924Board.org

genikz88 · Joined: 29 Mar 2006 Posts: 64

Does anybody know of a source for new flywheel bolts, besides the stealership? They want $20 EACH. $120 for 6 bolts is hard to swallow.

This is for my brothers '78 924 2.0L

They are:

M12 x 1.5 x 22MM x grade 10.9
(shank size, thread pitch, length, strength)

Thanks!
Chris
_________________
Chris
'88 924S

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Since you know the diameter, pitch, length, and strength of the bolts, you should be able to go to any hardware store, or specialty bolt supplier, or bolt manufacturer, and buy bolts with the correct specifications that would work properly.

After all, Porsche does not manufacture bolts themselves from special unobtanium materials. They buy bolts the same way everybody else does, from the same suppliers and manufacturers.

Just make sure that you have the correct specifications for the bolts, including the head dimensions. If you get the get dimensions wrong, it is possible that the bolt heads could interfere without another component. For example, I don't know for sure about 924s, but I know that with 914s there is a problem with the flywheel bolt heads hitting the clutch disc when the flywheel has been ground too far during a clutch job. Replacement flywheel bolts could cause a problem like this. For this reason, I would not automatically figure on cutting the flywheel on 914 when replacing the clutch.

genikz88 · Joined: 29 Mar 2006 Posts: 64

Thanks for the response.

We looked everywhere (ARP, Ace, McFadden Dale, McMaster Carr, etc etc) and can't find any that are 10 - 9 grade steel.
_________________
Chris
'88 924S

Lizard · Posted: Fri Jan 12, 2007 6:44 am Post subject:

try a marine hardware supplier.
_________________
3 928s,

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

You probably just pushed the wrong button, but the strength is 10.9, and not 10-9, as opposed to a common bolt which would be rated 8.8.

Have you considered buying a longer bolt and cutting it down?

I am sure that my local hardware store sells the right bolts in what is probably a 25mm length.

In fact, I'll drive down there and check a little later.

To tell you the truth, unless the flywheel bolts or clutch pressure plate bolts are damaged or show signs of questionable servicing practices (distorted heads from air gun tightening or using the wrong wrench) when I remove them, I do not normally replace them when servicing the clutch and flywheel.

I have only seen one broken pressure plate bolt, and that one broke when I was changing the clutch in a 72 Mercury Capri about 30+ years ago. I as removing a bolt when it snapped. It wasn't rusted, and the remaining threaded section of the bolt that was in the flywheel unscrewed with finger pressure. Back then, I could replace the clutch in a Capri in 45 minutes from drive up to drive off. Seems I knew at least a dozen people (5 or 6 in my family alone) driving the cars back then and while our clutches lasted a long time, we were all driving a lot of miles (60K-80K) a year.

angeloz · Joined: 11 Jan 2007 Posts: 19 Location: New York State

gohim posted the following under throwout bearing failure in error I beleive:

My local hardware store carries M12-1.5 25mm bolts. But they're only grade 8.8, at $1.60 each.

I did a quick Web Search and found this company

Coburn-Myers Fastener Systems

email: sales@coburnmyers.com

Item # .12F25MHF/10.9, M12-1.5 X 25 HEX CAP SCREW DIN 961 CL 10.9

This is 25mm and full threaded. there is also a listing for 20mm, fully threaded. So you could go short, or you could cut them down. Measure the thickness of the flywheel, and add it to the thickness of the crankshaft flange to determine if you can go short or long.

Is this what you were looking for?

Minimum Order is $50, and they take credit cards.

Toll-Free Phone nUmber 800-662-7459
_________________
1980 Porsche 924 Special Edition
40K miles - showroom new - 2nd owner

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

Standard bolts come in 5 mm length increments, so you won't get 22 mm from a general supplier. Go for the 25s and grind the end down if necessary.

DO NOT be tempted to go for the 8.8 grade. You need the 10.9 grade for flywheel bolts.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

Paul · Posted: Sat Jan 13, 2007 1:42 am Post subject:

www.boltdepot.com
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Lizard · Posted: Sat Jan 13, 2007 3:12 am Post subject:

I wouldnt recommend just grinding it down, mark the length then use a zip disk or a hacksaw.
_________________
3 928s,

genikz88 · Joined: 29 Mar 2006 Posts: 64

Thank you for the responses everybody! I'll pass this info on to my brother.

Thankfully we haven't thrown much of his car back together, so we can still easily reach the flywheel.

I'll try to convince him to reuse them, but it sounds like there is a much cheaper alternative than $20 per bolt.
_________________
Chris
'88 924S

genikz88 · Joined: 29 Mar 2006 Posts: 64