XRAY - Model racing cars

My original crown gear blew so I order a new one to replace it. I install the new one and it binds #@$@#$@#.

Take a look at the pick ( can you find waldo?)

I have mine shimmed so that the mesh is a bit tighter then with out the shims. You may want to shim behind the bearing of the side with the crown gear to open up the gap between it and the bevel gear.

Is this on the XB8EC?

If so I am not sure why your would bind and mine wouldnt if they are the same cars. Maybe check to see that you have all 4 screws down tight and its not tilted causing the bind.

The fact that you had a gear blow up on you means to me that there is some other issue in your setup. Unless that mesh was never correct to begin with and you just wore the other crown gear in until it didnt bind as bad then it broke from becoming weak.

Do you grease these gears? If not you should for sure have some grease on them.

I noticed the same on Mine but I just said that I'd stick with it. Its only the 1 tooth on my front diff. Just took it as its my luck this is.

I use Mobil 1 on many places and the diff gears is one of them. I find no dirt at all in there even runing on a dusty track so it must be a close fit to the chassis.

The reason to grease bearings is to allow the grease to hold the dirt that gets past the seals and this allows the balls to still roll freely and not bind from dirt. The grease may attract dirt but it also acts as a dirt holder as to allow lubrication to the gear but still repel the dirt from sticking to the gears. If you throw dirt on the gear and blow it off you will still see that some is left behind but with grease on them it pulls the dirt in and away from the where the gears mesh yet still leaves some amount of lubrication to the metal.

It works for me and I have no signs of wear on my gears so far. My CB and Spur gear gets some bicycle chain lube/wax that dries up but still protects the gears. However I must admitt I break down, clean, grease, oil, loctite, and look over my car after every track day. I imagine if I left my diffs alone for a gallon they would look nasty and risk failures or aid in excessive wear. My diffs and shocks get rebuilt every other race but the outer gears are cleaned and greased every race.