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Old 12-18-2010, 05:35 AM   #1
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Question RPM drop

Why do the RPMs take so long to drop? It's so hard shifting from 1st to 2nd smoothly since shifting too quick makes the whole vehicle jerk forward. Is there some kind of modification you can do to fix this? I have never driven something that takes this long for the RPMs to drop. I hope the Pentastar fixes this problem.

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Old 12-18-2010, 07:48 AM   #2
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What RPM are you shifting at? Have you tried shifting at different points? I've never had any such issue. I've heard that the Pentastar will cure cancer.

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Old 12-18-2010, 08:58 AM   #3
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Did you try lifting your foot off the accelerator?
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Old 12-18-2010, 09:08 AM   #4
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I "think" the syncros are different for the first few gears but I don't think that's truly the problem. I've felt the same thing on my JK shortly after buying it. You have to feel the engagement points differently than other manuals it seems. My last manual Jeep was a Cherokee but it shifted smoothly between all gears. None of its gears felt any different through all changes. My JK does so between 2-3-4-5-6 but 1-2 is always a little hit or miss. I gotten used to shifting at the right place now for the first gear and its smooth as well.

Sounds like you may be letting go of your clutch a bit to soon or at the wrong point. There may also be to much gas involved too.
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Old 12-18-2010, 09:41 AM   #5
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Quote:
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Did you try lifting your foot off the accelerator?
I didn't think of that. Definitely not a "best practice".
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Old 12-18-2010, 09:46 AM   #6
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Quote:
Originally Posted by ESP123
Sounds like you may be letting go of your clutch a bit to soon or at the wrong point. There may also be to much gas involved too.
x2.

Assuming that there's no mechanical problems and/or you're not referring to when the Jeep is cold, you've just got to get the timing right. Your manual (available online at Jeeps website) will tell you the proper shift speeds, at which point you can tinker with the gas/clutch until you get the right mix.

If that doesn't work, you may actually have a mechanical problem. But I'm thinking not . . . .
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Old 12-18-2010, 05:03 PM   #7
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Nobody has commented on the RPM drop, which seems to be the main problem here for quick shifts. Seriously, if I rev this thing to 3k at operating temperature, it takes about 4-5 seconds for it to return to idle. The Liberty I used to drive did it in about 2 seconds.
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Old 12-18-2010, 05:15 PM   #8
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Originally Posted by Thracks View Post
Nobody has commented on the RPM drop, which seems to be the main problem here for quick shifts. Seriously, if I rev this thing to 3k at operating temperature, it takes about 4-5 seconds for it to return to idle. The Liberty I used to drive did it in about 2 seconds.
Could be because the Wranglers are designed for offroading and maybe the slower RPM drop was created to help when on the trail. Not sure really because I never really pay attention to em. I shift by the sound and feel of the road. Also, its different every time depending on how much acceleration I need or if I'm going up a hill.
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Old 12-18-2010, 05:30 PM   #9
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I have no idea what you might be experiencing. I have a 10 Rubi 6 spd. with no shifting/rpm issues.
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Old 12-18-2010, 06:26 PM   #10
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You rev to 3k and take your foot completely off the gas and it takes 4-5 seconds to drop below 1k? Something is wrong. Mine doesn't take anywhere near that long.
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Old 12-18-2010, 06:38 PM   #11
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Quote:
Originally Posted by daggo66
you rev to 3k and take your foot completely off the gas and it takes 4-5 seconds to drop below 1k? Something is wrong. Mine doesn't take anywhere near that long.
x2
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Old 12-18-2010, 06:53 PM   #12
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I've said this on another rpm post and no answer so it's probably not your problem either, but


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x2
Do you ever see the RED )Z( ICON, at first ignition, then it goes out and it will be to the left of the ESP ICON ???

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Old 12-18-2010, 08:06 PM   #13
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My gf 3.7l jeep liberty does the something if I rev it in n it will hold there for 3-4 secs I have never seen another vehicle that does this.
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Old 12-18-2010, 08:47 PM   #14
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My dads commander does that same thing. My mom's BMW drops fast tho. I think it is because jeep doesn't use lightweight flywheels. The heavier flywheel takes longer to slow the engine down. I'm not sure of the benefit of this flywheel but I know that the lightweight ones are for sports cars so it makes sense that you wouldn't put it in a jeep
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Old 12-18-2010, 10:40 PM   #15
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Ours has all of 75 miles on it so far, but it's an akward shift between 1st and 2nd also. I think with a little practice I'll get used to it. I think it has to do with the slow drop off in RPM as well. Doesn't take 4-5 seconds, but it does take too long. I've been driving manual transmissions for 30 years, I'm not the problem.
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Old 12-18-2010, 10:45 PM   #16
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30 years of driving cars or trucks?
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Old 12-18-2010, 11:16 PM   #17
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I have never had any problems with the shifting on my 6-speed Sahara, but I have noticed that the rpms do take longer to drop down to idle speed, clutch in or out, than on any manual transmission vehicle I have owned recently. I figured it was just a "jeep thing"--no biggie.
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Old 12-18-2010, 11:25 PM   #18
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30 years of driving cars or trucks?

