Flexplate bolts - sealant or loctight ? Topic is solved

[Sveedy]

I getting conflicting info on this - Should I use a sealant or loctight on the flexplate bolts connecting plate to crank shaft hub ? Yes I'm reusing my old ones.
I can't see how there could ever be oil near the bolt threads in the crank shaft hub, but from what I've read there is ??

[Sveedy]

Well as I like to say, " when in doubt, split the difference ". So I think I will put loctight on the ends of the bolts, and thread sealer on maybe the last third toward the base. Then torque to spec.

[abscate]

I see a procedure to pull it into place with three screws 9995676 which are then replaced with 10 new screws fromVolvo. This usually means they have Volvo lock sealer on them.

Torque 45 Nm evenly, then 65degree angle tighten

[Sveedy]

So crack an egg of knowledge on me, because I can't for the life of me see how engine oil could ever be in contact with the threads of the crank hub bolts. The oil is inside of the rear main seal, so unless the crankshaft is hollow, how does oil come into contact with those rotating bolts and become an issue ?
Unless those holes for the bolts go clear through into the crankcase. ??

[abscate]

Every oil seal sips a little bit, it’s not uncommon for engine oil to be missed it and deposited around rear engine seals. My guess is if you pull up that part number on scandalous, you will see the bolts have Volvo sealer in red on them them

[kallekula]

I reused my bolts without threadlock or sealant. That was 10 yeras ago.

[Sveedy]

In this picture you can see through a bolt hole, the seam / sealant between the upper and intermediate sections of the block.
So that area should not have any oil in it. And there's the hollow split positioning post between those bolts which would allow oil to freely pass through ( passed a wire through it to check depth ), so then why seal the bolts on either side of it ?
I'm leaning toward loctight, not sealer. I'm guessing that the factory stuff does both, but they were using it for its locking aspect in this case, not sealing.

[erikv11]

I've done this a couple times and used loctite on these bolts, basically because I have always used this thread as a guide viewtopic.php?f=1&t=28973. Those ones haven't fallen apart in about 10 years.

[foggydogg]

It could well be that the Volvo bolts have a version of locktite that activates when torqued. The stuff does have some sealing properties, but not the primary function.
Since the originals were torque-to-yield, I would be tempted to just use some reasonable torque on the old bolts.

[Sveedy]

All done - Loctite only.

Thanks for the input guys !