Manual Transmission - Issues shifting into 1st & Reverse (Compilation thread)

[toothirtyj]

- What month/year was your JL manufactured? 07/2021

- If you can confidently say what part number slave cylinder your JL was originally equipped with, what is/was the part number? 04581906AB

- Do you have a new clutch, if so what brand/part #? Yes/ACT JP6-HDSS

- Was your original OEM slave cylinder kept with the new clutch, or replaced with a new OEM slave cylinder during clutch replacement? Original OEM

- Has the clutch hydraulic system been broken open (for bleeding, line/part replacement, leaks, etc)? NO

- If the clutch hydraulic system has been broken open, are you confident it has been properly bled and returned to factory spec? N/A

- Do you currently have any of the previously described shifting issues? YES

- If "YES", to what degree ("noticable", "aggravated", "undriveable") of shifting issues are you experiencing based on what others have described? Noticable

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[LatteSipper]

- What month/year was your JL manufactured? 02/2021

- If you can confidently say what part number slave cylinder your JL was originally equipped with, what is/was the part number? 04581906AB

- Do you have a new clutch, if so what brand/part #? Yes/ACT JP6-HDSS

- Was your original OEM slave cylinder kept with the new clutch, or replaced with a new OEM slave cylinder during clutch replacement? Original OEM

- Has the clutch hydraulic system been broken open (for bleeding, line/part replacement, leaks, etc)? NO

- If the clutch hydraulic system has been broken open, are you confident it has been properly bled and returned to factory spec? N/A

- Do you currently have any of the previously described shifting issues? YES

- If "YES", to what degree ("noticable", "aggravated", "undriveable") of shifting issues are you experiencing based on what others have described? Noticeable

 

[OldGuyNewJeep]

- What month/year was your JL manufactured? 06/2018 (2dr - I mention that because mine will be lighter).

- If you can confidently say what part number slave cylinder your JL was originally equipped with, what is/was the part number? 04581906AB

- Do you have a new clutch, if so what brand/part #? Yes/ACT JP6-HDSS

- Was your original OEM slave cylinder kept with the new clutch, or replaced with a new OEM slave cylinder during clutch replacement? Replaced twice when ACT was installed because installer mis-aligned the fork 2x

- Has the clutch hydraulic system been broken open (for bleeding, line/part replacement, leaks, etc)? Yes

- If the clutch hydraulic system has been broken open, are you confident it has been properly bled and returned to factory spec? Yes

- Do you currently have any of the previously described shifting issues? YES

- If "YES", to what degree ("noticable", "aggravated", "undriveable") of shifting issues are you experiencing based on what others have described? Noticeable, though very rare. I’ve had trouble shifting out of reverse from cold start in parking lots 2x. My wife says she has trouble getting into 1st sometimes, but that doesn’t happen to me. (User error, I think. Ssshhh.) I do notice that shifting is not quite as smooth as it was when clutch was installed. Pedal feels fine. Installed June 2023. About 13k miles on it, now.

 

[CorvZ061]

I haven’t read the the entire thread, I’ve been following it for months and may not remember .

Just curious, since it seems maybe the issue it’s with the clutch disc sticking in the input shaft. Anyone had this issue with the stick clutch? If not has anyone swapped back to a new oem clutch and the problem remained? I currently have 7500 miles on my 4 month old ‘24 and thus far everything has been fine.

 

[OldGuyNewJeep]

I haven’t read the the entire thread, I’ve been following it for months and may not remember .

Just curious, since it seems maybe the issue it’s with the clutch disc sticking in the input shaft. Anyone had this issue with the stick clutch? If not has anyone swapped back to a new oem clutch and the problem remained? I currently have 7500 miles on my 4 month old ‘24 and thus far everything has been fine.

There are a couple reports of this happening with stock clutch.

 

[AVGeek99]

- What month/year was your JL manufactured? 09/2021

- If you can confidently say what part number slave cylinder your JL was originally equipped with, what is/was the part number? No Clue

- Do you have a new clutch, if so what brand/part #? Yes/CF II

- Was your original OEM slave cylinder kept with the new clutch, or replaced with a new OEM slave cylinder during clutch replacement? Replaced with CF slave

- Has the clutch hydraulic system been broken open (for bleeding, line/part replacement, leaks, etc)? Only to replace the slave cylinder when CF clutch was installed

- If the clutch hydraulic system has been broken open, are you confident it has been properly bled and returned to factory spec? Yes, I've never had an issue with pedal feel or clutch engagement

- Do you currently have any of the previously described shifting issues? YES

- If "YES", to what degree ("noticable", "aggravated", "undriveable") of shifting issues are you experiencing based on what others have described? Noticable to borderline aggravated. If I don't pull it out of gear prior to starting, it's hard to get out of gear once started. If stopped without clutch depressed for more than a couple seconds I have to first put it in 4th prior to 1st, but when I do this it slides very easily in to 1st. 3rd and 5th are very notchy. I don't think I could live with it as is if I was in a lot of stop and go traffic.

