After taking apart the GSR trans and doing some research, I decided that it was cheaper to put in an LS 5th gear and synchro sleeve vs paying $150 for a new sleeve from Acura.
LS 5th Gear
It just so happened that I have had in my possession a CABLE 5-speed LS transmission with a bad 3rd gear synchro. Considering that no one really beats up on 5th gear, I decided to rip out the good stuff in the cable LS.
Here's a shot of both trans on the workbench coffee table: (GSR on right, LS cable on left)
Gear ratios on GSR vs. Hydro LS vs. Cable LS transmissions are as follows:
GSR 5th: 0.787
LS (C) 5th: 0.742
LS (H) 5th: 0.714
I counted the teeth and verified both transmissions before proceeding.
As it turns out, the LS cable 5th is right smack dab in-between a standard hydro LS and a GSR transmission. Hopefully, this will be the perfect median between highway crusing and still having SOME ability to accelerate in 5th.
The engine this all is being bolted on to is a USDM B20Z.
To get the mainshaft/countershaft out of the tranny, you simply lift straight up. They come out together.
I then took the secondary shaft to a friends house and had him impact off the top nut.
To get the gears off the secondary shaft, you simply flip the shaft, and drop it on a block of wood like so:
Here's a shot of the secondary shafts next to each other with the gears pulled off: