Grinding when down shifting into second gear. - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 03-21-2013, 07:27 PM   #1
Jeeper
 
rwhitmore74's Avatar
 
Join Date: Mar 2012
Posts: 221
Grinding when down shifting into second gear.

When I am slowing down and shift into second gear around 15 mph it grinds with clutch in. If I put it into second at 10 mph or below its fine. Just to be clear this only happens down shifting at 15 mph. Everything else is fine.

rwhitmore74 is offline   Quote Quick Reply
Old 03-21-2013, 07:29 PM   #2
Jeeper

WF Supporting Member
 
jp2611's Avatar
 
Join Date: Aug 2010
Location: Fort Wayne IN
Posts: 5,511
Full console? any BL or SL? How many miles? and which motor?

jp2611 is offline   Quote Quick Reply
Old 03-21-2013, 07:44 PM   #3
Jeeper
 
Patrick H's Avatar
 
Join Date: Nov 2011
Location: Northern NM
Posts: 3,089
Are you matching RPM's? Try double-clutching..
Patrick H is offline   Quote Quick Reply
Old 03-21-2013, 08:15 PM   #4
Jeeper
 
kpla51's Avatar
 
Join Date: Jun 2012
Location: fort sill
Posts: 676
could be the synchronizer my buddy had the same issue shifting into 2nd and 3rd. they syncro is there so there is no need to double clutch. I'm sorry to hear that i know the sound is unpleasant
kpla51 is offline   Quote Quick Reply
Old 03-21-2013, 08:26 PM   #5
Jeeper
 
UFOtestpilot's Avatar
 
Join Date: Nov 2012
Location: Portland, Oregon
Posts: 1,493
As stated if you rev-match by blipping the throttle enough to raise the RPM's to what they're about to be in second gear as you shift you shouldn't have an issue. Usual suspects generally are synchros or selector fork. The fluid usually has excessive brass flakes in it if its synchros. I am also of the belief that double clutching only works on straight cut or non-synchro helical cut gearboxes.
__________________
For some, it is easier to kill the light inside of themselves than it is to fight the darkness all around them.
UFOtestpilot is offline   Quote Quick Reply
Old 03-21-2013, 08:51 PM   #6
Jeeper
 
Patrick H's Avatar
 
Join Date: Nov 2011
Location: Northern NM
Posts: 3,089
Quote:
I am also of the belief that double clutching only works on straight cut or non-synchro helical cut gearboxes.
Double clutching has almost the same effect as RPM matching. When the clutch is engaged briefly as you pass through neutral, it causes everything on the mainshaft assy. to come to the same speed, reducing the RPM differences between the synchro collar and the gear before the dog teeth engage. Is double clutching needed on a synchronized tranny? No, but it helps, especially if the synchros are worn.
Patrick H is offline   Quote Quick Reply
Old 03-21-2013, 10:46 PM   #7
Jeeper
 
rwhitmore74's Avatar
 
Join Date: Mar 2012
Posts: 221
2 bb lift and inline 6 with 130,000 miles.
rwhitmore74 is offline   Quote Quick Reply
Old 03-21-2013, 10:47 PM   #8
Jeeper
 
rwhitmore74's Avatar
 
Join Date: Mar 2012
Posts: 221
What is double clutching?
rwhitmore74 is offline   Quote Quick Reply
Old 03-21-2013, 10:50 PM   #9
Jeeper
 
Patrick H's Avatar
 
Join Date: Nov 2011
Location: Northern NM
Posts: 3,089
Quote:
Originally Posted by rwhitmore74 View Post
What is double clutching?
You quickly let the clutch out and then depress it again as you pass the shifter through the neutral position a while giving the throttle a blip to match the engine RPM to the gear your down shifting to. I got very good at it driving early CJ5's with non-synchroed 1st. gears..
Patrick H is offline   Quote Quick Reply
Old 03-22-2013, 05:05 AM   #10
Jeeper

WF Supporting Member
 
jp2611's Avatar
 
Join Date: Aug 2010
Location: Fort Wayne IN
Posts: 5,511
Quote:
Originally Posted by rwhitmore74 View Post
2 bb lift and inline 6 with 130,000 miles.

The reason I had asked the questions about BL and Sl and console and miles...has to do with my experience after my Jeep was lifted, 2nd gear was more difficult to get into, after both the SL and BL. (2 seperate occasions) about 2 years apart. Also because the mounting bolts for my console are "worn" it rides forward a little which interferes with the shifter.


I had my clutched replaced and it is a little better, (after it started slipping) I usually have the most problems when it is cold.

Even after all that SOMETIMES I still have trouble if I get lazy or am in a hurry with the shifting.

I had almost the exact same miles when I changed my clutch, on my '04 Sport with the 4.0 I6.


IMO the lift interferes with the "lines/ angles" of the shift linkage, and is part of the issue. It also puts the shifter against the console.

IDK if the double clutching will "fix it", but it will slow down your shifting to the point where it might eliminate the problem.

Hope this helps?
jp2611 is offline   Quote Quick Reply
Old 03-22-2013, 05:39 AM   #11
Jeeper
 
jtg51's Avatar
 
Join Date: Mar 2013
Location: federal way, WA
Posts: 30
Mine does same thing. I believe it is the angle that the transmission sits after the lift. I hear a slip yoke eliminator will help this or if a manual shift, slightly bending the shifter to compensate the lift. My lifts instructions actually recommended the latter. Hope this helps
jtg51 is offline   Quote Quick Reply
Old 03-22-2013, 07:43 AM   #12
Jeeper
 
Patrick H's Avatar
 
Join Date: Nov 2011
Location: Northern NM
Posts: 3,089
No, double clutching isn't a fix, and shouldn't be necessary. It can make high speed or high RPM down shifts smoother. Double clutching doesn't "slow down" shifting, either.
Patrick H is offline   Quote Quick Reply
Old 03-22-2013, 10:00 AM   #13
Jeeper
 
Atthehop's Avatar
 
Join Date: Jul 2008
Location: NW, NJ
Posts: 3,699
If you try to downshift to fast you will override the syncros. Jeep transmissions are not like cars, they are more truck like and require slow and easy shifting.
__________________
Retired my 94 YJ 4cyl 5spd @ 200K
Now in a 04 TJ 4cyl 5spd CV @120K+
Both as a commuter vehicle in NW, NJ
April 2012.downsized and now a 99er.
Atthehop is offline   Quote Quick Reply
Old 03-22-2013, 10:06 AM   #14
Jeeper
 
KevinNJ's Avatar
 
Join Date: Jul 2012
Location: Morris County NJ
Posts: 297
I had this grinding as well. While changing out the fluid isn't a guarantee, it solved 99.9% of my grinds (which was doing it close to 100% of the time prior to the fluid change). I went with the synchromesh from the local jeep dealer because I could find royal purple or redline. After I changed it out, still had some grinding for the first couple of hundred miles, but it is tremendously better now.

KevinNJ is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

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

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 Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 09:57 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC