Manual Transmission hard to shift, won't go into 1st or 5th Gears

Question

Scion tC 2005, 146,000, mostly highway miles. Front wheel drive.

From standstill, having trouble shifting into first, only when engine is running. Once the engine is off there are no issues shifting into any gear.

If I manage to get it into first, by forcing it basically,second gear is also tricky. There is some resistance about halfway into shifting, but it'll go. Third and fourth are no problem. Fifth gear even harder to shift into than first.

This just started this evening. On the way home I just just tried to shift into first before coming to a complete stop at stop lights, as it is easier to get it in gear right then (vs struggling with it once the light changes).

After I pulled into a parking lot to try and investigate, it reverted back to normal, but just momentarily. As soon as I continued home it started doing it again.

I bought the car used at 92k. As far as I know, the clutch and transmission have never had any problems, and never have been serviced.

Can I get away with driving it to my mechanic (about an hour 1/2 away) with zero traffic, at highway speeds, minimal stops/ shifting?

I have no experience working on any part of the clutch assembly, yet. But willing to take a crack at it.

What could be it be? Clutch wear? Fluid issues?

Transmission?

Answer 1

I suspect the reasons for first and second gear are non-optimal alignment of transmission parts and worn synchronizers, respectively. About fifth, I don't know, it shouldn't suffer easily from synchro wear.

Usually you switch to first gear from neutral at standstill. Nothing is rotating, the synchronizers don't have to do anything. But the transmission parts are not rotating, so if they just happen to be non-optimally aligned, the shifting may be impossible. The solution is to either (1) switch to second gear, then try again shifting to first gear, or (2) put transmission to neutral, release the clutch for a split second, depress the clutch, and try to shift to first gear again.

However, it's also possible to shift to first gear from second. This is a massive downshift due to the big difference in gear ratios. The synchronizers have to do a lot of work to do this shift and it's supposed to be hard even in new vehicles with unworn parts. To make downshifting to first from second easier, you have to learn double declutching technique.

Shifting to second from first requires work to be done by the synchronizers of the second gear. They gradually wear. The cheaper the car, the lower quality they probably are, so they might wear faster in cheap cars. There's no solution to this except to try to learn downshifting to second gear from third with double declutching which might reduce the synchronizer wear, but once the synchronizers are worn, there's no solution since you would need a replacement gearbox which is expensive, or synchronizer overhaul which is equally expensive. However, if you learn to tolerate this, you can get lots of miles from your vehicle. The shift happens, it's just slow.

You can continue driving the car. This is not fatal. Just learn to avoid its deficiencies. I suspect you or the previous owner has beaten the hell out of the second gear synchronizer. The shift to first gear is probably supposed to be hard occasionally, even in a new vehicle. Only if you fail three times in row to shift to first gear, between each shift you obviously shift to neutral and momentarily release the clutch, then would I be worried.