My Jeep has Emphysema - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > TJ Wrangler Technical Forum > My Jeep has Emphysema

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineJeep Wrangler Bushwacker Flat Fender Flare Sale at BaselinGear Installs at CCOR Special

Reply
Unread 09-28-2012, 01:52 PM   #1
R-Sticker
Registered User
2006 LJ Wrangler 
 
Join Date: Apr 2012
Location: Andover, Taxachusetts
Posts: 29
My Jeep has Emphysema

My engine is laggin' badly. It's a 42RLE with 33" tires (285/75r16) and 4.88 R&P. I think it is dropping into OD at about 50 MPH. Once there, the RPMs sit at about 1200 on flat roads. To get a downshift, I have to put the pedal on the floor.

I just put in the 4.88s and have not put a new speedo gear in, but that should not effect the transmission. Any ideas?

R-Sticker is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 02:03 PM   #2
Unlimited04
This post/info=my opinion
 
Unlimited04's Avatar
2004 LJ Wrangler 
 
Join Date: Dec 2005
Location: Colorado
Posts: 23,492
Quote:
Originally Posted by R-Sticker View Post
It's a 42RLE
found the problem!



if you're shifting into OD at 50mph, you're doing better than most. Typically the shift into OD w/ 4.88s and 33s is around 38 mph.
Unlimited04 is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 03:16 PM   #3
R-Sticker
Registered User
2006 LJ Wrangler 
 
Join Date: Apr 2012
Location: Andover, Taxachusetts
Posts: 29
Quote:
Originally Posted by Unlimited04 View Post
found the problem!



if you're shifting into OD at 50mph, you're doing better than most. Typically the shift into OD w/ 4.88s and 33s is around 38 mph.
Are you saying that I should have put in 5.13s? I don't know how that would go at 80 mph.
R-Sticker is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 03:21 PM   #4
Unlimited04
This post/info=my opinion
 
Unlimited04's Avatar
2004 LJ Wrangler 
 
Join Date: Dec 2005
Location: Colorado
Posts: 23,492
Quote:
Originally Posted by R-Sticker View Post
Are you saying that I should have put in 5.13s? I don't know how that would go at 80 mph.
No, I'm saying you shouldn't have bought a 42RLE...because your experience is normal for this transmission.
Unlimited04 is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 06:49 PM   #5
rchase559
Registered User
2003 TJ Wrangler 
 
Join Date: Nov 2009
Location: 'Merica
Posts: 2,153
You would are doing approximately 35 MPH at 1200 RPM

At 50 MPH you should be at about 1700 RPM

Get the correct speedometer gear and report back to the class
rchase559 is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 07:00 PM   #6
fromme
Registered User
1994 YJ Wrangler 
 
Join Date: Aug 2004
Location: Suffolk, VA
Posts: 1,168
Quote:
Originally Posted by Unlimited04 View Post
No, I'm saying you shouldn't have bought a 42RLE...because your experience is normal for this transmission.


Sad for me to remember but I sold my first TJ Rubicon because of this transmission. With 5:13s and 35s and trying to lighten it as much as I could, it was still a pig and drove like a pig. I hated it on the road, and I hated it on the rocks. My current TJ is a 6spd and I'm running 4.88s and 33s taching 3000 rpm at 70 and lovin every minute of it.
About the best you can do is get in the habit of reaching down and hitting the O/D cancel button every time you start it up.
__________________
"The Wicked Flee When No Man Pursueth, But The Righteous Are Bold As A Lion."
fromme is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 07:14 PM   #7
R-Sticker
Registered User
2006 LJ Wrangler 
 
Join Date: Apr 2012
Location: Andover, Taxachusetts
Posts: 29
Quote:
Originally Posted by rchase559 View Post
You would are doing approximately 35 MPH at 1200 RPM

At 50 MPH you should be at about 1700 RPM

Get the correct speedometer gear and report back to the class
Yes, Mr. Schoolmaster. I was waiting for someone to point that out. I need a 41-tooth speedo gear. My RPMs might be the same, but my speedometer may be... as you say... 35.

