Pete, It sounds there are quite a few variables that could be adding to your issue. First and foremost, you mentioned the addition of your degasser and rerating your pumps for 1800 to 3600 RPM. Can you work backwards and bypass the degasser for a time (probably not with environmental regs) and/or pinch back on the discharge of your pumps? Maybe your pits are running dry? Can you increase your bushing clearance a bit more? As far as the steam jacketing, do you think 35# might be a bit low? Just throwing some things out there.