vmathy

Quick Question I am putting a stock clutch fan on my 72 455. What is the correct length for the bolts?
Thanks in advance

Yellowstatue

Usually there are studs screwed into the W/P, fine thread on one end and coarse threaded on the opposite end. I think they are called machine studs? A nut and lock washer holds the clutch onto the studs... they are about an inch long and if you use ones that are too long then they will jamb the hub if you screw them in too far.

MDchanic

Just go into the auto parts store and ask for water pump studs - they come on a Dorman "Help!" card.

- Eric

71CutlassS455

reviving an old one here but trying not to be wasteful...

why use the studs? would a bolt and lock washer not do the same? is it easier to install?

sorry i'm converting from a efan back to the stock setup and my water pump just has a pulley and four screws.

oldcutlass

It just makes it easier, bolts would work also.

MDchanic

Studs allow you to set the fan in place and then screw on the nuts.

Screws would require you to juggle the fan, with all the screws in place, into position, and then hold it in place while you started all the screws. Try it sometime and you'll understand.

- Eric

71CutlassS455

you are all so right, looks easy enough to bolt it on but man, unnecessarily difficult. I just went to pep boys to get the studs and slapped it n in a few minutes.

Question, Since i can't feel or see the threads behind then pulley - how far should the studs screw in? I just put them in with enough thread showing to get the lock washer and bolt on. not tight by any-means, just kind of sitting there waiting for the nut/washer.

MDchanic

Yeah, that's okay. You can grab the unthreaded bit with a pair of small Vise-Grips and give it a twist if you want.

- Eric

oldcutlass

Put double nuts on them, tighten the nuts together and then tighten the stud, remove nuts and repeat 4 times. Then install the pulley, clutch, and/or fan. Very simple.