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Discussion Starter #1
Alright, so I've had my 2012 JKUR 6-speed for 3 months now and I've gotten pretty good at shifting, but I still have not mastered the craft. I need help with one issue (without people dumping in me for not being a pro, lol).

So here is my issue: shifting from 1st to 2nd (and sometimes 2nd to 3rd) usually results in a slight jerk the second the clutch is fully released. I've tried going by the speed recommended in the owners manual, shifting at a lower RPM (2300 or so), shifting at a higher RPM (2900 to 3100), shifting quickly, shifting slowly, accelerating more before the clutch is fully released... you get the point. The only thing that seems to alleviate the jerk is when I wait a bit longer to release the clutch fully - about one second to be exact. I know that will result in premature wear of the clutch, but the jerk is annoying.

It doesn't happen all the time, though... down hills - no jerk; first thing in the morning - same; shifting exactly at the recommended speed at exactly 2600 RPM - works about 1/2 the time.

I'm thinking it's more user error since this is my first stick. Does anyone have a recommendation?
 

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Meh, my new 13 now has 5k miles, still does it, and sometimes it's almost like it's inconsistent....it happened just every rate now and then, I just smile and remind myself it's more fun than the auto I traded for it......the clutch system sucks ass, worse than any manual I've driven yet, and that includes a Samuari....don't think the drive by wire/computer crap helps either, sometimes it seems to stall before going WOT.....oh well, it's a jeep....forgettaboutit
 

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Random Dude
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Cochepaille,

I'm not entirely sure what you mean by a jerk upon clutch release - is the vehicle lurching forward slightly?
If so, just let off the gas until the clutch is fully engaged, then resume your acceleration.
(Accelerate through first, let off the gas as you clutch in, shift to second, let clutch out smoothly, resume acceleration.)

If the jerk is the vehicle decelerating, just feather the gas pedal a bit more as you release the clutch.

Did I win? :bounce:
 

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Discussion Starter #6
Cochepaille,

I'm not entirely sure what you mean by a jerk upon clutch release - is the vehicle lurching forward slightly?
It's hard to explain - it almost feels like the clutch pressure plate bounces off the flywheel. The Jeep doesn't just lurch forward, otherwise I would simply refrain from accelerating so much... it jumps forward a bit and then bounces back, which is why I don't know what to do.
 

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Slip the clutch a little more and you may have to get back on the throttle a little sooner than you think you would due to the throttle response lag.

Try not using the clutch. The JK manual is very easy to shift without pushing the pedal.
The guy is having a hard time getting a smooth shift, I wouldn't expect trying to shift without the clutch go very well..
 

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Random Dude
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The clutch is designed to get you going from a stop and engage the drivetrain, once you are moving you can shift gears without it during normal driving.
OK, technically true and totally provable, but NOT the first, go-to solution for a dude who's trying to master gear changes via the traditional, overwhelmingly widespread method.
I made mostly clutchless upshifts in my '65 Mustang with a burly 4 speed, so I get what you're saying.
But really, this requires a good understanding of the relative speeds of the the geartrain components so, REALLY? This is what you want him to try next?

If you're just opinionated and stubborn, I can respect that.
If you're messing with the guy looking for help, that's a bit of a dick move. (also respectable:D)



Cochepaille,
thedirtman has a valid point that's worth understanding after you figure out your current question, but Goody's pointing you where you need to go.:shitstorm:
 

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I am not trying to be stubborn, I guess it comes from my truck driveing days, you almost never use the clutch except for starting from a dead stop. Most of the vehicles I have owned have been manuals and I generally shift without using the clutch. Its not hard to do and saves wear and tear on the clutch. It all has to do with RPM's just like shifting with the clutch requires.

Dumping the clutch at the wrong rpm sounds what the op is having problems with. Knowing the shift points is important in any manual and having the engine running at a fast enough speed to handle the new gear is what you need to master. With the JK I would say that you need to have the rpm's up around 2800-2900 when making the shift. That way you have the power to engage the new gear without the engine lugging down due to lack of power. I would not use the throttle again until the clutch was fully engaged after the shift.
 