Next question: how difficult is it to swap a 42RLE to a NSG370 (or AX15 or NV3550)... ?
R-Sticker is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 07:17 PM   #8
JBTJ
JEEPer For Life
 
JBTJ's Avatar
2001 TJ Wrangler 
 
Join Date: Mar 2006
Location: Dallas, Texas
Posts: 10,263
Bottom line is the 42rle is a piece of !!!! No matter what you do to it it's still a 42rle. Kind of like the D35, which is better. But still a piece of !!!! Sorry guys.
JBTJ is offline   Reply With Quote Quick reply to this message
Unread 09-28-2012, 07:32 PM   #9
rchase559
Registered User
2003 TJ Wrangler 
 
Join Date: Nov 2009
Location: 'Merica
Posts: 2,153
I'm pretty sure the PCM/TCM takes vehicle speed into account when it determines when to shift.

I think the wiring on yours is a bit different but on my 2003 the wiring for the transmission is heavily integrated into the rest of the wiring harness. There doesn't appear to be any disconnects to easily remove the transmission wiring.
rchase559 is offline   Reply With Quote Quick reply to this message
Unread 09-29-2012, 06:20 AM   #10
4banged
Registered User
2003 TJ Wrangler 
 
Join Date: May 2010
Location: connecticut
Posts: 694
I don't think the speedo change will effect shifting...I know it didn't on my 03 going from stock 28's to 31's. Theres a speed output sensor on the tranny that the tcm/pcm uses in its moronic shift formula. The speedo is only for your gauge from what I've read. You need to start a close relationship with your OD button...hit it any time you get on highway and get it up to 65 before hitting again. Welcome to the 42rle fan club!
My biggest complaint is it doesn't release the torque converter clutch under load in OD like it does in 3rd. I have no idea why it was programmed like this.
4banged is offline   Reply With Quote Quick reply to this message
Unread 09-29-2012, 06:41 AM   #11
R-Sticker
Registered User
2006 LJ Wrangler 
 
Join Date: Apr 2012
Location: Andover, Taxachusetts
Posts: 29
Quote:
Originally Posted by fromme View Post


About the best you can do is get in the habit of reaching down and hitting the O/D cancel button every time you start it up.
Yea, it looks like I'll be switching off the O/D at start-up (and turning it back on when I hit the highway).

I need to save my ducats for a V8....
R-Sticker is offline   Reply With Quote Quick reply to this message
Unread 09-29-2012, 10:11 AM   #12
rchase559
Registered User
2003 TJ Wrangler 
 
Join Date: Nov 2009
Location: 'Merica
Posts: 2,153
Quote:
Originally Posted by 4banged View Post
I don't think the speedo change will effect shifting...I know it didn't on my 03 going from stock 28's to 31's. Theres a speed output sensor on the tranny that the tcm/pcm uses in its moronic shift formula. The speedo is only for your gauge from what I've read. You need to start a close relationship with your OD button...hit it any time you get on highway and get it up to 65 before hitting again. Welcome to the 42rle fan club!
My biggest complaint is it doesn't release the torque converter clutch under load in OD like it does in 3rd. I have no idea why it was programmed like this.
My 42RLE doesn't seem to shift into OD and lock up TC until 45 no matter how far off my speedometer is. In my experience it does have some bearing on the shift points. Even when going from 30's to 33's and then 33's to 35's while still on 3.73s.

Tapping the brakes just enough to turn the lights on will unlock the TC. Yes its annoying but this combined with learning how and when to use the OD off button will make the transmission more usable IMO.
rchase559 is offline   Reply With Quote Quick reply to this message
Unread 09-29-2012, 10:53 AM   #13
77351wcj5
Registered User
2003 TJ Wrangler 
 
Join Date: Feb 2010
Location: Central Louisiana
Posts: 538
Quote:
Originally Posted by R-Sticker View Post
Are you saying that I should have put in 5.13s? I don't know how that would go at 80 mph.
If you look at a gear calculator for the .69 overdrive ratio, you may determine that a 5.13 gear would be too high.

5.38's @ 3,000 rpm would give you 80 mph, 120mph @ 4500 rpm - given you have the horsepower to pull that speed.
77351wcj5 is offline   Reply With Quote Quick reply to this message
Reply

Tags
engine , lag , shift points , speedo gear , transmission

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com 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 e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.