Lightened flywheel options

[RAC68]

Tahoe,
Who was talking about down shifting to first?

Roger,
From all I have read in this and other Forum discussions, I would say their is a high probability your flywheel has been lightened and see the quick reduction in RPMs between gear change as a major indication. Not knowing the extent of the RPM reduction but from the difficulty you are experiencing in up-shift gear selection, I would not be surprised that the extent of flywheel lightening is much more then the 7% offered by a Tom's Toys exchange.

Ray(64BJ8P1)​

 

[Bob_Spidell]

Ausmhly, most of us do not us 1st gear unless at stop preparing to go up hill. So, why sweat down shifting to first? Lots of pulling power in 2nd gear. Down shift when the car is not moving if needed.

Agreed, but if you have the taller 3.54:1 (Lempert) rear-end installed you will find yourself using 1st gear more often (it actually becomes useful).

WRT to synchros, well, synchronizing gears in a shift, I think, works to a point. Like brakes, synchros don't necessarily always lock up the two gears; I've found in shifting several cars, including both my Healeys and my '08 and '19 Mustangs, that if I really 'wind it out' in a gear, esp. second before an upshift I will get a bit of a nibble in the higher gear (esp. third). I sometimes wonder if some of the 'friction modifier' as used in LSDs might help synchros engage better?

ps. I think you have a few hills in Tahoe?

 

[RAC68]

It shouldn't matter much about rpm drop if the synchro is good - the synchro is basically a metal-to-metal brake and is intended to cause the two gears to rotate at the same speed so they will engage without grinding, and if good should do that whatever the speed is.
​

Hi Dave,

You make a good point and, from what I understand, it is not uncommon for a rebuilt trans to have original parts that are hard or impossible to get new. When addressing operational issues, I have found the issue is often the result of a few contributing conditions, including ware, and not a single failing component.

If you contribute a dragging synchro and rapid rpm reduction during upshifting from 1st, gear alignment may be far from perfect with gear clash increasingly common. The improvement or elimination of either and shifting becomes dramatically improved … maybe not perfect but acceptable.

Just my thoughts,
Ray(64BJ8P1)