Cars, trucks, tractors, commercial trucks, and several years with a 18 wheeler locally. I'm decent with a clutch.
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Old 12-18-2010, 11:27 PM   #19
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I have never had any problems with the shifting on my 6-speed Sahara, but I have noticed that the rpms do take longer to drop down to idle speed, clutch in or out, than on any manual transmission vehicle I have owned recently. I figured it was just a "jeep thing"--no biggie.
Agreed, no biggie, just a bit akward.
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Old 12-18-2010, 11:43 PM   #20
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Then you should get used to it quickly. I've driven cars and trucks and big rigs as well. I don't notice any issue and can't ever remember there was one. So either something is wrong with yours or you'll quickly adjust.
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Old 12-19-2010, 02:17 AM   #21
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Quote:
Originally Posted by Thracks View Post
Nobody has commented on the RPM drop, which seems to be the main problem here for quick shifts. Seriously, if I rev this thing to 3k at operating temperature, it takes about 4-5 seconds for it to return to idle. The Liberty I used to drive did it in about 2 seconds.

Hey I am having the same exact issue that you are stating it drives me crazy. The higher the revs the worse it is. I thought it might be because of the AC, but if no one is having the same issue as us maybe the actually is something wrong. I will ask around here, and see if anybody local is having the same issues here.

If I her anything, I will let you know I would appreciate the same if you gain any traction. BTW I have a 2010 with about 1500 miles on mine. It has been doing it since I bought it. I thought it might be normal for the Jeep but since no one but you is experiencing it now I am all of a sudden worried about it.
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Old 12-19-2010, 02:26 AM   #22
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Quote:
Originally Posted by Thracks
Why do the RPMs take so long to drop? It's so hard shifting from 1st to 2nd smoothly since shifting too quick makes the whole vehicle jerk forward. Is there some kind of modification you can do to fix this? I have never driven something that takes this long for the RPMs to drop. I hope the Pentastar fixes this problem.
If it bothers you so much for that jumpy feeling when it goes down... GO UP when im in a big hurry im not gonna wait for my rpms to drop, hit the gas that'll give you a smoother shift to and i know what your talking about,
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Old 12-19-2010, 02:30 AM   #23
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^ wait, we're just talking about normal travek arent we?
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Old 12-19-2010, 02:36 AM   #24
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Oh, boy, a subject comes up in a thread and worry, worry, worry.

Quote:
Originally Posted by Thracks View Post
Nobody has commented on the RPM drop, which seems to be the main problem here for quick shifts. Seriously, if I rev this thing to 3k at operating temperature, it takes about 4-5 seconds for it to return to idle. The Liberty I used to drive did it in about 2 seconds.
Well, I have noticed that this jeep doesn't perform like a sports car...shizzel.

When I quickly got over that, I was fine.

Here is some things that I have taken notice of. The RPMs on mine is not responsive of the skinny pedal...I've learned patience.

It shifts very much like the S10 truck that I owned. The jeep drives more like a truck than my truck did...I like that. It's suspension is much more stiff and it could probably drive right over the S10...I like that...it is a rugged vehicle...much more than any that I have driven...a lot to like.

A post above mentioned a weighty fly wheel...that may explain the length of time for RPM response.

Another issue that I find with response of the vehicle is in down hill low gear usage to reduce or keep the speed under control. The jeep doesn't seem to do this well. I'm guessing lower compression makes it that way...I've gotten used to that too, I grab the next gear down. Even steep hill descending in 4 low, first gear is pretty slow, especially on a Rubicon....problem solved. This jeep has so many gears...12 forward speeds, it is hard to argue with it.

I don't think your jeep is different from mine. Adjust.
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Old 12-19-2010, 01:12 PM   #25
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I'll post again on this; 10 Rubi 6spd w/stock muds, off road bumpers front and rear w/winch and absolutely no problems with rpm's hanging up, shifting in general (extreme cold or hot), up hill, down grades, etc. it just works without any issues and if I didn't know better I would never believe it's fly by wire. Maybe some were built when the stars lined up.
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Old 12-19-2010, 01:22 PM   #26
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I have a question for the guys complaining about the slow rpm drop. Where would you like it to drop to? I paid attention for the first time this morning. Shifted at about 3K, by the time I was releasing the clutch it had dropped to 2k. I completed the shift as smooth as ever. Then I started thinking. If the RPM had dropped any lower the engine would be lugging.

