[TR] TR-3 Rear Crankshaft Seal

Randall tr3driver at ca.rr.com
Mon Apr 9 15:24:53 MDT 2012


> ISTR that there are a couple of options for replacing this seal with
> modern
> technology. TRF's Viton seal doesn't require machining the crank, while
> Moss's
> does. Are there any other options?

According to an article published in the local club newsletter many years
ago, there are (at least) two versions of the "grind the crank" conversion.

Also, while it's not exactly modern technology; supposedly the original seal
works quite well if you use a mandrel with the proper dimensions.  The
dimensions given in the manual are not correct.  I believe TRF sells
mandrels with the updated dimensions (last I heard, Moss did not).

Personally, I am going with the Viton seal.  This conversion was developed
by a well-known Triumph racer, running on race tracks where "marking its
spot" can get you disqualified (and barred).  He tried the other conversion
and found it wanting.

If you do go with one of the "grind the crank" conversions, be sure you get
the right dimensions for grinding the crank.  The instructions have been
revised multiple times, each time making the crank surface larger.  Also
check out "uncle jacks" web site for installation tips.

-- Randall 


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