I think the tranny was made to be a more light weight speed part for the slash, running a huge power system with moster truck tires with a light weight tranny is asking for issues IMO, especially with a tight slipper

I broke a couple of teeth off of the idler gear in my proline trans. Today. After 4 packs thru it. I'm glad that proline made it to were the stock idler will fit in it, because thats the only saving grace for this transmission to make it on the market.The slipper was set from factory and even if u tighen it down all the way down(like all racers have it on their 2wd trucks) it shouldnt strip out the idler.Its hard to find a good plastic idler that will hold up in this application.Replaced it with the traxxas idler. The slipper really makes ugly a noise when it slips.
Other than I couldn't get my pinions to stay on ( never had that problem before)
The transmission has potential with its sealed diff.

If you read the Pro-Line and other reviews the Transmission has all metal gears except the idler, at this point you have replaced it with the metal Traxxas idler so you should be good to go... Watch your adjustments

Good Luck

I have a proline proformance transmission on my rusty for about a month now and all I do is bash and bash hard mainly because there is only 1 track any where near me and it a about 50 miles away. also no bmx tracks nothing. so construction sites parks and the street any I beat the you know what our of my rusty, and the proline ( 86 / 19 or 23 and 9.6v venom 5000mah) and it's been stellar is strong fast and quiet. For what it's worth that's my 2 cents.