First outing with my son and the Durga ended with two broken diffs

[built2scale]

Well, as my title stated, our first bash in a parking didn't end on a good note. Found both front and rear diff pulleys torn apart.

Much like this person's pics,
http://www.oople.com/forums/showthread.php?t=20313

So what should I do now? I've read bits here and there about using a 501x diff but I don't know what parts I would need. Is there a complete set to buy or bits and pieces?

Everything else looks good so if I keep with the Durga instructions, it looks like I just need the two 37T pulleys. What do I need if I want to upgrade to the 501x diff? Just slap in a 501x pulley or is it more complex than that?

[jimmy]

I've personally (mentioning no names) rebuilt a diff like this for someone - there was no glue on the diff rings and no grease on the diff balls. I'm of course not saying that you didn't build the diffs as per instructions but blowing 2 diffs simply shouldn't happen.

I'd have thought the diffs slipping would cause this - but the one I rebuilt was down to the rings slipping on the plastic holders from what I could see.

As long as the diff rings and balls are still in good condition then you'll just have to replace the pulleys. If you're using the original stuff then pay close-close attention to the build steps, degrease and glue the rings with some sort of flexible strong glue would be best.

The 501X diff halves work on the metal-metal friction - which should stop the diff rings spinning, and it should only really be needed on the rear as the front won't have enough torque to threaten the Durga diffs if built correctly.

If this was genuinely your first time out with the car then be aware you'll have to keep checking the differentials as they bed in - since they can loosen slightly and begin to slip, which could also have been the cause.

Let us know if you need any help - the Durga is a great car

[Spihc]

This confuses me alot.

First I read that (if I use a high power motor) need to replace the rear diff halves to 501x dif halves.

Later I read that the only thing needed to replace is the diff pulley...

It might be that english is'nt my mother tounge but I really get confused with all this.

[jimmy]

I was replying regarding fixing these broken diffs - which might not have anything to do with 'powerful motors' at all. If you build them well even the stock diffs should handle most abuse you can throw at them - the 501X diff is definitely a good idea if you're racing.

[built2scale]

Thanks Jimmy, it was our first time out with the car. I think I did build the diffs correctly but can't be sure as the Durga is only my 2nd time building a RC car and the 1st time was over 25 years ago!

I will probably get new Durga pulleys then and watch my build more closely. I am running a Novak Havoc BL on this and I remember the last thing before the car was not responsive and it was when it hit a large pothole at a high speed. Maybe that put the jolt and cracked the diffs? I don't know, next time I'll make sure the parking lot is clear of pot holes.

[DCM]

the issue with the stock diffs, is having to rely on the glue to hold the plate in place. Once the glue goes, it slips, and no matter how much you tighten the diff, it still slips under load, heats up the diff and eventually melts the pulley. This usually happens on the rear diff, as it takes most load.