Manual 6 Speed issues...con't - JKowners.com : Jeep Wrangler JK Forum
 
LinkBack Thread Tools Display Modes
post #1 of 9 Old 03-05-2009, 05:06 AM Thread Starter
Wheeler
 
Join Date: Nov 2008
Posts: 11
Feedback: 0 reviews
Manual 6 Speed issues...con't

Well finally had a chance to bring our Jeep to the dealer to have the service manager road test it and troubleshoot the transmission. It was a tech that took my wife out in it and she quickly noticed that he was shifting at above 3000 RPM between 1st and 2nd (that is where we were having issues with rough shifting) My question to all... Is that normal? cause it sure shifts better but sounds like the piston are gon'a let loose! Were used to shifting a little over 2k. Oh he says were going to get better gas mileage by shifting at a higher RPM? Any thoughts apprieciated!
Retrocouple is offline  
Sponsored Links
Advertisement
 
post #2 of 9 Old 03-05-2009, 05:11 AM
Granite Guru
 
Preacher's Avatar
 
Join Date: Feb 2009
Location: Miami, FL
Age: 53
Posts: 401
Feedback: 0 reviews

I am curious about the replies you are goig to get here...

My jeep isn't quite 2 weeks old and I have been experimenting with the shift points, trying to figure out where the jeep prefers to be shifted.

In my Vette, I shift at around 2K if I want to keep the gas mileage down, but the real power is not until you cross 3500 all the way till just this side of redline.

In the Jeep, it seems like the power band kicks in at about 2800 or so and pulls through 4K, but it doesn't seem to have any issues shifting early.

What kind of issues are you having when shifting at 2K?

--------------------
Preacher
REDRUM
2009 Wrangler 'X'
Preacher is offline  
post #3 of 9 Old 03-05-2009, 05:24 AM
Granite Guru
 
Duffy's Avatar
 
Join Date: Feb 2009
Location: South Shore, MA
Age: 57
Posts: 137
Feedback: 0 reviews

I'm not sure what you mean by "rough shifting" or "shifts better over 3000 rpm" I typically shift around 2500rpm for just plain ol' getting up to speed. If I need a little more pep, I'll go over 3000 to keep the rpms up to quickly go to the next gear. (Like to get up to speed to merge into highway traffic). Did the tech tell you everything was ok? What gear ratio are you running?
Duffy is offline  
Sponsored Links
Advertisement
 
post #4 of 9 Old 03-05-2009, 05:43 AM
Super Moderator
 
StubEXrube's Avatar
 
Join Date: Jun 2008
Location: Austin Texas
Posts: 15,341
Garage
Feedback: 5 reviews

if its shifting rough, thats not normal. When i am shifting correctly thru all gears, my 6 speed is very smooth. You should not feel as if the engine is having to rev. My first manual trans jeep took a while to get used to in terms of when to shift, but that was due to driver trial and error. My jk has never felt rough or idling high. stock gearing and stock tires/ now with 4:88 gears and 35" tires....has always performed flawlessly.
StubEXrube is offline  
post #5 of 9 Old 03-05-2009, 05:58 AM
Newbie
 
Join Date: Sep 2008
Age: 64
Posts: 5
Feedback: 0 reviews
Shift RPM's

The v6 in the JK likes rev's, When driving I try to keep engine RPM around 2000 or higher, let the engine spin for a shift your not going to hurt it. 6th gear for me is an Interstate only use 70 Mph or higher. Driving and watching the fuel economy meter I noticed my fuel economy goes up (I average around 20 MPG) vs driving and lugging the engine. Rpm's up better oil circulation and coolant circulation also. Remember your not driving a tractor.
TRJeff is offline  
post #6 of 9 Old 03-05-2009, 06:01 AM
 
Join Date: Jan 2009
Posts: 114
Feedback: 0 reviews

Hey Stub I have 5 grand on the speedo now and it took about 1500 to get the shifting lined out. Mine is extremely smooth now, but my wife used to complain at first. I learned how to drive it better, I think that may be the issue. I shift at or below 2500 RPM for better mileage, no so much rev, etc.. I really do not think that it is a dealership issue. By the way, how is your Jeep? You finally gotten straightened out?
dcj090 is offline  
post #7 of 9 Old 03-05-2009, 08:15 AM
Super Moderator
 
StubEXrube's Avatar
 
Join Date: Jun 2008
Location: Austin Texas
Posts: 15,341
Garage
Feedback: 5 reviews

Quote:
Originally Posted by dcj090 View Post
Hey Stub I have 5 grand on the speedo now and it took about 1500 to get the shifting lined out. Mine is extremely smooth now, but my wife used to complain at first. I learned how to drive it better, I think that may be the issue. I shift at or below 2500 RPM for better mileage, no so much rev, etc.. I really do not think that it is a dealership issue. By the way, how is your Jeep? You finally gotten straightened out?
dcj090- Yep it is up and running better than ever. no frame damage and lots of upgrades along with the repairs (rear track bar brkt, 4:88 gears, pro-cal, poly stabilizer, poly draglink, etc). Thanks for asking.

I still feel that although there is a period of break in, and that the engine needs to rev a little as to keep it from stalling, that the symptoms described (rough shifting and feeling like the pistons are gonna let loose) is not normal. If the service tech sees no issues w/ it then maybe it is driver error.
StubEXrube is offline  
post #8 of 9 Old 03-05-2009, 08:28 AM
Granite Guru
 
gt3073b's Avatar
 
Join Date: Aug 2007
Location: Lakemoor, IL (northwest Chicago burbs)
Posts: 453
Feedback: 0 reviews

This engine really does better with a few more RPMs. My brother-in-law was driving his 2 door rubicon like it had the old 4.0L I-6 engine, shifting at low rpms. I get mine up past 3000 rpm pretty regularly. He coudln't believe how much better mine handled when he rode with me even though it is a heavier 4dr with a lift, bumpers, and winch. We both have the same tires and gears, but my shift point was higher.

Also, you only get better mileage from low rpms if you aren't having to mash the gas to maintain speed. You'd do a lot better running 1/4 throttle at 2500 rpm vs wide open at 2000 rpm.

Keep in mind, peak torque is at 4000 rpm and peak horsepower is at 5000. Don't run it up there all the time, but the tach goes up there for a reason.

Bryan.

2007 JK Rubicon Unlimited Rescue Green 6 Speed
Mods Shrockworks Rails & Bumpers, Currie Lift, Tom Woods 1350 driveshafts, 35" Toyo M/Ts on ProComp 7028s
In Progress
To Do
gt3073b is offline  
post #9 of 9 Old 03-05-2009, 07:18 PM
Granite Guru
 
Join Date: Apr 2008
Location: W of Ft Worth
Posts: 236
Feedback: 1 reviews

has anybody tried an additive such as Z Max (I think) to smooth up shifting? Just curious.
cowboy49 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JKowners.com : Jeep Wrangler JK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome