Re: Stag Alternator Replacement

[Tim Buja <buja@domain.elided>]

Bruce Koehler wrote:
> Any suggestions on an alternate Alternator for my (72) Stag? and how
> to?   The Lucas in it wore a brush down to the spring and tore up the
> slip ring (commutator).

Glenn Merrell replied:
: I'd check with your local electrical starter/motor/alternator repair
: shoppe. You may be surprised that they will rebuild it for less than
: $100.  There are several shops here in Colorado that do alternator
: rebuilds and a fine job on Lucas 18 ACR series ones.
:
: Moss caries the Lucas 18ACR alternator along with Victoria British
: and The Roadster Factory.  Also try Wayne Bier at Triumphs Only in
: San Jose.

I just had my 18ACR alternator rebuilt locally for $85, and it was ready
by noon the next day(!).  The problem with my alternator was that the
drive end bearing had elongated the hole in the front half of the case,
causing the rotor to rub on the stator.  The local shop replaced both
bearings and the worn case half, reinsulated all the windings, and
replaced the diode pack.  The alternator looked like a brand new part
when I got it back.  Parts are still available for your Lucas alternator,
so I wouldn't be in a big hurry to replace it.

It may be possible to replace it with a higher capacity alternator,
but these tend to be larger in diameter and may not fit in the tight
quarters of the Stag engine compartment.  There isn't much room
under the exhaust manifold, and fitting a larger unit may force you
to permanently remove the air conditioning compressor to give you
enough room to move the alternator there.  One advantage to that
location is that you would no longer have to remove the anti-sway bar,
lower fan shroud and automatic transmission cooler to remove and
reinstall the alternator.

For information on replacing a Lucas alternator with a higher rated
General Motors alternator, point your browser to:
http://www.vtr.org/maintain/alternator/gm-tr6.html
While this article is specific to the TR6, the wire colors and general
theory should carry through to the Stag.

If you decide to get a replacement Lucas alternator from Moss, TRF,
Victoria British, etc, make sure that you remove the alternator
fan and pulley before you send in your old unit as a core.  The
fan and pulley seem to be specific to the Stag, and the alternator
you get will probably not have a fan or pulley installed.  The
alternator on my Stag is a battery voltage sensing (four wire)
unit - you may not get one of these back if you exchange yours for a
rebuild instead of getting your own unit rebuilt.  Another thing to
be aware of is that the mounting "ears" may differ in location
depending on which side of the engine the alternator is mounted.
If possible, it's always better to get your own alternator rebuilt
rather than exchanging yours for a rebuilt unit.  

Tim Buja - Rockford, Illinois, USA - 80 TR8, 73 Stag, 72 TR6