Kraton Kraton 6S rear wheels slip and whistle

[ManhattanRC]

Took my Kraton 6s for a joyride the other day on punch setting 9 under 6s power. No big collisions, but towards the end of the ride I noticed some whistling and slipping coming from the back wheels. When it's not underweight, obviously the slipping is minimal, but under hard acceleration and wheels to the ground it slips considerably.

Not hearing any grinding, so I'd like to know your thoughts before I do a postmortem review.

As always folks, I appreciate the insight.

 

[Ari33]

Loose grub screw on a coupling in the driveline going to the rear?

 

[ManhattanRC]

That's the first thing I thought of, but that bad boy ain't going nowhere. Unfortunately when I go to take it apart, that screw is going to be a pain in the **s.

Everything responds appropriately when I spin the wheels by hand, it's only under power with the wheels on the ground that the slipping happens. I'm thinking that I might have stripped the main input gear, but there was no grinding to indicate that was happening. Even if I stripped it, I would still be able to turn it by hand and see the wheels respond. Underpower though, I would definitely see issues.

Oh well going to start wrenching.

 

[nino]

Pop the rear diff out and take a look...

 

[NewSensei]

Have you thickened your center diff fluids? With the stock fluid it tends to send all the power to the front under full acceleration... I put silicone ear plugs into mine and no longer see uneven power distribution. Dunno if that would be the problem but it is easier to do than disassembling the back end

 

[Jimbobjr]

punch setting 9 under 6s power

if the difs turn fine than its most like the ring and or input gears.