To the best of my knowledge, all the 235's had "bypass" filters, where a small quantity of oil is bled off through a restrictor, and is filtered and returned to the oil pan. Be sure the restrictor is in place, so the filter doesn't drop the oil pressure, and volume, to the bearings.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!