3000 RPMs at 60 mph. Need Help. - JK-Forum.com - The top destination for Jeep JK Wrangler news, rumors, and discussion

Notices
Modified JK Tech Tech related bulletin board forum regarding subjects such as suspension, tires & wheels, steering, bumpers, skid plates, drive train, cages, on-board air and other useful modifications that will help improve the performance and protection of your Jeep JK Wrangler (Rubicon, Sahara, Unlimited and X) on the trail.

PLEASE DO NOT START SHOW & TELL TYPE THREADS IN THIS FORUM

3000 RPMs at 60 mph. Need Help.

 
Old 02-21-2019, 06:38 PM
  #1  
JK Newbie
Thread Starter
 
Join Date: Feb 2019
Location: Apple Valley
Posts: 3
Thanked 0 Times in 0 Posts
Red face 3000 RPMs at 60 mph. Need Help.

Hello Jeep world, I am new to this Jeep universe. A couple of months ago I purchased a 08 sahara unlimited. The jeep came stock besides having 35's, with no lift. The issue I am having is that my jeep feels really forced when driving ( sluggish ) , maybe its because of the 35s, on stock gears. At 60 mph my rpms are pushing to 3000 rpm on 6th gear. The jeep has a manual trans as well. I also just put in a 4'' lift as well. Or is this normal for 35's on a 4'', on stock gears. Thank you for your time I appreciate it.
MrCuevas08 is offline  
Old 02-21-2019, 06:46 PM
  #2  
Super Moderator
 
BoraBora's Avatar
 
Join Date: Mar 2015
Location: McLean, VA
Posts: 589
Thanked 26 Times in 25 Posts
Default

6th gear, 35's, 3.8L, 3000 RPM @ 60 MPH? No, sounds like you have aftermarket gears...likely 5.13's. 6th wouldn't even be usable for you with stock gears and 35's.
BoraBora is offline  
The Following User Says Thank You to BoraBora For This Useful Post:
MrCuevas08 (02-21-2019)
Old 02-21-2019, 06:53 PM
  #3  
JK Newbie
Thread Starter
 
Join Date: Feb 2019
Location: Apple Valley
Posts: 3
Thanked 0 Times in 0 Posts
Default

Oh okay yeah I didn't know that, thank you i appreciate it. You would recommend me to stay at this gear ratio? My jeep is my commuter vehicle, to work and back. Go off roading every other weekend to be honest.
MrCuevas08 is offline  
Old 02-21-2019, 06:56 PM
  #4  
Super Moderator
 
BoraBora's Avatar
 
Join Date: Mar 2015
Location: McLean, VA
Posts: 589
Thanked 26 Times in 25 Posts
Default

Originally Posted by MrCuevas08 View Post
Oh okay yeah I didn't know that, thank you i appreciate it. You would recommend me to stay at this gear ratio? My jeep is my commuter vehicle, to work and back. Go off roading every other weekend to be honest.
Thatís a personal preference really. With a 3.8L though, 5.13ís seem to be what everyone prefers as it needs all the get-up-and-go it can get.

Iím a little confused though, you say the Jeep is sluggish? However, itís at 3k RPM @ 60 MPH in top gear? It should feel really peppy.
BoraBora is offline  
The Following User Says Thank You to BoraBora For This Useful Post:
MrCuevas08 (02-22-2019)
Old 02-21-2019, 07:06 PM
  #5  
JK Jedi Master
 
Join Date: Jan 2008
Location: Texas
Posts: 10,856
Thanks: 0
Thanked 35 Times in 35 Posts
Default

Wouldn't hurt to verify the current gear ratio, as 3000 @ 60 seems more like 5.38's?. You can lift one end, then spin a tire while counting driveshaft revolutions. Or pop the diff cover and count teeth.

