Why Would A Twin Detonator Diff Suddenly Lock

[taliesin]

my rear gearbox has gone suddenly crunchy. i took it apart, noticed nothing irregular, put it back together and now the diff is locked. i did not rebuild the diff gear, just inspected, cleaned and lubed the rest of the gears. no sign of abnormal wear on the rest of the gear set.

i know i'm asking for a guess here, but do you think the metal bevel gears just broke inside the diff? is that even possible? will it hurt anything?

there's more resistance now, but otherwise it runs ok under power. is this normal for a locked diff to be stiffer when you just work the wheels by hand?

i kinda like the locked rear diff, but just want to know if i'm destroying the rear gearbox by leaving it alone for now? [or maybe i have already done it in]

its not a big deal if i trashed it, the gears are available for not much money, but i'm just wondering what the heck happened. spontaneous diff locking? breakage? freak occurance?

[B.M.T.]

What you will probably find is one or more of the legs have snapped off the little 3 legged spider, and the wee bevel gears are turning sideways inside the diff center.

They do do that, apparently.

[taliesin]

i just ran a pack through it and it goes ok with a locked rear end. i don't know if i'm trashing anything or not.

its definitely more fun this way, but i do notice a bit less run time on the battery pack. i'm guessing it won't ruin anything, since guys lock the diff intentionally all the time on other models. is this a reasonable assumption?

[Woolfy]

i just ran a pack through it and it goes ok with a locked rear end. i don't know if i'm trashing anything or not.

its definitely more fun this way, but i do notice a bit less run time on the battery pack. i'm guessing it won't ruin anything, since guys lock the diff intentionally all the time on other models. is this a reasonable assumption?

You'll be fine running it with a locked rear diff, but you will lose some handling at speed on get grip surfaces. However, if the spider has broken in the diff, make sure that no small bits of metal can get out of the diff housing and into the plastic gears as this will ruin the rest of your gears very quickly!