Bill,

Just out of curiosity, does the Sunfire have the F23 trans?

If so, how has it held up?

 

Yes, it's an F23. I'm pleased to report that we have yet to fail one in several seasons and hundreds of 10, 11 and 12 second passes.

The Getrag F23, and its stronger brother, F35 (as used in HHR SS), are among the most robust units in this segment. They feature a unique three-shaft design, whereas others have two shafts. This affords 50% more gear width potential, as well as increased rigidity via shaft strength and bearing area. Addtionally, their ring gear is rather sizeable, at over 8".

 

that's good news about the trannies,but why are some people having busted trannies???

 

I don't mean to throw stones at anyone who's had a trans problem, but it's been my experience that axle tramp (also called 'wheel hop') and excessive wheelspin leading to sudden hookup causes 95+% of failures. One-wheel burnouts are another no-no. Overly-agressive shifting is also a prime cause. I elaborate on some of these points in this webpage:

How Not To Break Your Driveline

 

Great car, good job. Good luck to your son, from a grizzled old 'Nam vet....

I offer a prayer for his safekeeping.