<VV> Diff Still Blowing Lube Out Vent

[Mikeamauro at aol.com]

I posted this issue sometime back; thought I had it under control, but it  
has reared its ugly head, once again.
 
Vehicle Specifics: 67 coupe 110, PG, 3:27 axle gear; the converter has  been 
modified for a slightly higher stall speed. The transmission is using no  
fluid (so I doubt it is passing fluid into the diff).
 
Symptoms: After an extended run at highway speeds (70-80 mph), upon  parking, 
and looking under vehicle the next day a puddle of diff lube can be  found 
under the vehicle. The puddle size varies, but most recently it  was about 
10-inches in diameter. Reaching up and feeling the top cover of the  diff, diff 
lube is found on top of the cover. As lube level lessens, amount  of blow out 
decreases. After a period of vehicle use, gauging level of diff  lube, by 
sticking digit into fill hole, becomes impossible: add more diff  lube and repeat 
cycle.
 
What I've Tried: Modified underside of diff cover, welding an additional  
baffle shield under OEM port leading to cover vent... no appreciable reduction  
in blow out. Replaced diff lube with synthetic lube treated (50%) with  Lucas 
Oil Stabilizer. Following this, blow out seemed much reduced, but still  
present: lowered lube level approximately 1" below lube fill port, and blow  out 
appeared to cease... until yesterday.
 
Can anyone comment on what may be causing this situation, and what possible  
fixes might be tried? For the racers: you stress the equipment well beyond the 
 limits of my everyday, highway use; do any of you take any special measures  
to keep the diff lube where it belongs? And, finally, how low a lube level  
(below fill port) can one operate, without damage to the diff?
 
Would appreciate any insights or ideas... thank you,
Mike Mauro 
 
 



**************************************Check out AOL's list of 2007's hottest 
products.
(http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001)