Toyota Repair: 3RD Gear, gear oil, syncro

Question
Hi, I have an 1986 Celica GTS 5 speed. 145,000 miles. It all started today.. When im accelerating quickly and changing from 2nd to 3rd it has a little grinding to it but it goes in gear and sounds fine and the rest are fine too.. Could it be a synchro? And about how much does that cost?  

Answer
If it only does it in 1 gear , sounds like a syncro. A weak pressure plate will do that, but on all shifts.

You can try changing to a lighter gear oil and add a limiteed shift additive,might free it up if its just stuck.

May be cheaper and more practicle to replace than repair the trans.
Try www.car-part.com

Mike