ARRMA 4x2 BOOST locked diff???

[acpowell]

I was trying to help a friend with his Senton and noticed his diffs seemed locked. he stated that they worked before and that he just replaced the rear diff. The box he showed me was one of the ARRMA 4x2 BOOST kits. When I took the diff apart it looks like it was built to be locked. The gears mesh in such a way that they don't seem to turn freely.

Is something not right or is this supposed to be a locked diff?

 

[Dan B.]

I was trying to help a friend with his Senton and noticed his diffs seemed locked. he stated that they worked before and that he just replaced the rear diff. The box he showed me was one of the ARRMA 4x2 BOOST kits. When I took the diff apart it looks like it was built to be locked. The gears mesh in such a way that they don't seem to turn freely.

Is something not right or is this supposed to be a locked diff?

I’m sorry I don’t know the answer to this, I’m sure someone else with experience in the 4x2’s will chime in. I just wanted to say welcome to the forum!

 

[acpowell]

I actually think I know what is wrong. I believe it was shimmed improperly from the factory. He just told me that it was preassembled and when I took it apart I noticed the center bearing was destroyed and if you pull the axles out when assembled it actually performs as expected. It seems like there is a shim that should be in there somewhere and with the tolerances so tight the smaller gears are sliding on the shaft and binding with the center gear.

 

[acpowell]

I figured it out. After replacing the bearing and removing the tiny balls from the blown bearing it is working now.