Revolution Design B74 48P Machined Spur Gear (Center-Differential) (72T)
About this part
- Direct fit to the B74 center differential
- Usable with the standard composite Team Associated and Revolution Design’s aluminum center differential case
- Available for stock and modified motor gearing
- Machined from high-quality Delrin material
- Precision-machined for highest possible precision
- 72T and 78T sizes available
Reviews3.6 · 5 reviewsacross all options
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.
Well machined piece. I just set this up in my B74 truck conversion. Its perhaps the most true, Plastic spur gear I've encountered in RC. The machining is very clean and setting the mesh was very easy. Time will tell how it holds up but I'd bet at least as well as the stock, probably better.
Reviews are mixed for the Revolution Design B74 48P Machined Spur Gear (78T variant). Several reviewers praise the clean machining, true running and easy mesh setup, and report good durability, including one who ran it at high speed and another who got two racing seasons out of it. Two reviewers report poor fit: one found the centre bore oversized so the gear relies on the mounting screws for centring, causing misalignment through rotation, and another found the spurs oblong and unable to achieve a good mesh. One reviewer reports failure after mounting screws loosened and disturbed the mesh. Overall, reviewers disagree on fit quality, with positive experiences and fit complaints both appearing across the sample.
- + Clean, precise machining
- + Easy gear mesh setup
- + Durable in racing and high-speed use
- − Oversized centre bore relies on screws for centring
- − Spurs reported oblong, poor mesh
- − Mesh disturbed when motor mount screws loosen