Gear materials compatability

[John Ramsay]

A guy at the local track recommended that I replace the nylon gears with metal ones (see picture) . I can only find metal replacements for the small  gears on the end of the main drive shaft not the main nylon one in the diffs.  Would a metal main drive shaft gear damage the nylon one in the diff? Can I safely run with gears made from different materials? 

[Nitroholic]

The first question to ask yourself here is WHY are you replacing the gears.

 

Have you had any failures of the nylon gears, or are you planning to put a MUCH spicier motor in and preparing it for more power?

 

Now, when it comes to mixing materials, it'#s pretty common to have plastic spur gears driven by a metal pinion gear. Doesn;t cause any issues, but will mean the part that wears is the plastic bit...and in the event of any stress loading, the metal gear will eat the plastic one.

 

If it was my car, I would repace the diffs with metal if I could, and fit metal ring and pinion gears in tehre if they exist. The pinion gear could be metal ( but don;t buy cheap ones.... as poorly manufactured pinions will damage the spur) Last on the list would be the spur gear.

 

BUT....unless I was able to do it properly and upgrade the diffs, and if it was holding together just fine without.....then I would leave it be. Get some decent grease in the diff cases, and let it be.

[John Ramsay]

Thank you for the very fast, comprehensive and really useful reply. :)