Flywheel Bolts - renew ?

jeme9

Member
Messages
29
Reaction score
1
Location
Australia
Is it necessary to replace flywheel bolts ?
From BMW they are very expensive considering there are 8.
 

JFENG

Well-Known Member
Site Donor
Messages
3,177
Reaction score
1,393
Location
Bahston (Boston)
Does ARP make bolts for our M30's?
I've found their hardware to be of decent quality.
I used them on a recent engine project and they were cheaper than dealer prices.
 

rsporsche

Moderator
Site Donor $$
Messages
10,634
Reaction score
3,671
Location
Atlanta, GA
i have always heard the recommendation to replace them. i am planning to replace them when the euro b34 goes in. they aren't that expensive
11221717840 part number - $3.31 each from getbmwparts.com ... thats 26.50 for the set.
 

rsporsche

Moderator
Site Donor $$
Messages
10,634
Reaction score
3,671
Location
Atlanta, GA
not to mention the damage that will happen if one or more of these bolts were to back out ... hate to think what a flywheel out of balance would feel like
 

jeme9

Member
Messages
29
Reaction score
1
Location
Australia
Thanks guys, unfortunately getbmwparts.com don't ship to Australia, and Wallothnesch unfortunately have a min 75 euro shipping (which makes the AUD$9.50 ea from BMW cheaper). I will keep looking for some , thanks
 

Ohmess

I wanna DRIVE!
Site Donor $
Messages
4,833
Reaction score
2,639
Location
Aiken, SC
The reference book I used when I swapped my auto for a five speed recommended new flywheel bolts, so that is the way I went. I believe I ordered them through Carl Nelson.
 

sfdon

Well-Known Member
Site Donor
Site Donor $$
Messages
8,148
Reaction score
4,469
Location
sfbay area
8D505672-85E8-4BCA-B51D-05E0230F31DF.png
Either way-Loctite 270... that’s the red stuff
Notice the factory manual discribes them as “expansion” bolts.
Says replace, install with loctite 270.
 

lloyd

Well-Known Member
Messages
444
Reaction score
93
Either way-Loctite 270... that’s the red stuff
Notice the factory manual discribes them as “expansion” bolts.
Says replace, install with loctite 270.

The description of "expansion bolts" suggests these are what have been commonly referred to as single-use torque-to-yield bolts. In that regard, I distinctly recall a machinist comparing used and new flywheel bolts with a micrometer and concluding that since they appeared dimensionally identical, he reused the old ones on his own M30 engine. While I am not advocating a contrarian view regarding reuse of flywheel bolts, especially in light of the manual's admonition, I can think of a few examples of reuse (mostly on M10 engines) without any adverse consequences.
41g7zUg8gSL.jpg
 
Last edited:

sfdon

Well-Known Member
Site Donor
Site Donor $$
Messages
8,148
Reaction score
4,469
Location
sfbay area
I always use loctite and I have never bought a new bolt.
Never had a problem.
Always figured that factory goop was to keep oil from migrating...
 

jeme9

Member
Messages
29
Reaction score
1
Location
Australia
I also spoke to a mechanic business here (who specialises in e9's) and he said they usually re-use flywheel bolts on manuals.
That being said if I can get some at reasonable price in Australia I will replace them.
Note: my manual also says torque of 100-115 Nm

I am also replacing clutch pressure plate and friction plate, but have no plan to touch the flywheel surface.
 
Top