I was reading on one18th.com about some fellas fooling around and putting the ball diffs from an associated RC-18t in their m18's. Well, im here to tell ya: It works like a charm! Really, I've been trying for some time to get a hold of an Xray ball diff. Everyone's either a) out of stock, or b) OUT OF THEIR MINDS!!!!!!!!$35BUCKS OR MORE??????????
I have heard that the xray is much smoother... I'd still buy a set once i go brushless... but guys, believe me when i tell you this:
2 rc18t diffs cost about 18 bucks, and out of every doo-dad i've ever put on my m-18 over the past year and a half (almost) THIS IS WITHOUT A DOUBT THE BEST PERFORMANCE UPGRADE I'VE MADE.
Just build the diff like in the manual for the 18t (i looked up the .pdf on their website) and use a small peice of heat shrink to shim the bearing on the short side of the diff so that it presses the bevel gear against the bevel pinion... their bearings sit a little bit closer than ours. The outdrives fit our u-joints, bearings etc. purrrrrrrrrrfectly. It's super quiet........ the handling is SO MUCH BETTER than with my stock diffs even AFTER i 'worked them over'...the big block works much better with this type. One last benefit: our bevel gear is 36T, theirs 35, so it 'underdrives' the axles...shorter geraing=more pickup on the track. It's the same reason we use the 42t spur.
I love the xray product, but 18$ vs.70$ or more??? You know the answer