Summit Front Diff problem?

[jpoprock]

Does anyone here have a Summit?

I posted this in the Traxxas forum, but this is my preferred place to hang, so I thought I'd ask...
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Hey guys! I took the kids sledding yesterday, and while the old man was taking a break from walking up and down the GIANT hill, I decided to drive my Summit around in the snow. I. HAD. A. BLAST!!!! Wow, was that fun. I never thought that driving up snow drifts, trying to get over them, would be so fun. It's because of the challenge of it. If you work at it, you can get that thing thru almost anything if yer patient. UNLESS the wheels bury themselves in deep snow, then it won't come out.

Anyway... I really worked the low/high settings, and the front/rear diff locks. Just to get the hang of it, and SEE what the results were. The truck ran and drove great. But when I put it away for the day, I brushed up against one of the front wheels, and it spun freely. THAT shouldn't be should it?? I checked the others, and they don't spin without spinning another tire (as a 4WD should!). But my front left tire spins free, the drive shaft and all. And I didn't hear any clicking in the diff either. So, the wheel and drive shaft spin great, but then once it gets to the diff, I can't see what's going on. But it has to mean something inside the diff is no longer meshing right??

So, I'm sorta stumped as to what this might be. I don't want to take it all apart for nothing, so if you have any advice on where to look, that would be great.

Thanks!
J

[suicideneil]

Might have sheered the little drive pin that holds the spider gear in place/ onto that shaft inside the actual diff cup. Only way to be 100% is to dismantle that half of the truck and crack open the diff- not much fun with all those linkages allover the place, but no other options.

1/10 loking diffs isnt the best idea ever by traxxas, they are weak to start with compared to 1/8 diffs, then add a heavy truck into the mix + complicated locking mechs and its bound to fail sooner or later..

[Arct1k]

Or the actual pin on the plastic outdrive...

[jpoprock]

Good call! I bet that is it because the diff isn't clicking like a blown spider gear. I'll have to just take a look then! I'll report back...

I love the truck, but I've always known that the diff's have to be the weak link for sure. Way too much going on.

[shaunjohnson]

sometimes the diffs seize up like mine did.

[jpoprock]

Well, I pulled the diff, and found that the output pinion on that side had sheared itself in half somehow. The pin was fine, and all the gears were fine, but that shaft broke in two.

I thought I had heard something about Traxxas having a bad batch of those out of the factory. And I thought the dude I bought it from had them break and Traxxas replaced them.

That makes me wonder if the replacement batch he got was still from the bad batch? And there is no way for me to know if the replacement I order is from the bad batch either? Too bad there isn't a beefier RCM set to buy. I'm pretty sure that you can't just install a 1/8 diff unless it was designed just like the Traxxas one, which isn't likely to happen. If the part is cheap, I'll just order several.

But boy getting to that front diff is a PITA!!

J