...........and check for leaks. Then rotate the crank and do it again, repeatedly. Changing a rear main seal that may be fine may create more havoc, JMO, Rod.
Mickey Thompson's 63 1/2 #997 S/S Hi-Rise 427 Lgt/Wgt Galaxie,
1957 C-600 Cab-over carhauler w/390-4V, 2-speed rear-end
FGCofA member #4908
MCGC member #75
"There will ALWAYS be an FE in my LiFE"