Rear main bearing oil seals (again)

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ardiesse
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State: NSW
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Rear main bearing oil seals (again)

Post by ardiesse »

I've started a rebuild of an EJ motor, and in cleaning the cylinder block in preparation for reassembly, I found that the rear main bearing oil seal had been cemented into the groove, in both the block and the rear main bearing cap. The main bearings are stamped "HOLDEN" with no other markings, so they're original, standard size.

I'm thinking that the main bearings and rear seal have never been replaced. Which means that the rear main bearing oil seals were cemented in place at the factory. I'm no adhesives expert, but the cement is not completely hard-setting. It reminds me of mastic cement, or the adhesive that the factory used to glue interior trim in place, and headlinings to the window openings.

Questions, questions . . .

Was it GMH practise to cement the rear main oil seal in place?
Any guesses as to the type of adhesive used? (Something that doesn't set hard, is oil-resistant, and tolerant of high temperatures.)
Has anybody else come across cemented rear main bearing oil seals when stripping a motor down?

Rob
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Craig Allardyce
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Re: Rear main bearing oil seals (again)

Post by Craig Allardyce »

Rob, knowing how troublesome rear mains can be it's possible it may have been replaced midlife hence still he standard bearings.
I've been cementing mine in for sometime now (Permatex aviation gasket sealant) and I also centre punch the groove recess in four places in both the cap and block. I've never had an issue with the normal asbestos seals but these new graphite seals are terrible. My last seal in the EK spun in the block. It was like horse hair in the sump. The seals are too soft and compress a great deal.
Last edited by Craig Allardyce on Thu Jan 03, 2019 9:30 pm, edited 1 time in total.
ardiesse
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Joined: Thu Jan 19, 2017 9:57 am
State: NSW
Location: Sydney

Re: Rear main bearing oil seals (again)

Post by ardiesse »

Craig,

Thanks for the heads-up. I'm not the only one to have spun a rear seal in the groove on a fresh rebuild.
I was thinking of Liquid Nails, but the Permatex is probably a better bet. And I've seen centre-punch marks in the seal groove on another motor. So I figure - cement the seal in dry using a 6A6, trim the ends off, and then oil the seal well once the Permatex has set.

Rob
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Craig Allardyce
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Joined: Sun Aug 07, 2011 7:26 pm
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Re: Rear main bearing oil seals (again)

Post by Craig Allardyce »

I cemented mine in wet Rob. I never risk not soaking my seals for a few weeks before install. I am using NOS asbestos seals.
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