and rear diffs. Feel if any of these is hard to turn. Make sure that both the front tires and the back tires want to rotate in the correct direction when you turn their inputs.

3- Now you should have it narrowed down to (hopefully) one end of the car. Odds are it is something in your rear diff by the sound of your explanation. Some ideas on what it could be
* Improperly shimmed diff is causing some binding
* Diff inserted "backwards" causing reverse rotation and some binding
* Forign object in the diff
* Some drag in the axle stubs where the wheels mount on

4- Pop off the upper a-arms and remove the dog bones. Check that the wheel rotate freely. Check that the dogbones aren't screwed up in some way (bent, rubbing on something, etc.)

5- Re check the problem diff now that nothing is hooked up to the inputs or outputs. Is it still difficult to turn? If so open up the diff housing. Check for foreign objects, correct direction of installation.

6- If there are no foreign objects and all parts are installed correctly, check the shims on the input gear and the diff output. These set the gear mesh between the input pinion and the ring gear attached to the diff. If you have too many, few, or in the wrong place it can cause drag from a super tight gear mesh or from the input gear or diff from physically rubbing on the diff housing. I am not sure how familiar you are with adjusting these shims. If you want further details don't hesitate to ask, it's not to tough


Or who knows. It could be something else These are the steps I would go through to narrow down where the problem lies. The explanation seems long now that I type it, but it should only take a few minutes with the screw driver.

For what it's worth,
Spiro