HPI 8k clutch quirk

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Chief409

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I noticed, since the drivetrain is apart right now, with the drive belt off, that since the humidity increased the clutch is now dragging slightly in the bell, before the clutch would spin freely. Nothing else, just the humidity has changed, with the buggy sitting on the bench in the air conditioning.


Has anyone else encountered this?
 
That and/or debris holding shoes from full retracting...perhaps a bearing?

I wouldn't think thermal contraction would be great enough to cause it to drag.
 
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It's entirely possible the clutch pads may have absorbed moisture and swelled a little. But I would expect humidity would have to be very high with a significant exposure time.

To check this happened, you could place the clutch in an oven at 150 C for a few hours, then fit it again and check for drag.

Probably best to replace it if this has happened anyway, they're cheap enough.
 
It's a new clutch with only a couple runs. It struck me as strange that just sitting on the bench now there's some drag, two days ago it spun like a top. Only thing that changed is the humidity, we've been getting monsoon weather, even had som rain. Never heard of a clutch absorbing moisture and swelling before, sitting stationary on the bench, thought I'd check and see if anyone else had.

Might pull the clutch off and dress it with a sanding block today, can't hurt.
 
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Neither will the oven, worth checking it out. Being a fibrous pad, its possible moisture could be absorbed.

Its possible the pads may be softened a bit, sanding will fix the problem, but it might not last long. Pick up a spare just in case and good luck man.
 
RCDAD said:
I'd go give it a good run. I bet it would go away.
Click to expand...
I'd love to do this, but I'll be pulling the engine to get the rear driveshaft reconnected (last time I left the engine in, more difficult) after the new center diff gears get in, so a couple minutes of work is all I'm looking at.
 
Update. The humidity has been going down and I'm not noticing as much drag.

Guess this means, "Stay Away From The Water" with this clutch. It's the third clutch I've used, the original which I replaced when I went to the belt drive and the V1 bell (and needed replacement, big groves in both the clutch and bell), a OEM 6k clutch, and the HPI 8k. The HPI clutch is made of different material then the OEM, seems softer and is thicker.
 
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