1998 Honda CRV • 100,000 miles

My 1998 automatic transmission Honda CRV (RD1) wont shift gears at high values of RPM and this problem started abruptly, when I switch off the engine and restart it starts shifting but I will not go far with it or else am towed back. I changed the transmission fluid but got no positive result. The latest diagnosis gave the verdict: TCC Solenoid Valve (Failure P1753). My mechanic thinks I should buy another gearbox which is very expensive. Is it possible that the gearbox can be repaired or do I just start looking for a complete unit. Duncan, Nairobi, Kenya.
February 16, 2012.

The torque converter clutch solenoid is replaceable. Is there a reason he doesn't want to replace the solenoid?

Thanks Jacobandnickolas for the reply, I think the major problem is availability of the part, can you assist with acquisition of the same, I would really appreciate.

Feb 17, 2012.