Big Rock Rear Arrma problems

[Jimmer101]

Hi there

My big rock is making funny clunky noises coming from rear.

Any ideas please ?

Thank you so much

James

 

[GraniteFox]

Could be a number of things. Busted teeth on the spur gear or blown rear diff. Easy to pull the power module and check. Also check to see if your motor mount plate is bent. Once you have the power module off rotate the rear diff and check for any binding or grinding. Good to keep a spare diff and a spare spur gear in your spares. Fairly inexpensive.

 

[Jimmer101]

Could be a number of things. Busted teeth on the spur gear or blown rear diff. Easy to pull the power module and check. Also check to see if your motor mount plate is bent. Once you have the power module off rotate the rear diff and check for any binding or grinding. Good to keep a spare diff and a spare spur gear in your spares. Fairly inexpensive.

Thank you granite fox will check

 

[quiznatodd bidness]

Yep. I would guess input gear on the rear diff has a few shaved teeth. The rest of the gear will be the same in a few minutes of running.

 

[Jimmer101]

Thanks again guys for advice. It was the input gear. Has anyone tried a metal crown and metal input gear as below ?

I already have a metal slipper in my power module so any future impacts would go directly to motor / ESC I spose ?

https://www.ebay.co.uk/itm/36410793...ar=633469292695&widget_ver=artemis&media=COPY

Thanks again

Simon

 

[Kennydvorak1984]

I've actually had a very similar situation on mine and I was stumped for a while, but it was the plastic center drive shaft, the splines on the motor end of the shaft were stretched out. Hope this helps someone

 

[quiznatodd bidness]

Thanks again guys for advice. It was the input gear. Has anyone tried a metal crown and metal input gear as below ?

I already have a metal slipper in my power module so any future impacts would go directly to motor / ESC I spose ?

https://www.ebay.co.uk/itm/36410793...ar=633469292695&widget_ver=artemis&media=COPY

Thanks again

Simon

I’ve seen those listed and was also curious. Cheapest option is probably to either get the whole diff off a 4s outcast/kraton on Jenny’s (inputs are sold separately as a pair) - about $85 total for both diffs, or get the inputs off Jenny’s and just the metal crown gears from amain hobbies.

The motor and esc will only be bothered by heat and dirt wearing out bearings. So the next thing to fail is most likely a rear axle or center driveshaft.