I have an HF transmission that was totally overhauled (all new bearings, seals, and oil guide plates) in February 2006 that I am about to remove from my car. It still runs like a top, but it does not suit my driving needs anymore - I need shorter gearing for driving in the mountains!
My car had 245,600 miles on it when I installed the transmission, and I turned 300,000 yesterday, so that puts the mileage on the transmission at about 55,000 miles.
Not to toot my own horn, but I have overhauled many Honda manual transmissions over the years, and all are still running fine, to my knowledge. I'm just saying I know what I'm doing, and either have the tools, or have access to the tools to do the job right.
I did not install new synchros, as they were not needed - the box still shifts like butter.
Wait, Let me slow down. I have a 91 DX. Manual Transmission.
I have also had a VX VTEC-E engine (from Canada) put into it, running a P07
Would love to find a manifold with the Catalytic converter on it. Getting only 43 MPG now with the DX tranny with 319,000 on the Odometer.