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Small block flywheel pressure plate alignment

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Rembrant

Small block flywheel pressure plate alignment

Hey guys,

I’ve been researching some stuff the past few days and I’ll explain why later, but do our trucks have dowel pins to align the pressure plate on the flywheel, or do they rely on the special shouldered bolts? I’ve been reading where in several cases guys have cured vibration issues when they found out that their pressure plate dowel pins were missing (apparently it is common for people to forget them after a flywheel resurface). Maybe this is a Mustang only thing since searching a lot of 302/5.0 stuff always ends up in Mustang forums.

Anyway, just curious what is supposed to be in there…

1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995

Rembrant

Re: Small block flywheel pressure plate alignment

Oh, and second…does anybody know what size the bolts are that mount an 11” clutch to the flywheel?

I see that ARP makes several bolt kits for the SBF, but it’s not clear to me which kit is the correct one.

I seem to recall the bolts being 5/16, but they may have been 3/8. It’s one or the other I assume, but there are kits with only bolts and others with bolts and dowel pins.

Rembrant

Re: Small block flywheel pressure plate alignment

Now that I go back and look at the pics on RockAuto, I see that there are no dowel pins…at least I don’t think so. Seems this was a Foxbody 5.0 thing…

But, it does mean that the correct shoulder bolts should be used.

I remember using different bolts but I can’t remember why. Would a 10” and 11” clutch require different size bolts on the same flywheel?

Gary Lewis

Re: Small block flywheel pressure plate alignment

Administrator

Apparently the clutch size matters. See below. Let me see if I can find the two different part numbers...

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Rembrant

Re: Small block flywheel pressure plate alignment

Thanks Gary!

Gary Lewis

Re: Small block flywheel pressure plate alignment

Administrator

In reply to this post by Gary Lewis

Yep, there are differences. From the 1986 Standard & Utility Parts Catalog (Documentation/Reference/Standard & Utility Parts Catalog): http://www.garysgaragemahal.com/standard--utility-parts-catalog.html

389571: 3/8-16 x 31/32 Grade 5

389572: 5/16-18 x 59/64 Grade 5

Gary, AKA "Gary fellow": Profile

Rembrant

Re: Small block flywheel pressure plate alignment

Thanks Gary,

I appreciate your help. I knew that I didn't reuse the original bolts, but I couldn't remember why. Obviously, they're different sizes, so thanks for that.

I'm still chasing a vibration issue (and the more I look into it, probably chasing my tail as well).

I have been reading about 302/5.0 vibration issues and I found what seems like a lot of people finding that the dowel pins were missing from their clutch pressure plate. Through a little more research, I found that that particular problem was just with the 5.0 Mustangs. Our trucks appear to use the 6x mounting bolts for alignment. That in itself is a problem, because I just used regular bolts in mine...although I'm not sure that it is a problem. I talked to a local transmission shop, and they said that regular bolts are a problem, and that they may be stretched or my pressure plate might be off center, or loose, etc.

Anyway, I might be pulling the transmission soon to check it.

Gary Lewis

Re: Small block flywheel pressure plate alignment

Administrator

Good luck! Hope you find it, soon.

Gary, AKA "Gary fellow": Profile