4.56 and 4.88 are fairly popular for 3.8 6-spds on 35's. But with the cost of regearing, spending some time on research and opinions is a good thing. Here is a chart on ratios and rpms so you can get an idea of where the different ratios will put you. Measure the tires (don't just use 35")


Last edited by nthinuf; 02-21-2019 at 07:09 PM.
nthinuf is offline  
The Following User Says Thank You to nthinuf For This Useful Post:
MrCuevas08 (02-22-2019)
Old 02-22-2019, 04:35 AM
  #6  
JK Freak
 
icrashbikes's Avatar
 
Join Date: Dec 2011
Location: NJ
Posts: 581
Thanks: 0
Thanked 12 Times in 12 Posts
Default

I'd bet by 'sluggish' OP means that low gear feel. Like a dump truck. It winds up quickly in between gear changes and top reasonable speed is in the 60s. I say put 37's on it to fix the ratio
icrashbikes is offline  
The Following User Says Thank You to icrashbikes For This Useful Post:
MrCuevas08 (02-22-2019)
Old 02-22-2019, 07:43 AM
  #7  
JK Enthusiast
 
jordy's Avatar
 
Join Date: Nov 2015
Location: Phoenix, AZ
Posts: 394
Thanked 3 Times in 3 Posts
Default

Originally Posted by MrCuevas08 View Post
You would recommend me to stay at this gear ratio? My jeep is my commuter vehicle, to work and back. Go off roading every other weekend to be honest.
I'd suggest you don't use 6th gear and save a whole bunch of money.

How is it in the lower gears? How is it offroad? How much time do you spend in 6th gear? If you're on the highway in 6th gear a majority of the time, a change could be justified. I've got an automatic in mine and if I'm running in hills I typically just kick it out of O/D as it will find itself bogged down and hunting for a gear somewhere in between. My solution is an LS and a 6 speed auto transmission, but for now I just kick it down to 3rd.
jordy is offline  
The Following User Says Thank You to jordy For This Useful Post:
MrCuevas08 (02-22-2019)
Old 02-22-2019, 11:54 AM
  #8  
JK Newbie
Thread Starter
 
Join Date: Feb 2019
Location: Apple Valley
Posts: 3
Thanked 0 Times in 0 Posts
Default

Thank all of you, I really appreciate it.

BORABORA, when I come to a complete stop, my gears feel really rushed, it doesn't pick up speed until I get to 3rd gear. The first three gears feel like I'm not getting any where honestly.

JORDY, Im constantly on the highway, because its my commuter car. I get on the highway every day to get to work. My main speed here is always 60-65 mph. Off-road is perfect, when I'm in 4L, I put it in 3rd and it drives smooth and gets me places. Its only on roads when i come to a complete stop at a light or etc. 3 cars can pass me before i come to the appropriate speed. I don't think I can take my O/D, because I have a manual trans? Because on my wife 07 jk, she has the O/D button is above the shifter on her automatic trans.

ICRASHBIKES, exactly in low gears it feels like I barely move and already I need to change gear. My mpg is like 12 right now on roads and like 15 mpg on highway lol.

Last edited by MrCuevas08; 02-22-2019 at 11:56 AM. Reason: finish
MrCuevas08 is offline  
Old 02-22-2019, 01:12 PM
  #9  
JK Jedi Master
 
Join Date: Jan 2008
Location: Texas
Posts: 10,856
Thanks: 0
Thanked 35 Times in 35 Posts
Default

There is nothing forcing you to actually use first gear. Starting in second for vehicles with a super-low 'granny' first is not all that uncommon, try it and see what you think.

Everything you have posted points to numerically high gearing (my guess is 5.38's from the rpm's you posted), so if you want to run at lower rpm's, you need to either increase tire size or pay for lower numeric gears. Prices can vary wildly for area to area, but $1500ish is fairly common, with a few $999 deals, and a few areas of the country where $3000+ is the norm. While you are calling around for quotes, be sure to ask about the warranty on both gears and labor.

Would you happen to have a programmer/tuner? (perhaps the previous owner included it with the sale?) When new gears and taller tires are installed, the computer needs to be updated so the speedo is accurate. If it's off, your mileage is also off...

Last edited by nthinuf; 02-22-2019 at 06:44 PM.
nthinuf is offline  
The Following User Says Thank You to nthinuf For This Useful Post:
MrCuevas08 (02-24-2019)
Old 02-22-2019, 05:56 PM
  #10  
JK Enthusiast
 
Ajkaz's Avatar
 
Join Date: Apr 2014
Location: Anaheim, ca
Posts: 487
Thanks: 0
Thanked 1 Time in 1 Post
Default

When I had similar gearing and tire size I regularly started in 2nd, shifted to 4th then 6th on the highway.
Ajkaz is offline  
The Following User Says Thank You to Ajkaz For This Useful Post:
MrCuevas08 (02-24-2019)

Quick Reply: 3000 RPMs at 60 mph. Need Help.


Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: