i am a proud owner of 1956 and 1957 roadmasters. i have changed several dynaflow rear oil seals over the years but they never lasted long. i tried different brands and parts shops but i just can't stop transmission oil dripping from the torque tube at the rear axle. is there a special trick or trap when changing the seal ? i now got the advice to shorten the spring of the oil seal, but others say it will lead to very fast wearout of the rubber. do you have the same problem ? did anything work for you ?
