185 rear main seal question

Sat Oct 09, 2010 1:48 pm

I began replacing the rear main/ crankshaft seal today. I'm ready to install the new one, but I'm concerned that it isn't seating properly in the aluminum plate. It just falls in with a light push, and fits very loosely. I'm concerned that the old seal may have spun and enlarged the hole it seats in.

Is the seal supposed to fit so loosely, or do I need to try and find a replacement aluminum plate? Any ideas where I could find one if it's necessary?

Thanks

Re: 185 rear main seal question

Sat Oct 09, 2010 9:31 pm

The rear crankshaft seal will not be a
tight fit into its recess in the rear aluminum seal holder; plan on using some
Locktite 609 cement to hold it in place. (IH changed the
machining of the rear block plate, but 99% of the seals you buy will still be sized
for the older design.)

Put the Loctite 609 around the entire OUTSIDE of the metal part of the
seal where it contacts the back of the engine or else the outer seal surface will
surly leak.

Hope that this helps, NJDale

Re: 185 rear main seal question

Sat Oct 09, 2010 10:15 pm

Dale,

That's exactly what I needed to know, thanks a bunch. My new seal is a double lip type, I thought the open part of the lip faced in toward the aluminium block. Do I have that backwards?

Re: 185 rear main seal question

Sun Oct 10, 2010 12:30 pm

The 'open' part of the seal casing should face toward the interior of the motor. The 'solid' end of the seal should face outward, away from the engine and toward the flywheel.
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Re: 185 rear main seal question

Sun Oct 10, 2010 12:38 pm

There is a better fix for this problem. The seal changed and it no longer fits properly in the housings. A seal with a larger OD is available and housings are machined for the new seal with a proper 005-007 crush fit. Contact forum member Phil Lenke for a machined housing and new seal. As a bonus the housings are faced off too as many of them are not flat either. This is a far more reliable fix than adhesives which have had mixed results.

Re: 185 rear main seal question

Sun Oct 10, 2010 12:55 pm

here is a post with seal/retainer purchasing info: http://farmallcub.com/phpBB2/viewtopic.php?f=1&t=47084&p=389439&hilit=+seal#p389439