Quote:
Originally Posted by Russ Noble  Tirebiter,
I have been looking for information on the 'drop through' test for the case bearings on 930's. Specifically measurements for the mandrel that is used, or maybe buy one from a retired Porsche mechanic?
Cheers |
The "drop through" gauge is pictured below. This is used to check the O.D. on the needle bearings that ride on the input and pinion shafts. They are
not used on the bearings pressed into the case.
The measurement at the top is 43.80mm; the measurement on the bottom of the taper is 43.40mm. This puppy is
very temperature sensitive and should be used between 64*F to 80*F. It has four tapped holes to insert bolts to keep it from gaining heat from the surface it might be sitting on. I use s
tyrofoam. Just for grins I took a known good bearing and let the gauge heat in the sun untill it reached 100*F. Zoom, it passed right through.
There is also a drop gauge used to check the I.D. on the needle cage bearings but it's a joke. Gentle pressure on the inside of the bearing will pop out any needle held by a weak cage.
Both gauges and the 385 tool are pictured also.
DC