Revo diff problems ? - RC-Monster Forums

**Revo diff problems ? -** 06.03.2007, 03:35 PM

Hi.

I have just converted my revo to brushless and have done some test runs with it and today i notice a cracking sound from it and found that the rear diff was broken :( Installed a new one and now i think the front diff is cracking to ! How you guys make your diffs to hold up ?

My setup:

Hv-maxx 6.5
GP 3300 14 cells

// Magnus

jnev · 06.03.2007, 04:07 PM

You can buy these: http://www.rc-monster.com/proddetail...rod=rcmflmrvdf which take 1/8 scale diffs and will be very, very strong.

BrianG · 06.03.2007, 05:31 PM

It depends on what was broken. Was it the ring/pinion gear, or the spider gears?

Broken rung/pinion gears usually means that the pinion was not shimmed for exact mesh.

Broken spider gears is usually caused by a flexing diff cup. When the diff cup flexes, the spider gears can hop teeth which wears/breaks them quickly.

Of course, the stock diffs will wear over time since they only use two spider gears, but if you can't or don't want to pony up that amount of cash for new diffs, you can get lots more life out of stock diffs by getting an Almunim diff cup. This will help reduce the flex in the cup and will make the spiders last longer. Whatever you get, you should also make sure the pinion/ring gears have perfect mesh by shimming the pinion.

06.04.2007, 04:56 PM

Quote:

Originally Posted by BrianG

It depends on what was broken. Was it the ring/pinion gear, or the spider gears?

Broken rung/pinion gears usually means that the pinion was not shimmed for exact mesh.

Broken spider gears is usually caused by a flexing diff cup. When the diff cup flexes, the spider gears can hop teeth which wears/breaks them quickly.

Of course, the stock diffs will wear over time since they only use two spider gears, but if you can't or don't want to pony up that amount of cash for new diffs, you can get lots more life out of stock diffs by getting an Almunim diff cup. This will help reduce the flex in the cup and will make the spiders last longer. Whatever you get, you should also make sure the pinion/ring gears have perfect mesh by shimming the pinion.

OK thank you for the tip about alu cups. You know where i can buy any good ones ?? Btw its the spiders that are broken.

gasshead · 06.04.2007, 12:01 AM

is this a common problem with the Bl revos? i never broke a gear with my nitro except for spurs

BrianG · 06.04.2007, 12:03 AM

Fairly common, yes. Gotta remember the tremendous amount of instantaneous power available in a brushless system compared to Nitro. BL has max power right away, while Nitro build up to its max power, usually towards the upper end of its RPM range.

gasshead · 06.04.2007, 12:05 AM

ok. i see..but for a raceing app ithe diffs shuld be fine? i will also do some light dutiy pulling

BrianG · 06.04.2007, 12:12 AM

Well, if it's the start torque that breaks them, the best thing to do is ease into the throttle or set the ESC throttle curve if you want to save the diffs. Personally, Al diff cups are a worthwhile investment for long lasting diffs if you don't want to spend the $$$ for the 8th scale ones. Racing would probably be more easy on them than pulling will be.

gasshead · 06.04.2007, 12:23 AM

so would the ones offered by maximizer be a worthwile investment?

Serum · 06.04.2007, 01:27 AM

Yes, among with aluminum housings. but if you want a set and forget diff and you can swing it; pick the 1/8th diffs.

gasshead · 07:16 AM

i personally dont want a set and forget diff. i really enjoy tearing my trucks down more than i do driving them. it might take a while to get them up and running again but most of the time they get really clean and in better working order than they were in.

i also beleve i will be adding the maximizers to my list of parts. they are made of hardend steel, maby a little more rotational mass to deal with but its worth it in the long run. not a bad price also 37 bux for one...

MetalMan · 06.04.2007, 09:36 AM

I guess I have been lucky, since I've never taken the diffs apart on my Revo. Perhaps the center diff + slipper clutch helps? :) That's on 5s2p A123, Feigao 7XL, Mamba Max ESC.

gasshead · 06.04.2007, 03:03 PM

thats how i have been with my nitro stuff....but i'm excited to find the weak spots on the truck when i go BL

Serum · 06.04.2007, 04:29 PM

Quote:

i personally dont want a set and forget diff. i really enjoy tearing my trucks down more than i do driving them.

I suggest to stick to stock diffs then..

crazyjr · 06.04.2007, 04:39 PM

I just ordered a set of the 1/8 diffs, I just cruched the rear diff ( both upgraded to integy cups and cases ) with a 9XL quark 125 and 5s