I wrench my own stuff, but I am pretty trans-stupid.
Of 6 AX-5 gears, 3 of mine became locked out. 1st and 3rd and Reverse. I was suspicious that 3 synchros were dying at the same time. Didn't seem right.
But three synchros dying is what THREE 'professional' 'mechanics' told me when they drove my Jeep. They all said I needed a new AX-5. $1500 bucks.
Found an AX5 with 15K on it on Craigslist. Seller was a Jeep Freak, and a licensed motorcycle mechanic whose own shop is being hit economically and handles big projects for cash at his house. This guy was military and straight up.
When we tore off the tranny what was left of the trans mount fell to the ground. The trans-clutch-engine were not lined up and for months my performance suffered.
He said he'd install a new mount and I'd be OK and did I still want the tranny! I said hell yes. Even though mine had 89K on it, I bought the 15K.
I'm happier, the Jeep drives like butter, I gained torque, and it cost me 400 bucks.
The moral of this story: If you think 3 professionals are still wrong, get a 4th opinion. Worked for me.