Transmission catch can placement

[Jim Kaekel]

Having literally grown-up in a tranny shop, pretty much any racing automatic may blow fluid out of the vent. No matter how good the internal oil seals and sealing rings are, there is still a certain amount of pressure that leaks by and can blow out the vent. Just like an engine that has a small amount of blow-by that requires a crankcase breather system. Naturally, if the trans gets hot and fluid foams up, raising the fluid level, it will worsen the problem. Filling the fluid to the 1 pint low mark helps and won't hurt the trans. Sometimes just extending the vent by adding a hose run up to the firewall with a vent cap at the end will fix it. A trans-brake car probably is best with a catch can. I wonder how many transmission 1320 Racer has built? My .02.