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Amazing
25-12-2009, 09:49 AM
Hi, i got my son the Mad Rat for Xmas and it run for 10 minutes and then stopped. The wheels wont turn and makes a high pitched noise'. i am not sure if it is the engine or gear box. i was running it in some sand before and then on pavement.

any ideas ?

rob84
25-12-2009, 10:01 AM
Sounds like there could be sand in the diff or the pinion has striped the main gear. your best of taking the diff apart and trying to rebuild it.

jon kedge
25-12-2009, 10:11 AM
Hi there,try this, it might be the slipper clutch which is on the spur gear,it works like a clutch that stops the wheels wheelspinning but can also be to slack and cause no drive at all,check your instructions and it might tell you how to check and maintain the clutch,what we do is this,,remove the gear box cover and with yiour thumb whilst holding the rear wheels between your kness try and turn the large spur gear,if it turns easily without any resistance then tighten the clutch nut 1/4 turn and check again ,keep doing this until its doesn't slip ,do not over tighten or you will damage the gears,the idea of a clutch is to stop wheelspin when you hit the throttle and you should get around 2-3 feet of slip under full acceleration, if that doesn't work take the motor pinion off and see if the gearbox rotates freely and also the the motor rotates freely,hope this helps.

Dazzler
25-12-2009, 10:39 AM
Could just be a loose pinion - check the grub screw is tight and screwed down on the flat of the motor shaft. Good luck sorting this out.

jim76
25-12-2009, 09:45 PM
also, as a tip, don't drive it on sand! sand will ruin the car very quickly as it get in all the joints and gears and tears them to pieces in no time. Stick to tarmac and grass where possible.

bigred5765
26-12-2009, 10:46 AM
Hi, i got my son the Mad Rat for Xmas and it run for 10 minutes and then stopped. The wheels wont turn and makes a high pitched noise'. i am not sure if it is the engine or gear box. i was running it in some sand before and then on pavement.

any ideas ?

i thought from this bit that you might be running a brushless system in there??/ if so check the sensor wire,

Amazing
26-12-2009, 02:32 PM
it looks like i have to take it apart. the diff is fine but there is no drive in wheels. i can;t get the gear box off as there is a threaded screw.