i was wondering the same thing myself.. I have not had any problems with that aspect of the mod... mine is twisting the t-maxx axles due to the power of the os 18 I run.. I did replace the diff housings front and rear with new ones because they were worn, not broken and were about a year old... about 2 gallons thru them... You could drill a hole in them if you want, but i doubt it would be straight.. just don't see the need for it.. works fine