Flywheel Bolts - Signs Of Thread Sealant? - Vintage Mustang Forums
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post #1 of 7 (permalink) Old 04-19-2019, 06:37 AM Thread Starter
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Flywheel Bolts - Signs Of Thread Sealant?

I tore everything down for my T5 conversion and when I pulled the flywheel bolts they were very wet with oil and clean, no sign of any sealant.
I am hoping this explains the small occasional drip i have been getting and all the oil slung all over the inside of the bell - and the chattering clutch. The engine was rebuilt by a shop before I bought the car and I am hoping they forgot to seal the flywheel bolts, it would save me from having to replace the rear seal.

So, if they did seal them, would thread sealant leave behind any signs that it was on the bolts?

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post #2 of 7 (permalink) Old 04-19-2019, 07:11 AM
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Any bolt that's had sealant on it will show it. However, you can't tell very well if it's been unscrewed later and run back in.

I've never seen a serious leak from these bolts though, sealed or unsealed. If they're torqued properly, it's pretty difficult for oil to get past 'em. If your engine's the old 2-piece seal, then you can almost bet that's your problem.
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post #3 of 7 (permalink) Old 04-19-2019, 07:23 AM Thread Starter
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There doesn't appear to be ANY sign of sealant on these bolts, I will take a closer look today at the rear seal.

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post #4 of 7 (permalink) Old 04-19-2019, 07:33 AM
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Sounds like they did not use sealant, if they had there would be no oil on the bolts. Use Loctite on your flywheel bolts to prevent them from backing out and to prevent oil from seeping out. Others can chime in if they think differently as some say to use sealant but IMO, Loctite. It could still be the two piece seal so check that area as well. Good luck, Jim
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post #5 of 7 (permalink) Old 04-19-2019, 09:08 AM
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I used this

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post #6 of 7 (permalink) Old 04-19-2019, 11:39 AM
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Iíve put them in the past without sealant. Youíll probably get a little weeping but I didnít notice that much. Iím using ARP bolts, they recommend the blue Loctite which is what I used. No good reason not to use it even on stock bolts.
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post #7 of 7 (permalink) Old 04-19-2019, 02:18 PM
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Factory Ford flywheel bolts are grade 8 , self locking and self sealing. There is no reason to use a sealant or thread locker. When torqued to 75 ft lbs they will not leak or loosen up. I can not say the same for aftermarket bolts. "IF" your bolts are weeping , you will see "tracks" because of the clutch dust clinging to the oil. Check the input seal or rear main seal too which is more often the cause.
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