What does it mean to have a stiff first gear?

Question

This problem is a small one and it can only occur with manual cars, but I have been curious to find out more about it for a while now. Sometimes, when the car is attempting to pull away from a standstill (at traffic lights, for example) the driver will put the clutch down and try to put it in to first gear. They either have to exert more force than most would feel comfortable in doing to force it in to first gear or try again and it will usually go in the second time. A few cars that I have driven or been a passenger in in the past have had this problem.

It also happened with the reverse gear (as well as first) on my old car, but I would need to lift the clutch just a little from the pedal down position in order to move the gear stick fully in to the reverse gear. To get it in to first I just had to use a bit more force than the manufacturer intended.

I wonder if the problem occurs primarily with first gear because that is the one that is used the most. I have only noticed this issue on older cars (10+ years).

What is the gearbox doing mechanically when the car won't go in to first with the clutch pedal down?

Is it going to lead to a damaged gearbox or have any other bad knock-on effects?

Answer 1

After reading the op's question again, following being prompted to by the comment below from @Gargravarr, I realised I needed to update this answer.

I believe that the real reason that selecting 1st can be difficult while the car is stationary is due to the way in which the locker ring in the syncromesh operates. The locker ring is designed to stop a gear being selected until speed of the gears have been fully synchronised.

The selector ring is normally rotating at a speed relative to the vehicle speed, which is due to the selector ring being connected to the output shaft. When the selector ring pushes against the locker ring, the locker ring is able to start rotating and position itself correctly to mesh with the selector ring. However, when selecting first gear while stationary, the selector ring will not be turning and so if the teeth of the selector ring and the blocker ring do not align sufficiently to allow them to mesh, resistance will be felt in the gear selector. Pushing harder on the selector will force the blocker ring to move a little and aid alignment.

When this happens, allowing the car to move slightly will usually aid alignment and allow the gear to select easily.

So this resistance to selecting first gear is nothing to do with a worn synchromesh, but is more than likely to do with the design of the locker ring and selector ring.

Here is a link to a video that describes how the locker ring operates.

---- Original answer below ----

1st and Reverse often don't have syncro clutches on the gears. A lack of these makes it difficult to select the gears while the car is moving. However they shouldn't make a difference when the car is stationary. There again, you probably never select the other gears while the car is stationary.

Additional by @Paulster2 - If the friction disk is spinning right after clutch release, it might make it harder to get it 1st/Reverse.

Answer 2

The answer I've been told, because my '85 Supra suffers from this, is that the synchro ring on first gear is worn. The ring is made of brass (a soft metal) to allow it to slip as the synchroniser brings it up to speed during a shift. Since first spins extremely fast relative to the output shaft, you can expect this synchro ring to take the most wear.

It can also be due to a worn pivot point on the end of the transmission shift lever, where it engages with the selector rods that move the cogs. Some companies make aftermarket pivots that restore or even enhance the 'feel' through the shifter of the gear engaging.

Since you're rarely in first for more than a few seconds, the wear on the synchro is not problematic.