[T3] type3-vwtype3.org Digest, Vol 2, Issue 31

[Jim Adney]

On 30 Nov 2010 at 10:02, Tim Keohane wrote:

> The fan blades are located in a venturi/throat/nozzle arrangement.  
> With the fan out I powered the unit and watched the blades as the  
> lower portion of the throat is scuffed/abraded. I can manually move  
> the fan blades ever so slightly (less than .01") and the contact  
> ceases. I suppose the "squeal" could still be the bearings, sounds  
> like bearings, but I suspect the fan starting under load  will be more  
> prone to failure down the road ( because of the contact ). I inverted  
> the fan and started it up and I have no noise. Still could be  
> bearings. A few drops of oil won't hurt.

Interesting. It sounds like something warped slightly over time, but I haven't 
seen that before. If the fan blade was that close at the bottom, how much 
clearance was there at the top? Was there side play in the fan shaft?

Oil will certainly help center the shaft a bit better, but that's only by the 
thickness of the oil film, which I wouldn't expect to be more than a couple 
thousandths. It's still a good thing to do.

Were there any signs that this fan housing had been subjected to unusual forces 
over a long time? Examples could be mis-installed at the top, so that the 
gasket was folded or out of place, or a poorly installed radio that pushed 
against the housing.

-- 
Jim Adney
jadney at vwtype3.org
Madison, WI USA