Water pump opinions

[fairdeal]

Just noticed that newer water pump on F engines don't have plastic spacer and metal collar, don't have three washers above impeller, as older engines have. Rubber impeller already jammed very tight inside water pump stainless steel cup and plate may be later those parts were considered useless? may be older engines may work without those parts?.

the larger HPs - 250 and above? don't - but still there on the smaller engines.

This site teaches that those parts have nothing to do with water pump operation -
serve -only if properly installed - to take up gear backlash/ eliminate low-rpm LU sounds
and are non-essential to operation

[robert graham]

My C90 doesn't have this collar and rings....always heard it was for gear lash for certain types of gears/lower units...

[TownsendsFJR1300]

My 06 F150 has them all...

[rodbolt17]

small inline engines use a gear set cut so it pulls the shaft down when loaded. V4 and larger the gear shoves the shaft up.
most f250 and up use a pretension spring assy to hold the shaft against the bearing.