[TR] TR3A timing chain lower gear

Randall tr3driver at ca.rr.com
Sat Dec 5 08:20:57 MST 2009


> Yes parts manual shows 2 shims

Two different sizes (.004 & .006), but both are listed "as required".

> so I though maybe installing 
> an extra 1 
> or 2 might get the lower gear out of it's little wear channel without 
> miss-aligning the timing chain too much.

Seems to me that would be even worse, since now the front edge of the gear
is sitting higher than the rest.

> As I don't see a split link to break the chain I'm assuming 
> the cam gear 
> comes off to remove the crank gear? (manual's not clear).

That's right.

> Oddly enough the alignment marks don't look aligned, not sure 
> whether I 
> should leave well enough alone or move the crank a tooth worth.

I wouldn't trust any marks.  If you want to check/adjust the valve timing,
IMO you should go through the whole megilla of finding TDC on the crank and
TDC on the cam, so you can compare the two.  A whole tooth off would be
pretty noticeable (it's adjustable in 1/4 tooth increments), so if the
engine ran OK before, it's probably right.

> There may be some of that but there's a definite channel the 
> gear falls into when the play increases.

Well, then the best approach is probably to pull the crank and have it
repaired/replaced.  But if you don't mind the thought of having to deal with
it again in a few years, a new gear & key plus some Loctite should get you
by for awhile.  When I had the front hub problem, my intention was to only
run that engine for another year or two, while I found time, money &
inclination to build a fresh motor.  That was around 1992 or so, and that
'temporary' fix was still working fine when the car was wrecked in 2004.

The Loctite I used was RC609 (still have the bottle, as I had to buy 50ml of
it), but 660 might be a better choice.
http://tinyurl.com/y9fpsum

Randall


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