Revolution Design B74 48P Machined Spur Gear (Center-Differential) (72T)

I didn't have a problem with my mesh at all still going strong my b74.1d is going 70+ mph! So there's your answer highly recommend over the stock ones I have stripped out 2 of the stock ones just from braking at high speeds and forgetting to set the epa on my remote... My fault though, so I tried this, so far so good I ran it at full speed and it held!

Eh, really not that great, the main issue is the center diameter, it's too big, the original spur is much tighter so that the centering relies on the center bore and hub of the diff case, not the screws holding it. I bought 2 and both are like that.

Those spurs are maybe 0.002-0.003'' too big in the center to have a tight fit, so the centering relies mostly on the screws. Kinda like installing aftermarket wheels on a full-size car without the proper centering hub rings.

You have an obvious misalignment when you rotate the spur with the diff in the car, so the gear mesh will vary throughout the rotation.

They work, but really nothing special sadly, ''German design'' proudly displayed on the packaging, but I think they may need a GD&T class. I expected a very close to perfect true cocentric spur at that price and with that flashy packaging.

Lasted to two seasons of racing. finally failed when the screws holding the motor mount came loose from the chassis and messed up the gear mesh

I bought two and both are impossible to get a good gear mesh. Both spurs are oblong.