Steel transmision gears and gear cover ventilation

[jus-heli-pilot]

Ive just fitted a set of steel transmission gears to my MT . I'm not sure if i need to ventilate the gear cover for cooling, The plastic gears didn't last 1/2 a tank before they melted , this is my first RC car guys any help about ventilating the gear cover would be would be great

 

[iwik76]

Defo vent the gear cover.. the heat generated will not do your bearings any good. Some guy's run without the cover at all but that'll depend on what terrain you roll on.. but moral of story... Vent..

 

[mp3jeep]

What color were your stock gears? I'm just curious.....

 

[jus-heli-pilot]

The stock gears were white, 25, 35, 25, 25 was the tooth sets on the gears I replaced them with same ratio gears.

 

[igetbombed]

I find the plastic gear thing amazing. I have had no problems whatsoever with mine, but keep in mind I got my truck only a few short months ago and it has been cold as hell here in the northeast ever since. I haven't even vented my gears


I'm wondering if they are more prone to melting during warm weather?


@jus-heli-pilot - how hot was it outside when you were running out of curiousity?

 

[lightning73]

There are definately many different theories out there as to why it is that some peoples plastic gears are melting and some arent. In my particular case I fall into the group of people who had problems with them melting right off the batt unfortunately.


As far as why this issue happens to some and not others? In my opinion it is a heat issue yes. But I think the excessive heat thats causing these problems is due to the fact that some of us have binding issues in the drivetrain from day one of new ownership and others luckily will not have this problem. As always venting the gear cover will help in several ways, but I think for the most part its kind of a "luck of the draw" situation for new owners as to wether or not the factory built the drivetrain true or not.


It seems its only after people become more familiar with their Rampage and ask questions on the forum here that they figure these issues out and get them sorted from there. A big reason why this forum is so helpfull....

 

[Zapped]

I was having that problem of stripping gears and decided to grease them,since I did that, I have not stripped any so far.

 

[DemonRC]

This may shed some light on the situation. During my initial testing with the timing belts we looked at all different types of materials for the pulleys. Nylon was the most common plastic used on timing pulleys but a handful of engineers I talked to at Gates and several other US pulley manufacturers all agreed that plastic pulleys can handle the load but the plastic cannot have an RPM above 7k-10k when they are reaching their max load capacity. That was their cap before the pulley failed to to RPM. I would assume that the same physics that cause nylon timing belt pulleys to fail would also apply to plastic gears.


If anybody wants to find out for sure, contact some gear manufacturers (www.rushgears.com for example) and ask them what the maximum RPM range for a nylon Mod 1.5 29-31 tooth gear is under load. I bet the answer will be in the 4 digit range.

 

[jus-heli-pilot]

@jus-heli-pilot - how hot was it outside when you were running out of curiousity?


The temperature would have been about 30 deg C or 86-87 deg F so it was quite warm but about normal for an Australian summer