[Paul Workman]

When I had my base 95 car, I too had that "rare reverse spline lubrication failure". Bill Boudreau reams the oil galleries out to a bit larger to (he said) assist w/ lubrication - as part of his "blue-printing" procedure on the ZF. But, he went on to say that if I opted not to have my replacement trans undergo his procedure, to be sure to use a synthetic oil.

The Castrol 10W-60 synthetic is no longer available (been re-formulated, as I understand it). But, as an alternative, Marc Haibeck recommended the Red Line High-Shock, synthetic gear oil as a substitute.

My transmission is in need of a Boudreau "laying of hands". However, the crunching I sometimes get when shifting into 5th (especially when cold) is noticeably less since the switch to the RL product.

This thread provides some new product info (to me). But, FWIW, I've driven 2 full seasons ≈ 7000 miles, and many WOT runs with the RL w/o problems.