jdlev

Hi Guys,

Having an issue with the rear drive train on my Team Associated rc8.2e 4wd buggy. The front wheels seem to be getting all the power they need while the rear wheels aren't putting down the power, and it's got a pretty good grinding noise coming from the rear? Is there a way to tighten up this connection, or does it sound like I blew my differential pinion gear? Thanks for any tips.

collector1231

My Feedback: (1)

It sounds like you blew something up in the rear diff. Only thing you can do is order a rebuild after taking it out and seeing whats ground up.

jdlev

That's what I did...upon further inspection, I think it blew the center diff....not sure if it was because the dogbones had so much travel before adding some o rings to the center line inputs, but I'd bet that probably had something to do with it. I dunno maybe I'm wrong. I got a couple of pictures of the planetary gears in the main differential. Sure looks to me like the sun gear got shredded

The sun on the left is the one that drove the rear tires, and I think that's why I heard that constant grinding noise. Funny thing is, is there was probably only 5 runs on the thing. Gears shouldn't wear out like that should they? Was there some setting that was dialed in wrong that caused them to wear prematurely?

image by Jeff Brown, on Flickr

image by Jeff Brown, on Flickr

collector1231

My Feedback: (1)

They can grind out like that with too many powerful launches. You might want to loosen the slipper just a little in order to relieve stress on the center diff next time, though.

Neil2704

Any other known problems with this buggy? I just bought one tonight.

jdlev

Well, their customer support has been phenomenal. Just make sure your bolts are all tightened down/have loctite applied. Mine was assembled by some lazy ass that cut every corner they could. I've been paying for it the last few weeks, but I've been speaking with their customer support, and they've sent out any parts that fell off or were damaged due to the poor assembly...

robwiljas

Maybe yours was built on a Monday by someone with a hangover lol.

No loctite is normal, they supposedly quit using it because people complained about not being able to take it apart and stripping the heads of the screws. They also put just a tiny bit of oil in the diffs so it's less likely to leak in the box.

I took mine apart and loctited everything and rebuilt the diffs before ever running it. I do that with any new model.

Collector it doesn't have a slipper, 1/8 buggies and truggies generally don't use them, just a center diff. You can get them though, RC-Monster sells an aftermarket center diff/differential they call the Slipperential .

Maj_Overdrive

My Feedback: (11)

Yeah no slipper on 1/8 buggies. It's a little hard to tell in the pics how bad those gears are but they definitely have a bunch of wear on them. See below for why.

Unless you have a loose or missing grub screw on the center rear driveshaft the reason the front wheels are getting more power is because of the center diff. Just like a front or rear diff the cd (center diff) splits power between the front and rear. RTR's often have the cd filled with grease or a very light silicone oil. The lighter the oil the more the diff will unload and send power to the front tires turning them into pizza cutters. Heavier fluid locks the cd more sending more equal power front and rear. The wear you see on those gears is due to excessive unloading, either from too light a fluid or running with a center driveshaft disconnected for extended periods of time. For a 1/8 brushless buggy I recommend at least 25k fluid, many go as heavy as 100k. Racers who want diff action and are finessing the throttle will go 25k, bashers blasting around at full throttle go 100k. If you're bashing and unsure start with 50k.