Rougher shift when short shifting?

[NiteScar]

Originally Posted by Ultramaroon

I'll guess that it's your clutch. Have I mentioned this thread? It leads into a DIY.

You did! I still need to look into doing something like this

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[humfrz]

Originally Posted by NiteScar

So I actually drive a 13-Speed big rig for a living and we call this floating gears! I did that for a few years and have been re-teaching myself to use the clutch proficiently for the last year; but for some reason I have the damndest time shifting my BRZ lol..

1st to 2nd is jarring most of the time and I cant figure out if it's my clutch release, or where the sweet spot for the RPMs should be. Granted I'm used to double clutching an un-syncro'd gearbox and I have QUITE a lot more time behind the wheel of my rig. Was afraid to try the clutchless shifting due to unfamiliarity with the gearbox and whatnot though.

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With the twin, I suggest you start by finding that sweet spot between 1st and 2nd at low speeds. At first I noticed a slight "gear meshing feel" if I didn't have it just right. Then I would speed up (or slow down) the shift speed until I felt it slip into 2nd with no feeling at all.


Now, if I could just remember not to try to take off at stop lights in 3rd gear …


humfrz

[NiteScar]

Originally Posted by humfrz

With the twin, I suggest you start by finding that sweet spot between 1st and 2nd at low speeds. At first I noticed a slight "gear meshing feel" if I didn't have it just right. Then I would speed up (or slow down) the shift speed until I felt it slip into 2nd with no feeling at all.


Now, if I could just remember not to try to take off at stop lights in 3rd gear …


humfrz

Hahaha I can't imagine trying to "throttle dance" with the clutch to start above 1st gear like I would in the big rig.

Now my experience with trucks is that EVERYTHING relies on RPMs. You have to rev match every and anything or it's just not happening. Miss a gear, rev match; downshift, rev match etc or you're gonna be hanging out in neutral all day.

So when you say low speeds, are you meaning specifically shift to 2nd way early (like almost right after you've fully engaged 1st)? Do you mean eco-driving and refraining from redlining every gear? ;D

I've tried playing around with shift points (all rpm based) to no avail. I admit my timing is off as others have mentioned in this thread and learn quite a bit from recommendations.

P.s. to OP: sorry that your car is behaving wonky and these continued replies don't necessarily remedy your situation.

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[humfrz]

Originally Posted by NiteScar

Hahaha I can't imagine trying to "throttle dance" with the clutch to start above 1st gear like I would in the big rig.

Now my experience with trucks is that EVERYTHING relies on RPMs. You have to rev match every and anything or it's just not happening. Miss a gear, rev match; downshift, rev match etc or you're gonna be hanging out in neutral all day.

So when you say low speeds, are you meaning specifically shift to 2nd way early (like almost right after you've fully engaged 1st)? Do you mean eco-driving and refraining from redlining every gear? ;D

I've tried playing around with shift points (all rpm based) to no avail. I admit my timing is off as others have mentioned in this thread and learn quite a bit from recommendations.

P.s. to OP: sorry that your car is behaving wonky and these continued replies don't necessarily remedy your situation.

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Yes, slow speeds, like gently moving through your neighborhood.

That way, if you miss it, you don't have people yelling out "grind me off a pound", or if you mess up, it won't destroy the transmission. -

When I was driving large trucks, back-in-the-day, my biggest screwups came when I couldn't remember which side of the axle (2 speed differential) I was in. -


humfrz

[NiteScar]

Originally Posted by humfrz

Yes, slow speeds, like gently moving through your neighborhood.

That way, if you miss it, you don't have people yelling out "grind me off a pound", or if you mess up, it won't destroy the transmission. -

When I was driving large trucks, back-in-the-day, my biggest screwups came when I couldn't remember which side of the axle (2 speed differential) I was in. -


humfrz

Hahaha I'll have to do more experimenting when the neighbors aren't home. I appreciate the tips!



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[Spec C Wannabe]

Originally Posted by humfrz

I'd like to expound on this concept.

To understand the "timing" of shifting a MT, I suggest you try this technique.

With the transmission warmed up learn to shift UP the gears WITHOUT using the clutch OR blipping the throttle.

Yes, use the clutch to put it into first gear, after the car gets going, let off the gas and slip the car into second gear (without using the clutch or hitting the throttle). Do the same from 2nd to 3rd and 3rd to 4th.