Those of you who have been driving manuals for a 100 years or whatever it is, should know that if you get you RPM's to the right level you can shift without a clutch. If it's too high or too low, it won't work.
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Old 12-19-2010, 02:58 PM   #27
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Quote:
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I have a question for the guys complaining about the slow rpm drop. Where would you like it to drop to? I paid attention for the first time this morning. Shifted at about 3K, by the time I was releasing the clutch it had dropped to 2k. I completed the shift as smooth as ever. Then I started thinking. If the RPM had dropped any lower the engine would be lugging.

Those of you who have been driving manuals for a 100 years or whatever it is, should know that if you get you RPM's to the right level you can shift without a clutch. If it's too high or too low, it won't work.
Tom,

On my Jeep the higher the rev the longer it stays up. I don't think we want it necessarily to go down to any specific RPM just want it to go down. So if you drive yours and shift at 3K and it goes down to 2K then there is definitely something wrong with mine. If I shift at 3k then it will stay at 3K for the duration of the shift. This makes the shifts clunky. The lower the RPM the smoother the shift so

If I do shift at 3k and wait an additional 3 seconds the RPMs will finally drop enough for a smooth shift. It is annoying, but as a poster indicated earlier, I thought it was a newer Jeep thing, none of my older Jeeps did it. So if you are saying that yours doesn't do it there is definitely something wrong with mine.
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Old 12-19-2010, 04:21 PM   #28
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Tom,

On my Jeep the higher the rev the longer it stays up. I don't think we want it necessarily to go down to any specific RPM just want it to go down. So if you drive yours and shift at 3K and it goes down to 2K then there is definitely something wrong with mine. If I shift at 3k then it will stay at 3K for the duration of the shift. This makes the shifts clunky. The lower the RPM the smoother the shift so

If I do shift at 3k and wait an additional 3 seconds the RPMs will finally drop enough for a smooth shift. It is annoying, but as a poster indicated earlier, I thought it was a newer Jeep thing, none of my older Jeeps did it. So if you are saying that yours doesn't do it there is definitely something wrong with mine.
I think it's too easy to say it's a "Jeep thing". As I posted, my 10 Rubi 6 spd. is fine. The rpm's normally drop down when I shift to where I think it should without any issues. If you're shifting, let's say at 2,500 or 3,000 rpm and it stays there for almost 3 sec. then I have to say something is definately wrong. It might be as simple as a computer re-flash. What you can do without a dealer visit that won't hurt anything is to disconnect your battery for at least 10 minutes and then re-connect and see how it is. If it still persists and you bring it in they shouldn't say it's normal. If they do, check out another 6 spd. JK that's on the lot and see how that is.
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Old 12-19-2010, 04:32 PM   #29
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Quote:
Originally Posted by adrenaline

Tom,

On my Jeep the higher the rev the longer it stays up. I don't think we want it necessarily to go down to any specific RPM just want it to go down. So if you drive yours and shift at 3K and it goes down to 2K then there is definitely something wrong with mine. If I shift at 3k then it will stay at 3K for the duration of the shift. This makes the shifts clunky. The lower the RPM the smoother the shift so

If I do shift at 3k and wait an additional 3 seconds the RPMs will finally drop enough for a smooth shift. It is annoying, but as a poster indicated earlier, I thought it was a newer Jeep thing, none of my older Jeeps did it. So if you are saying that yours doesn't do it there is definitely something wrong with mine.
The other day when it was 8 degrees out my 4.0 did the same thing. I would shift at 2100 from 1rst to 2nd and the tons just kinda hung at 2100 with no throttle and clutch pushed in. Freaked me out. Since then its back to normal. I normally shift at 2500 and it drops to 1800 or so and I supplement it with throttle as I release the clutch. It's a dance really.
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Old 12-19-2010, 04:34 PM   #30
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Quote:
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Tom,

On my Jeep the higher the rev the longer it stays up. I don't think we want it necessarily to go down to any specific RPM just want it to go down. So if you drive yours and shift at 3K and it goes down to 2K then there is definitely something wrong with mine. If I shift at 3k then it will stay at 3K for the duration of the shift. This makes the shifts clunky. The lower the RPM the smoother the shift so

If I do shift at 3k and wait an additional 3 seconds the RPMs will finally drop enough for a smooth shift. It is annoying, but as a poster indicated earlier, I thought it was a newer Jeep thing, none of my older Jeeps did it. So if you are saying that yours doesn't do it there is definitely something wrong with mine.
I would definitely say you have an issue that should be looked at. Good thing we hashed it out.

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