Main bearing information
Posted: Fri Mar 09, 2018 2:20 pm
'Good Morning Ranger owners..
I get asked about main bearings quite often.. The two service letters
explain the reasoning for the change and some problems that developed.
I line bore the main bearing in each engine as this will correct the
problems mentioned in the service letter.. When starting the setup to
line bore, the studs are cleaned, pilot holes they go in are wire
brushed and lubricated..
Semi finished bearings are installed, case is assembled and main bearing
studs are torqued.. After bearings are bored, then finished in lathe
and milling machine, they are placed back in case and crankshaft installed..
Because of the distortion in the case, crankshaft will not turn until
main bearing studs are re-torqued.. After re-torque, it will turn
freely using one hand..
The distortion is why having bearings re-poured and machined to
crankshaft size does not work out very well..
Have a great day... John
[Non-text portions of this message have been removed]'
I get asked about main bearings quite often.. The two service letters
explain the reasoning for the change and some problems that developed.
I line bore the main bearing in each engine as this will correct the
problems mentioned in the service letter.. When starting the setup to
line bore, the studs are cleaned, pilot holes they go in are wire
brushed and lubricated..
Semi finished bearings are installed, case is assembled and main bearing
studs are torqued.. After bearings are bored, then finished in lathe
and milling machine, they are placed back in case and crankshaft installed..
Because of the distortion in the case, crankshaft will not turn until
main bearing studs are re-torqued.. After re-torque, it will turn
freely using one hand..
The distortion is why having bearings re-poured and machined to
crankshaft size does not work out very well..
Have a great day... John
[Non-text portions of this message have been removed]'