We have a twin but each shaft log is between the center-mounted generator and the fuel tank "cube" mounted outboard of each shaft. So it's pretty tight quarters. I use a short pipe wrench to free the lock nut on the packing gland (I keep all the threads or both the lock and adjustment nuts heavily coated with waterpoof grease but it still takes a good pull to separate the two). Once the lock nut is "unstuck" from the adjustment nut I back it off more by hand and then use one of those rather crappy packing gland adjustment wrenches you can buy at places like West Marine to adjust the adjustment nut. It's too thin so can require using your other hand to keep it on the nut but it works okay. Once I've set the adjustment nut to where I think it should be I run the lock nut up against it by hand and then give the lock nut a tug with the short pipe wrench to seat it.