OMC 5.7 / 350 - Flywheel washers (what to use?)

[rybad]

I replaced the engine block (1988 GM 350/5.7 - OMC Cobra)<br /><br />I am putting the flywheel, and engine coupler back together, but I can seem to find a grade 8 washer that is the exact size to fit on the stud coming out of the crankshaft flange.<br /><br />Does anyone know where to find these type of parts? I have tried several local hardware store, a performance engine shop, several boat service shops, and ACME Nut & Bolt!! I find it rediculous that I can find these!

 

[Buttanic]

Re: OMC 5.7 / 350 - Flywheel washers (what to use?)

I don't believe washers are graded like bolts. I belive the studs are 7/16 you should be able to find 7/16 cylinder head bolt washers at an automotive machine shop. They are hardened and thicker than a regular washer. Frankly I believe any flat washer would be fine, just be sure everything is properly torqued.<br /><br />Buttanic

 

[Buttanic]

Re: OMC 5.7 / 350 - Flywheel washers (what to use?)

I don't believe washers are graded like bolts. I belive the studs are 7/16 you should be able to find 7/16 cylinder head bolt washers at an automotive machine shop. They are hardened and thicker than a regular washer. Frankly I believe any flat washer would be fine, just be sure everything is properly torqued.<br /><br />Buttanic

 

[rybad]

Re: OMC 5.7 / 350 - Flywheel washers (what to use?)

I have been able to find Grade 8 Flat washers, and the old one's "look" like typical grade 8 (with the gold tone).. but the old washers actually "seated" into the holes on the coupler (making them no longer flat) - I would have thought that grade 8 would be hardened enough not to disform in that way - so possibly, they are not hardened. This is why I am struggleing to find the correct washer .. I'm not a machinic, and don't know if it really makes a difference. The problem is that the grade 8 washers I found thus far, have a larger centre diameter that the original ones, and Im leary about using them, since there would be some "play" around the stud.

 

[Buttanic]

Re: OMC 5.7 / 350 - Flywheel washers (what to use?)

I think the head bolt washers are what you are looking for.<br /><br />Buttanic

 

[rybad]

Re: OMC 5.7 / 350 - Flywheel washers (what to use?)

Thanks.. Actually, I found a part number (304671). Talked to a reliable repair facility today, and they said that there has been an unusually high request for these specific washers, and there is a re-man. order in, but will be about 2 weeks to get.<br /><br />I also talked to a mechanic there, and he told me they usually just reuse them. They are made of a soft metal, so that they mushroom down into the hole on the coupler..<br /><br />Thanks for you suggestions.

 

[Peter J Fraser]

Re: OMC 5.7 / 350 - Flywheel washers (what to use?)

You could also try your local CATERPILLAR Equipment dealer. Have a look in their book called "One Safe Source". It lists all the diamensions for the hardware.<br />ALL CAT hardware is grade 8 or higher. Be careful though because if the seat area is not flat you will risk cracking the washers when the bolts are torqued up because the tensile strength is so high.<br /><br />Good luck<br /><br />Peter