High mileage rear main seal replacement.

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Dec 5, 2018 | 08:37 AM

MikeManer

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Staging Lane

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From: Shreveport,LA.

High mileage rear main seal replacement.

I wanted to ask what you guys thought of the idea. I need to swap a high mileage engine into one of my trucks to hopefully get a couple more years of use out of it. The engine is 2003 and has 200,000 and doesn't leak now. I thought I would drop the pan to replace the oil pump pick-up tube O-ring, and I just wondered if I should leave well enough alone as far as the timing cover and rear main. I probably won't put over 15 or 20 thousand miles on the truck before I let it go. All opinions welcomed. Thanks
Mike

Dec 5, 2018 | 08:44 AM

arthursc2

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For $7, I'd just do it.

If you dont do it and it leaks in 2000mi, its a 6-10hr job to get it not leaking again.

Dec 5, 2018 | 03:15 PM

wretched73

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Just make sure you follow the instructions on how to line up the covers and pan correctly and you will be set.

Dec 5, 2018 | 06:05 PM

TXsilverado

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From: Humble Texas

I wouldn't touch it LOL.

Dec 6, 2018 | 12:44 AM

RedXray

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From: MAGA COUNTRY

IIRC GM redesigned the rear seal so the lip goes in the opposite direction over the crankshaft. Look carefully at the seal, in very tiny letters you'll see "This Side Out". It's easy to miss unless you're looking for it. This may sound odd but GM and Fel-Pro recommend the seals lip be installed dry over the dry crank flange.

Quote:

Note: Install the rear main seal dry; do not apply lubricant to the seal lips. It may seem natural to oil the seal, but in the case of the LS rear seal, its designed to install dry. If you lube the seal, you will probably create a leak. Carefully position the rear cover, with installer ring in place, onto the crank flange and gently push the cover into place. The trick is to keep the cover, seal and ring square to the crank flange. Once the seal slides over the crank flange, the white nylon installer ring will fall out. This may take a few tries, since the installer ring has a habit of popping off before the seal is started on the crank flange. Before fully seating the rear cover, inspect (using a small penlight) to make sure that the front seal lip is angled forward around the circumference of the crank flange. If the rear seal is installed with both seal lips angled rearward, you'll have a nasty rear seal oil leak.

Quote:

The seals themselves are designed to be installed dry - do not lubricate the inner rubber surfaces!