<VV> Powerglide questions

[Karl Haakonsen]

Hi gang,

As I prepare to have my engine components cleaned, my thoughts turn to 
my transmission. So, I don't really know the last time the transmission 
was driven on the open road. Per the previous owner, the car was last on 
the road in 1972. That information may be suspect. However, what I do 
know is that I have never driven the car on the road in the 21-plus 
years I've had it. I did drive it around my driveway a bit in 1990, but 
the transmission never shifted up into high gear (top speed was around 
5mph). It worked like a champ between Drive (low gear only) and Reverse, 
though that was more than 21 years ago.

The question is, would most of you take the transmission apart to 
rebuild it just because it's out of the car and you're doing a full 
restoration, or am I inviting more trouble by taking apart a 
transmission that may be fine, given the reputation that Corvair 
Powerglides have of being bulletproof? Is there any way to assess its 
condition without taking it fully apart? Can it be flushed clean without 
taking it apart? Can it be removed without dropping the whole powertrain 
if I find that it doesn't work properly? Or should I just bite the 
bullet and rebuild it since it's out of the car?

Also, I will be replacing my torque converter. Clark's 2012 supplement 
extolls the virtue of the "high stall" torque converter for all 
Corvairs. I have some questions about that as well. I understand the 
concept of the higher stall RPM of the TC at the low end, but does this 
mean that there is more likelihood of slippage at higher RPMs or is the 
TC's response at higher speeds independent of its increased "slushiness" 
at the low end? I am less concerned about screaming performance than I 
am about gas mileage, and I don't have air conditioning on my car, so 
the benefits of a high stall TC seem more abstract to me, and I would be 
afraid that those benefits would come at the expense of more slippage at 
highway speeds, resulting in higher engine RPMs at highway speeds and 
thus worse gas mileage. I am clearly not an expert on the design and 
function of torque converters. Anyone here an expert on torque 
converters that can enlighten me about this?

Thanks!

Karl in Boston
www.chezhawk.com/VairBlog