XRAY - Model racing cars

I am having trouble getting the proper gear mesh between the small bevel drive gear that attaches to the drive shaft and the main bevel gear in the rear transmission. There is just a very slight bind in the rear tranny when you turn the rear outdrives and it makes a little bit of noise. I have taken the rear transmission housing apart four times, an I can't figure this out. I checked and re-checked the width of the tranny assembly (from outside of bearing to outside of bearing, and that was ok. I have no gap between the end of the driveshaft and the bearing on the outside of the tranny case. Should I be concerened about this, or will it wear itself after a few runs?

"There is just a very slight bind in the rear tranny when you turn the rear outdrives and it makes a little bit of noise."(mekong)

If its new parts, then all you are hearing is the gears stepping together. If it turns, then stops itself on a high spot, then I would take a close look at the gears, diff case. ect. Make sure you are not putting to much torque on the assembly screws, run them down tight, then just a bit more. (use good judgement).

Double check your assembly steps, ( I know you have done that already, stay on the safe side). I think its just new parts (if they are new) and they should wear in.

One thing I do when I rebuild a diff (complete, in the diff housing) is to spin it with a drill using a cutoff dogbone I have. I look ,listen, grab each outdrive as it is spinning slowly and feel the gears stepping, making sure it is operating as it should. If I hear a severe noise or feel some serious vibration, I go back in and double check everything.

Some people break in their diffs this way before they ever put them In the buggy.

Hmmmm,

I've always just assembled the diffs per the instructions and dropped them in my buggy. The fit and finish on XRAY parts are so good, there should be non need for any type of "hand-fitting".

I would definitely recheck your assembly, don't overfill the diff, and make sure there is only one gasket on the main gear.

I have just started assy of the Tq and found exactly the same problem! spent most of the night trying to find the rouge tooth..
Poss a slight miss match in the stamping of the gear. Least you know its not a uniqe problem and should clear up after running in.

You might have the problem I had, when I assembled my TQ.

The rear diff housing, that holds the bearings in place was machined incorrectly. It allowed the differential to droop, and cause bad mesh between the shaft coming from the center dif, to the teeth on the differential.

I contacted my local hobby store, and I was sent a new rear diff housing. That solved the problem, and Ive had no issue since.

But the symptoms are exactly as described, sometimes it would turn freely... other times it would grind, and sometimes stop and bind up.

Thanks Rosco. Spent ages with a kneedle file yesterday on the diff teeth. Only to find the problem still remained Ill be looking for another diff housing now.