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Does anyone have a recommendation?
Yes. Forget what the book is telling you about shift points. Go about it in a slow, deliberate manner. Don't wind it out, it's not a race car. In fact, just barely get the thing rolling into the RPM while not going so slow as to having it lug the next gear. You will find the RPM range that suits your ability on your own. Once you can do it smoothly at your rate, you should have a sense of the intervals between the gears. You also need to have a sense of the time it takes for the engine to wind down from various RPM. Going faster can make for a smoother shift but it won't teach you anything.
It is NOT the same RPM drop for each subsequent shift, particularly, 1-2 and 2-3. If you can get a feel for that, you will be well on your way towards losing the amateur status. (No slam intended).

Don't dump the clutch peddle, use a two step approach to the pedal release.
First step takes out the slack.
Second step, with a little more finesse than taking out slack, smoothly transitions to full engagement.
Blend those two steps together for a single fast-slow motion.

The jerking is mismatched throttle. Tell your right foot to STFU until it knows what it's talking about. ;)

The goal is matching RPM between the engine, the gear and the road speed. Then you can do clutchless shifts.

Your feet aren't the only adjustable variables. Cold transmissions don't want to shift. Allow them the courtesy to warm up before trying to force the shifter, which means, your hand is also part of the equation.

Do it all deliberately at a relaxed pace, both you and the Jeep.
Going slow = Smooth.
Smooth = Fast.
Gotta go slow to go fast.
 

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I've owned a bunch of manual transmission cars and trucks, and even though I think my 2013 JK is one of the easier manuals to drive, it is one of the more difficult ones to drive smoothly. The 1st to 2nd klunker shifts were really bad and embarrassing when it was new, but seems to have settled down as it broke in and I refined my technique.

Mine shifts smoothest at around 3K RPM, but don't always feel like winding it out from a stop. I thought the jerking and noise just felt like u-joint slop/driveline lash. I still regularly goof it and get a jerky 1-2 or even 2-3 shift.
 

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On a previous vehicle I had similar problems and I would try to give it just a smidge of gas mid shift to keep the rpms up.... but it also only worked part of the time. I ended up upgrading manual transmission fluid to redline which helped a little. Not sure if there is a better option for manual transmission fluid for a JK that might alleviate the problem. Hope this helps.

Sent from AutoGuide.com App
 

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Discussion Starter #16
Thanks for all the recommendations everyone. It looks like I might be doing the right thing after all... feathering out the clutch for a split second longer, or as funfred put it, taking a 2-stage approach. As I mentioned before, my only fear in that approach is premature clutch wear. I guess slipping the clutch for a split second longer can't be that bad, though.

As for the clutch-free shifts, I think I'll hold off on those until I'm 100% confident in my clutching abilities, although I know I'm close as my up-shifts after 2nd fall into place as smooth as butter and feel as though the clutch isn't needed. I think 1st to 2nd is always going to be tricky, though... the Jeep takes off like a raped ape after 1500 rpm, which makes it tricky to match the rpms.
 

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Never would have thought to describe the acceleration of a JK as raped ape but ok.
 

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Going from 1st to 2nd is always a little rougher...either waiting for higher rpm, or tapping the gas a little before letting out of the clutch works the best
 

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As I mentioned before, my only fear in that approach is premature clutch wear. I guess slipping the clutch for a split second longer can't be that bad, though.
Using your clutch to hold you at the stoplight on an incline is what leads to premature wear. A slight slippage while shifting is what they're designed to do, for tens of thousands of miles.
Unless you really suck at it, don't sweat it. It'll be fine.
 

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I have to agree with folks saying two different things... throttle lag and clutch/gas feathering.

Don't feel too bad about it as a new/infrequent manual driver. I have been driving manual shift tractors, motorcycles and automobiles for 37 years. I still occasionally have the same experience with my JKU when shifting from 1st to 2nd.

When you make the shift, don't completely release the gas pedal to keep the TPS and computer engaged and once you feel the clutch start to grab, let the clutch out a little slower as you start to give it more gas.

It sounds like you are really close. The changes I am recommending are likely extremely subtle compared to what you are currently doing.

Regardless of what works for you, once you get it right, even one time by mistake... try to replicate that action and keep practicing what you did to make it smooth. Its all repetition.
 
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