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Ok, so I got the transmission out of the car (RECORD BREAKING 2 HOURS AND 50 MINUTES!!!), then removed clutch and pressure plate, expecting to find nicks and abrasions on the clutch and flywheel bolts. I did not see any! Please note this is in reference to the engine knocking that was thought to be caused by loose flywheel bolts. Now, the flywheel bolts were loose, even though I used medium strength loctite and torqued them down to 90 ft/lbs....I mean finger loose, they were loose, loose, loose, loose! But no marks on the bolt heads or clutch, so how exactly would this cause the knocking noise? Flywheel slapping up against something?
 

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Imagine that flywheel (and the Alfa flywheel is heavy) spinning around at 3000rpm with the bolts only finger tight! No wonder it made noise.

Now, why do we suppose it got loose? Was there something in the way that prevented it from being fully seated when you installed it? Are the threads damaged?
 

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Ok, so I got the transmission out of the car (RECORD BREAKING 2 HOURS AND 50 MINUTES!!!), then removed clutch and pressure plate, expecting to find nicks and abrasions on the clutch and flywheel bolts. I did not see any! Please note this is in reference to the engine knocking that was thought to be caused by loose flywheel bolts. Now, the flywheel bolts were loose, even though I used medium strength loctite and torqued them down to 90 ft/lbs....I mean finger loose, they were loose, loose, loose, loose! But no marks on the bolt heads or clutch, so how exactly would this cause the knocking noise? Flywheel slapping up against something?
Ugh! I've been through something like this. Inspect the end of the crank and the hole in the flywheel that fits on the crank, that is where I would expect you would see the wear from the flywheel bolts to the crank being loose. I had deformation of the hole in the flywheel that fits on the crank and wear on the end of the crank. I used emory paper on the end of the crank and changed the flywheel. Hopefully the loose flywheel, having upset the balance of the engine, has not damaged the the crank/bearing interfaces inside the engine. My reference book states the flywheel bolts are to be "oiled" then torqued, like the head bolts/nuts.
 

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Discussion Starter #4
Oh, yeah, the flywheel bolts will get "oiled" before reinstall. Oiled with gobs of loctite...actually, does provide a lubrication effect while wet, this time though, she's getting torqued down to 105 ft/lbs. No noticeable deformorities of the input shaft or crank. I'm still in awe of how an over revving engine caused this...
 

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Alfa TSB #89.06 dated June 1989 for all Bosch injected Spiders states to apply Loctite to the flywheel bolts (doesn't specify which type of Loctite) and torque the bolts to 81.1-83.3 lb/ft.
 

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If really desperate, one could get all finicky with crossdrilling the bolt heads and use safety wire laced through them too.

Then they really won't back out even if loose. (more than a 1/16th - 1/8th turn anyway)
 

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The only time I had my flywheel bolts loosen up with locktite is when I tested everything before letting the locktite dry. I wasn't even thinking and it must have all wicked out of the threads. The next day driving was fine until I did a rev up to redline then I started getting the clackety clack.

Kevin
 

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Total confusion is a great headline for this topic. I think of "gobs" of loctite similarly to gobs of silicon gaskets sealer, a little maybe OK, but too much isn't. The car I had came with the flywheel problem courtesy of the previous owner. I find it interesting the loose flywheel bolt stories all involve locktite. I've intstalled over the years at least ten 105/115 flywheels using the "oiled" method and never had any loosen-up, with the caveat all were Weber or SPICA motors
 

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I heard of something similar from a local alfa driving instructor.

He told me of a day when he over reved his engine, i think my dropping in too low a gear. It stretched the flywheel bolts and made it clanky. He couldn't figure it out as the engine seemed fine. Then he asked a more experienced racer who told him of his time over reving and stretching the bolts.

Point is if the engine over revs too quickly, like 4k to 10k in 0.5 seconds, those bolts will deform. Once they deform, they are useless, they may "look" ok but I would throw them away. It takes a lot of power and energy to make a rev like that happen, and it all goes thru those bolts.

So, you might want to get some new bolts.

p.s. I do not know how you over reved your engine.
 

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also, you really do not want loctite under the head of the bolt, when it wears away the bolt is not tight, or not as tight, as it was. I would only use a little red, and put it in the female thread instead of on the male, this prevents it from getting under the head.

You could also use green wicking type 290 after you have torqued the bolts and wiped the oil clean.
 

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Ever heard of replacing flywheel bolts and not reusing them?
The old locktight gets hungup in the threads and gives a false torque reading.
I use oil on the old bolts and run them in and out several times to break up the old thread lock. Then I flush the holes with an eye dropper filled with laquer thinner, or carb cleaner spray, Keeping the rear main seal from getting soaked.
I clean the bolts with the same cleaner. Blow everything dry with compressed air. THEN apply the thread lock and torque down using the similar method of bolt rotation that you would use on a cylinderhead.

OF course making sure that the flywheel is in the correct position.

So far, no loose flywheel.
 

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I agree with Stan Murray.
if there is any old gunk or oil left the locktight will not work right.
I run a tap in the holes and a die over the bolt. that seems to get all the old gunk out then clean as Stan said but I use acetone. I also use Q-tips (cotton swabs) to clean out the holes. if I run a Q-tips soaked in acetone and it come out with black stuff on it it is not clean and needs more work. it needs to be spotless. Any oil even finger prints can keep the locktight from working.
 

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Discussion Starter #16
Flywheel, clutch and pressure plate are all back together. Every bolt checked for correct torque THREE TIMES! No more mishaps from an over revving engine or not!
 

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