Refusing 3rd Gear

I have a 2004 Mazda 3i (less than 50,000mi on it) that is VERY temper-mental with 3rd gear. It’s a manual transmission, and when I up shift into 3rd & let go of the gear shift, the car, quite forcefully, rejects the shift. If I really want to I can force the shifter into 3rd, only to have it pop back out shortly thereafter. I have noticed that if down shifting into 3rd, however, the car doesn’t seem to complain too much. I’ve taken the car to a mechanic who told me it could be a bracket of some sort or that the entire transmission needs to be replaced. This leaves me looking at anywhere from a $200-$4000 bill, supposedly. I would hate to have to replace the transmission if I don’t have to. Any ideas?

It’s sounds like the transmission just needs repaired. I find it very hard to believe that a manual transmission would cost 4K to repair or replace. Get several quotes before you take the plunge. Skip the mechanic who told you it was a bracket or replacement. It sounds like a very wishy-washy diagnosis to me.

The problem could be with the shifter if you’re lucky. Then the shifting fingers will be seen and they might have a problem. After that, if nothing is found, it’s internal. Then the transmission has to come out.

I had the same problem on 06 mazda 3s. Exactly the same symptom with 3rd gear popping out when up-shifting. I only had about 23k miles at the time. I took it to the dealer and they replaced a “defective” synchro under warranty. At least that’s what I was told. They opted for taking the gearbox apart and replacing parts rather than installing a new one. Unfortunately, it took several other trips to the dealer after that to fix other things they did wrong with the gearbox but that’s another story…

If you are out of warranty, find a reliable transmission shop and get a diagnosis, but it may be hard to do so without the gearbox coming off (expensive)…

…Or you can just skip 3rd gear on the up-shift.

Sounds like an internal transmission fault in the synchronizer hub and sleeve and/or the 3/4 shift fork.
Is your car subject to a lot of city driving and do you have a tendency to drive around with your hand resting on the gearshift lever? If so, that’s the likely cause of the problem.

I do drive mostly in the city, I try not to rest my hand on the gearshift, but it does happen. I’m been just skipping 3rd gear, that seems to be the cheapest and easiest to deal with right now, however I am taking it into a transmission specialist here in town next week. We’ll see… Thanks for all the suggestions!