Phantom Grip info

[Robert Legere]

Mike wrote:

>Basicaly it works by puting a controled bind on the
>spider gears using harded steel blocks and calibrated
>springs.

*****Mike, as you know this is almost exactly the same type of diff. I had
made for Tim Mather's car years ago. We found through experimentation that
we had to increase the preload substantially to get the performance we
wanted, but considering I just replaced the original springs last week and
they were installed in 1995.....it has proven reliable. The springs (machine
die springs) cost all of $3.50 each from McMaster-Carr, and I simply shimmed
them with hardened washers to get the desired preload. The original springs
had settled about .050" each. Anyone can tune the diff this way. I ended up
with 1640 lbs of tension (combined rate of all four springs), the original
tension was on the order of 900 lbs. I DID notice some slight markings on
the "block" faces and the side gears, but these polished out with some fine
"wet-or-dry" paper and oil on a flat surface.

Bob Legere