<VV> Different(ial) Opinions

[N. Joseph Potts]

If your tooth counts are accurate, you've got a 3.27, which were not put
into Corsas. You've got a transplant, there. Some people like the 3.27
there; I only have experience of the 3.55, which suits my conditions and
taste just fine.
     In several interventions into my differential (including replacing
shattered spiders), the ONLY part of my diff that has survived is the ring
and pinion gearset (these two MUST be treated as a matched pair - DON'T mix
and match). They DO get polished up in normal use, but the polishing is
neither a problem in itself nor a sign of anything untoward. I suspect your
ring and pinion are just fine.
     When I went to remove the bearing that is behind the nosepiece from the
pinion shaft, I found that the bearing had spun on the pinion shaft. If the
bearing comes off "too" easily, check for this condition and report it back
to the list if you find it. Take care to capture the shims under this
bearing and reuse them in reassembly. Also regarding your pinion shaft (the
repro replacements are, I believe, considerably superior to the originals
metallurgically), check the spline in its bore. The "lands" should be
roughly as wide as the grooves between them. If you find wide grooves and
narrow lands in there, you're looking at an incipient, absolute requirement
to replace that part. These grooves, of course, accept the output shaft of
the transmission.

Joe Potts
Miami, Florida USA
1966 Corsa coupe 140hp 4-speed with A/C

-----Original Message-----
From: virtualvairs-admin@corvair.org
[mailto:virtualvairs-admin@corvair.org]On Behalf Of Tom Wright
Sent: Monday, December 13, 2004 11:03 PM
To: virtualvairs@corvair.org
Subject: <VV> Different(ial) Opinions

Hi All.

I have now entered the tranny / differential realm of the 66 Corsa rebuild.
Actually, the tranny looks pretty good. The teeth are not chipped and even
the
syncro's look really nice. I am taking it for a professional opinion this
week
though, as I am this far into it I will replace whatever is marginal.

The differential is another story. It has (what seems to me) a fair amount
of
wear on the ring and pinion. Good pattern, no sharp edges, but coast and
drive
are polished up quite a bit. I am disassembling it anyway, I want to replace
the nose piece, check the bearings, replace the spider gears. I figure it to
be a 3.27 ratio (P=11, R=36), witch I thought low for a Corsa. I am planning
on 14" wheels, mostly city driving. If I have to replace the gears, what are
the opinions on rear end ratio's for this type of application? Any other
thoughts while I am this deep?

Thanks.

Tom Wright
St.Catharines
www.vaxxine.com/tomspage
66 Corsa 140