[mtoo]

For you MT drivers, why is it that when I try to downshift from 3rd gear to 2nd gear, occasionally the transmission blocks me from putting the car in that gear?

I can understand if it was preventing me from money shifting, but it happens at all sorts of slower speeds that would not cause the RPM to jump over the redline.

Example 1: Getting onto a highway in 3rd at like 30-40mph, and trying to drop to 2nd gear to accelerate into traffic.

Example 2: Driving 30-40mph in 3rd gear approaching a school zone, and then wanting to downshift into 2nd to slow down.

Both of the above situations never seem to work unless I double declutch, but by that point in time I've already spent seconds trying to get the thing in gear.

If I turn off rev match, it does not block me from going into gear in those situations anymore, and the syncros or throttle blip works fine to keep me moving (although less convenient).

What gives?

[ixD9]

There's no lockout in the transmission that would prevent you from shifting into second. Are you maybe being too aggro with the shift lever? Syncros need time to match so it's best to just exert a bit of pressure and let it slip into gear versus trying to jam it into gear as fast as possible. If you're way too aggressive you can even bend the shifter fork which could cause issues with shifting until you get it straightened back out.

[Squidget]

Originally Posted by ixD9

There's no lockout in the transmission that would prevent you from shifting into second. Are you maybe being too aggro with the shift lever? Syncros need time to match so it's best to just exert a bit of pressure and let it slip into gear versus trying to jam it into gear as fast as possible. If you're way too aggressive you can even bend the shifter fork which could cause issues with shifting until you get it straightened back out.

This. There's no intelligence/nannies in the MT, if you are being blocked it's a physical component getting jammed somewhere it's not supposed to be.

I guess it's also possible your synchros have a defect, but if the 2nd gear collar was messed up, I assume* you'd feel it on 1 -> 2 shift, also.

*disclaimer: very much not a mechanic.

[mtoo]

Originally Posted by ixD9

There's no lockout in the transmission that would prevent you from shifting into second. Are you maybe being too aggro with the shift lever? Syncros need time to match so it's best to just exert a bit of pressure and let it slip into gear versus trying to jam it into gear as fast as possible. If you're way too aggressive you can even bend the shifter fork which could cause issues with shifting until you get it straightened back out.

I don't think I'm being too aggressive, so when it 'blocks' me from engaging 2nd gear, I don't force the issue. I never have trouble going from 1st to 2nd gear.

So are we sure that Rev Match doesn't have any system in place that's causing this? Unless I'm imagining it, it seems to behave differently with Rev Match On vs Rev Match Off. I'll keep experimenting.

[robopp]

Originally Posted by mtoo

I don't think I'm being too aggressive, so when it 'blocks' me from engaging 2nd gear, I don't force the issue. I never have trouble going from 1st to 2nd gear.

So are we sure that Rev Match doesn't have any system in place that's causing this? Unless I'm imagining it, it seems to behave differently with Rev Match On vs Rev Match Off. I'll keep experimenting.

Rev match just blips the throttle. Not sure about BMW, but Porsche has sensors to know what gear you’re in and uses that to apply throttle. The actual shifting is purely mechanical.

[aerobod]

Originally Posted by robopp

Rev match just blips the throttle. Not sure about BMW, but Porsche has sensors to know what gear you’re in and uses that to apply throttle. The actual shifting is purely mechanical.

The G87 has a gear sensor on the top of the manual transmission.

[RockCrusher]

Your experience is quite the opposite of mine with shift assist on.

Down shifts -- but of course avoiding shifts approaching money shift territory -- and up shifts were a real nice experience with my 2023.

So not sure why you are experiencing what you report.

Are you sure you have shift assist on? If you switch keys the settings you may be used to with the other key may not be the same settings the 2nd key supports. I had to work to get the same settings associated with both keys. Or if I used the key that was not associated with my driver ID I would sign in -- with a PIN -- to get all the benefits provided by my driver ID.

With shift assist I do recall I couldn't take my time. For downshifts in particular. The rev matching bump in RPMs is rather brief.

[mtoo]

All right, I think I figured it out. I'm just an idiot....for over a year now.

In situations when I want to downshift quickly, I am pushing the stick too far to the left and down. In other words, if I pushed up instead of down, it would go into reverse. But down, there's no where to go.

I think I've been driving MT's with R on the other side of the shifter for so long that I never even considered this.

I'm attaching a picture to illustrate where I have been putting the shifter when I'm trying to react quickly, and I was getting 'blocked'.

The reason I did not have this problem with Rev Match off is because I was much more aware and precise with shifting and manually rev matching.

[Squidget]

Originally Posted by mtoo

All right, I think I figured it out. I'm just an idiot....for over a year now.

The best possible outcome! You don't have to pay a mechanic to fix something when you were just being an idiot.

Back when I owned a Celica and accidentally bumped the child safety button I didn't know existed, and then wondered why my windows wouldn't roll down. The mechanic came out and said "you are gonna feel mad at yourself" and showed me the button.

Best outcome! It only cost me the tip to the mechanic. I'm sure we all have stories like this, you are not alone.