First time with a brushless car...

[Dave145]

Okay let me see if I can give you a detailed description of my problem here... I melted my differential gear. I have the new Castle Creations SCT system in my goldpan with a stealth transmission (yes I know it's overkill). I chose this system because my car is rather heavy (4.25 lbs) due to my custom aluminum front and rear bulkheads (they're both about 1/4 of an inch thick and I kept breaking the carbon fiber ones). Anyway I ended up melting my diff gear somehow. I did this once with my RC10B2 as well on a brushed setup due to the diff being too loose. This diff is tightened correctly but it still melted. If my memory serves me right, I thought I remembered seeing a post somewhere on here that someone had aluminum diff gears for this transmission. My stealth is the first generation edition with the 2.25:1 ratio. Can anyone tell me why my diff melted (I would assume because of too much wheelspin because of too much power) and where to get these aluminum diff gears? I'd also like to upgrade my idler to an aluminum one as well if that's possible. Does anyone know where I can get either of these?

[GoldRush]

i would say excessive wheel spin causeing the diff gear to overheat and yes thats alot of system for that trans i think...as far as the gear i remember seing it before too but im not sure they are available/made anymore...i belive it was robinson racing or mip that did the gear.

[JK Racing]

cant help you with the alloy gears, but 2 words...slipper clutch, let it spin and save the rest of the tranny from getting toasted

[Dave145]

good point with the clutch. I do have it set somewhat tight but it still spins quite a bit during hard turns. I did notice that the car does spin out ALOT though, especially on pavement. Any ideas there as well? I thought that meant the diff was too tight.

[JK Racing]

sounds more like tires/shock set up if you are spinning out on pavement. the slipper "slips" during hard turns? it should only slip during hard acceleration. If your inside rear tire is lifting up and spinning twice the speed of the outside tire, you are "diffing out" and that would melt your diff pretty quickly.

you should try to find a milder motor, but still big KV. That 4 pole motor is just a monster in anything, let alone a 20 year old goldie.

[Dave145]

Ha ha you're right about that... I just like the "punch" it gives. Now after some work with my close partner google, i found a site saying that this evader diff might work as a gear diff. Any thoughts?

Evader Diff:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXSXA9&P=7

[socal jared]

Make sure you dont have any bind in the case. its common for people to over tighten the case to the motor mount creating bind then heat. Was your motor/esc over heating?

[JK Racing]

how many teeth is it (needs to match) and this doesnt bode well (metric bearings?)

One Factory Assembled Diff Gear with 10x15mm brass bushings

[JK Racing]

oh, and dumb question,

running bearings? or bronze bushings?

[Dave145]

Re-done bearings with full lubrication and tuning (you know...the works and stuff. ) Tranny was fine and spun almost like new. I DO have my graphite shelf queen with a stealth tranny that rolls ALOT more freely both forward and with the just the diff turning and it's got NO oil in it and hasnt been cleaned or run in almost 2 years. What's up with that? A dirty transmission spinning better than a clean and oiled transmission? I don;t get it but I can't bring myself to swap it to my goldpan (nothing like the "it's on my shelf queen so it's not going anywhere" logic). Anywho, the tranny was free with full bearings in it. Anyone have any experience with that gear diff? I'll post a link to the forum I found it on.

Forum:
http://www.ultimaterc.com/forums/showthread.php?p=1096236

they say any 45 tooth diff should work with little to no mods. Besides dumping $10 on it (I know it's a huge expenditure ), any ideas? I'm used to only rebuilding my transmissions once a month, so this ball diff that seems to need maintenance every few runs is kind of irritating.


Here's a dumb thought: My buddy and I just rebuilt a transmission for a slash a few weeks back and then wrecked the truck (the tranny is still good). Who thinks that that transmission would fit with some mods? I like a challenge, but would that just be ridiculous or better yet just flat out stupid??

[Dave145]

Oh I almost forgot; @ socal jared: no the esc and motor weren't overheating at all and neither was my battery (Traxxas 7 cell nimh) after about 5 minutes of hard racing on pavement. It was unbelievably cool even with a gear ratio of 25:87 on it and just the stock fan on the esc with nothing on the motor.

[Dave145]

Never mind about the slash tranny... it's definitely not going to work due especially to those rear arm mounts being molded to the tranny case. Anyway, any ideas on that evader diff I posted above? $10 seems like one heck of a deal to get my car out on the road with a better diff (I've always favored the gear diffs for some reason)

[JK Racing]

nothing stopping you to try it out for us

[slapshot1979]

Re-done bearings with full lubrication and tuning (you know...the works and stuff. ) Tranny was fine and spun almost like new. tranny that rolls ALOT more freely both forward and with the just the diff turning and it's got NO oil in it and hasnt been cleaned or run in almost 2 years. What's up with that? A dirty transmission spinning better than a clean and oiled transmission?

I dont run hardly any lubrication inside my transmissions maybe a small dollop of grease on gear faces but thats about it. doesnt need it.
sounds to me like your diffing out by having the inside tire lift and spinning to fast compared to other side. or are you blasting crazt donuts?? they look cool but will smoke a diff in seconds with brushless.
Not much has changed for transmission design since the stealth ..input shaft-idler gear-diff gear. I think any transmision should hold up to resonable use and properly setup with brushless.

[Phin]

Evader diff gear won't work in a 2.25 stealth trans cause it's 48t and not 45t.