Once you "learn" the timing, by getting it "right", you should be able to shift up through the gears without feeling (or hearing) the gears mesh, without using the clutch.

After you have mastered this technique, shifting using the clutch is a snap.


humfrz

To be honest, I have tried clutchless shifting 1st - 2nd for a few times but the transmission didn't allow my gear stick to move from 1st to neutral. There were some kind of force to hold it to 1st. I am gutless to yank it out of 1st fear of ruining my feeble transmission.

[Ultramaroon]

Originally Posted by Spec C Wannabe

To be honest, I have tried clutchless shifting 1st - 2nd for a few times but the transmission didn't allow my gear stick to move from 1st to neutral. There were some kind of force to hold it to 1st. I am gutless to yank it out of 1st fear of ruining my feeble transmission.

The hub sleeve which slips between gears - first and second in this case - has a shape which matches up with the dog teeth on the gears. The angle is such that whenever there's torque in either direction, the sleeve gets sucked into the gear. That's the force you're fighting.

[humfrz]

Originally Posted by Spec C Wannabe

To be honest, I have tried clutchless shifting 1st - 2nd for a few times but the transmission didn't allow my gear stick to move from 1st to neutral. There were some kind of force to hold it to 1st. I am gutless to yank it out of 1st fear of ruining my feeble transmission.

Well, if your car doesn't want to easily come out of 1st without using the clutch, don't force it.

Oh yes, I don't believe that this transmission if "feeble" nor "made out of glass" as long as one doesn't try to put more power through it than it was designed to handle and one doesn't "beat on it".

If I, and some others, can consistently and smoothly shift up through the gears with this transmission without using the clutch - most people should be able to do that while using the clutch -

Timing is everything. -


humfrz

[Ultramaroon]

Originally Posted by humfrz

Timing is everything. -

It really is.

[ermax]

Originally Posted by Spec C Wannabe

To be honest, I have tried clutchless shifting 1st - 2nd for a few times but the transmission didn't allow my gear stick to move from 1st to neutral. There were some kind of force to hold it to 1st. I am gutless to yank it out of 1st fear of ruining my feeble transmission.

As Ultramaroon said, the sleeves lock to the gear when there is load. You can’t easily pull the sleeve into neutral unless there is zero load. Load doesn’t have to be positive either. If you are decelerating it will apply negative load.

[Capt Spaulding]

I wouldn't recommend clutchless shifting as a matter of habit. If you're intent on doing it and you can't get the tranny out of first on overrun try preloading the shifter and easing off the accelerator. It should drop out of first as soon as the transmission is unloaded. The move out of a gear is similar to clutchless shifting a constant mesh sequential gearbox (e.g. motorcycle). The key is unloading it.

As to getting from 1 - 2 smoothly at low speed, I've had the best luck moving the shifter quickly, but with minimal force. For reasons I can't explain the first-second sychronizer likes lots of foreplay at low speed. Move the shifter out of first quickly and then gently apply pressure to get it to slip into second. You'll feel resistance going into second, patience is your friend.

[churchx]

Well, 1st & 2nd synchros ARE different to rest, IIRC triple cone (for lasting longer with with higher torque due gearing at these gears? Or due gearing ratio differences of first gears and thus more rpm difference to even out?) vs single cone synchros for other gears. But then again many cars have such combination, and for many other cars there is little if any difference in engaging first gears, so i guess that's not an excuse.

[jcw99]

Originally Posted by NiteScar

Hahaha I'll have to do more experimenting when the neighbors aren't home. I appreciate the tips!



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Go to the home page of member PandaSPUR and read his method in his post of May 18, 2017. It worked for me right away. All I had to do was step on the throttle a bit sooner when shifting to second. I too drove trucks and I have a hard time not 'bumping" an imaginary governor sometimes. When I started driving trucks the operating range was mostly 1600 to 2100. Then on the Maxidyne 5 speeds that came out in Nov. of '66 it was 1200 to 2100. The last truck I drove it was 1200 to 1800. Time marches on but we sometimes have trouble getting rid of old patterns in our heads. Good luck!

[Ultramaroon]

This one?

Originally Posted by PandaSPUR

In which direction is the jerk?

If car jerks forward (you get pushed into the seat), give less RPM when you shift.
If car jerks backwards (you get pushed forward), give more RPM when you shift.