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 Posted: Apr 29, 2019 03:11AM
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US
Agreed.  I suspect the oil leak my car had was from my improper installation of this seal 10+ years ago.

Doug L.
 Posted: Apr 27, 2019 10:11PM
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GB
Quote:
Originally Posted by Minimike1
even if you trimmed it, the oil would only run into the timing chain cover, not leak on the ground.

Bollocks would it.

The half moon seal will leak onto the ground quite happily as it seals the front main cap to the gearbox.  Yes it's kinda held in place by the back of the front plate, but that's a solid sheet of steel...
They used to leak so badly that BMC/BL/Rover developed a semi-rigid quick-change replacement.

I leave them untrimmed as a little compression seems to work nicely.  Coat of RTV on both sides and stick them in the recess between the bearing cap and the front plate rather than balancing on the gearbox and hoping.  Not had a leaky engine in years.

 Posted: Apr 27, 2019 05:05PM
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US
even if you trimmed it, the oil would only run into the timing chain cover, not leak on the ground.

 Posted: Apr 27, 2019 01:48PM
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US
Today I bolted the gearbox back onto the block.  All the threads I found on this subject agreed with Steve and Spank that the seal should not be trimmed.  Oddly, this is one location where almost everyone (in other threads) completed the installation with RTV applied to the seal.

I applied a little RTV to both sides and ends of the un-cut seal, placed it on the block next to the front plate, and lowered the gearbox in place.  With a flashlight you could see that the un-cut seal compressed neatly and cleanly into the space without bunching or popping out.

Thanks to both of you.  I am glad I did not trim the seal to length.  Hopefully this will be a leak free spot for a long time.

Doug L.
 Posted: Apr 24, 2019 05:27AM
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That's two who say "use as is".  I will take your advice but geeze that thing looks like it is at least 1/2" too long.

Doug L.
 Posted: Apr 24, 2019 04:21AM
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US
Having done a 1930 A Model Ford and a 948 Sprite before my first mini engine I did trim the seal in question. That would have been 1968/69 and I was a little upset to pull my first mini build for massive oil leak. Steve (CTR)

 Posted: Apr 23, 2019 08:27PM
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Use as supplied. They compress to fill the space once the weight of the engine is on the gearbox.

My preference is to glue them in place on the block/front mail with some rtv and stuff them up in there behind the timing plate with a screwdriver and then I sent the motor down on the gearbox, or if the motor is upside down on the stand, I sent the gearbox down on the motor.

 Posted: Apr 23, 2019 06:56PM
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US
Per the subject line....

The half moon seals provided with gasket sets are a bit long.  Are we really supposed to use them as supplied or are we supposed to trim a bit off? 
 

Doug L.