sealant choice for gearbox & timing cover

kwb210 · Apr 23, 2010

sealant choice for gearbox & timing cover?
I'm pulling the gearbox covers to make a quick inspection, purchased this 1975 Commando that has sat for 10 plus years undergoing a renovation. Thought it would be prudent to have a look see inside before starting her up and THEN finding out a problem. So I have new gaskets and want to know the top choices for sealant. I've read the Wellseal comments and see it for sale at http://www.pegasusautoracing.com/produc ... oduct=3304 for $21.99, ouch! Equal or near equal alternatives?
Kurt

PhiloMcGiffin · Apr 23, 2010

Permatex High Heat RTV (Ultra Grey)... apply to both sides of the gasket,,, make sure all surfaces are clean.

comnoz · Apr 23, 2010

If I use anything on a paper gasket its a little grease. If the surfaces are good they don't need sealant. A little grease makes them reusable. Jim

kwb210 · Apr 23, 2010

comnoz said:
If I use anything on a paper gasket its a little grease. If the surfaces are good they don't need sealant. A little grease makes them reusable. Jim

I started adding oil to the case, it had been dry for years, and a new paper gasket, drip drip drip. Soon all the oil was on the floor, so that was my main reason for puling the cases the second is as long as I'm in there to make an inspection for wear.
Anyone else have drips, big ones, on a dry gasket?

builder · Apr 23, 2010

kwb210 said:
Equal or near equal alternatives?

Nothing if your surfaces are really nice...the little grease trick does work!

If you use RTV sealant (Hi-Temp Silicone), you don't have to seal around the entire perimeter, only to the high point where oil will be present. Also, the RTV should be spread thin enough that if you were putting it on to newspaper, you could read the text through the sealant.

RTV is not a gap filler.

mike996 · Apr 23, 2010

Permatex Ultimate Gray motoseal - NO silicone! http://www.autoparts2020.com/rsdev/part ... R_ID=77603

comnoz · Apr 23, 2010

You must have a pretty crooked gasket surface or more likely a leaky kickstart o-ring. Jim

L.A.B. · Apr 23, 2010

comnoz said:
more likely a leaky kickstart o-ring. Jim

I believe kwb210's "1975 Commando" is a MkIII model, so it should at least have a proper kickstart oil seal, but of course it could still be the source of the leakage, I agree that the timing and gearbox cover gaskets should only need some grease on them.

daveparry · Apr 23, 2010

As others have said, no need for sealant with paper gaskets if surfaces are in good condition. I used Yamabond for metal to metal joints recently with very good results, (it wasn't a Norton though!)

daveparry · Apr 23, 2010

I meant to add, if surfaces are a little suspect, maybe Yamabond without a gasket might be worth a try.

swooshdave · Apr 23, 2010

daveparry said:
I meant to add, if surfaces are a little suspect, maybe Yamabond without a gasket might be worth a try.

As mentioned in another thread, Yamabond or equivalent like Threebond 1104. Any bike shop will be able to help you.

kwb210 · Apr 23, 2010

comnoz said:
You must have a pretty crooked gasket surface or more likely a leaky kickstart o-ring. Jim

Sounds like the first thing I need to do is check the surface for flatness. Foolish to goop it up (within reason(!)) and not have a proper surface. The kickstart area is dry, just a drip at the mating surfaces of the cases. Thanks for the great comments!
Kurt

pete.v · Apr 23, 2010

I use nothing on the gearbox cover and Permatex copper spray on the timing cover. It's nice to spray on a couple coat on each side of the gasket, stick on the gasket on the gearbox over the dowels and then it makes it easier to play with the clutch cable with the gasket already in place out of the way. Many times I have place the gasket on the cover, only having to remove it to attach the cable. Never again.

tpeever · Apr 23, 2010

Wellseal

maylar · Apr 24, 2010

For the gearbox and timing cover paper gaskets I use Permatex high-tack in a spray can.

sealant choice for gearbox & timing cover

kwb210

PhiloMcGiffin

comnoz

kwb210

builder

mike996

comnoz

L.A.B.

Moderator

daveparry

daveparry

swooshdave

kwb210

pete.v

tpeever

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maylar

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