 

[luishasmail]

Following up here since my last post. I had originally planned to take my Wrangler back to the shop after the second master cylinder replacement. However, the day after I made my original post the problem went away and I could not for the life of me get it to come back. I tried a lot of things but the Jeep pretty much always went in and out of gear without issue. Some of the shifts still felt a little chunky but for the most part the problem seemed to have disappeared.

I ended up deciding not to take the Jeep back to the shop and after a whole week of driving it the problem has not returned. My best guess for what happened is that perhaps after the second master cylinder replacement the system was not completely bled. The pedal certainly felt kind of off after I left the shop and as each day has gone by it's gotten more and more normal. Right now it feels like it did before I had any problems. So.. hurray? Maybe some of the symptoms we're all experiencing can be alleviated by replacing hydraulics.

I will add the information I know about my Jeep here:

What month/year was your JL manufactured (find on driver's door on long silver sticker w/ VIN)?
8/21

If you can confidently say what part number slave cylinder your JL was originally equipped with, what is/was the part number?
Unfortunately the first time I replaced the slave cylinder I promptly threw it away. I have the part number for the original pressure plate though and I imagine it can be used to figure out the part number for the slave cylinder: 68273845AD

Do you have a new clutch, if so what brand/part #?
ACT/JP6-HDSS

Was your original OEM slave cylinder kept with the new clutch, or replaced with a new OEM slave cylinder during clutch replacement?
I did not replace any hydraulics or open the system when I replaced the clutch. Everything was fine for about 20k miles although I did start to feel that getting into 1st was getting harder and sometimes after starting the Jeep getting out of first or reverse was challenging. I started having serious problems after towing a buddy off a trail. After this, everything was eventually replaced: the master cylinder, the slave cylinder, and the hydraulic line.

Has the clutch hydraulic system been broken open (for bleeding, line/part replacement, leaks, etc)?
Yes, several times.

If the clutch hydraulic system has been broken open, are you confident it has been properly bled and returned to factory spec?
Yes and no. It's definitely been bled to different levels of success.

Do you currently have any of the previously described shifting issues?
Yes and no, after the second replacement of the master cylinder I occasionally have a very chunky shift into 3rd but the Jeep always goes into gear at a stop.

If "YES", to what degree ("noticeable", "aggravated", "undriveable") of shifting issues are you experiencing based on what others have described?
Before towing my buddy: very occasionally noticeable
After towing my buddy: undriveable
After replacing the master cylinder a second time: very occasionally noticeable and only really with shifts into 3rd.

 

[cander58]

I haven’t read the the entire thread, I’ve been following it for months and may not remember .

Just curious, since it seems maybe the issue it’s with the clutch disc sticking in the input shaft. Anyone had this issue with the stick clutch? If not has anyone swapped back to a new oem clutch and the problem remained? I currently have 7500 miles on my 4 month old ‘24 and thus far everything has been fine.

Happening with my stock clutch since getting the recall performed

 

[SadRobot]

Ok I'm back with an update with almost 5k miles after re-install of ACT.

Friday night I was picking up a friend at the airport and got stuck in stop and go traffic at the terminal for about 20 minutes. Since then occasionally I've had some resistance with 1st gear. It's not getting locked out like before but sometimes it just doesn't want to go in as smoothly as normal.

I've also developed this odd "ka-chunk" sound when taking off from a stop into 1st. Again not all the time just every once in a while. It sounds and feels if it is coming from the floorboard or pedal. I have not been successful in duplicating it. It just seems to happen randomly.

I'll be hitting the road soon to head to Moab so will report back after that trip to see if things have stayed the same or gotten worse.

 

[JEEP4U]

When you folks are replacing your clutches and masters, I hope you are paying close attention to eliminate heat build up in the hydraulic system.

Utilize your favorite heat wrap, such as DEI or Thermo-Tech on the master to slave hydraulic line. Also, utilize a quality brake fluid such as Pentosin.
Jeep thought is was a great idea to place a catalytic converter right below the brake / clutch systems; without additional protections. I also utilized a Grimm Offroad Compressor bracket to install additional heat shielding.

Helped me...... Still have the latest Centerforce Clutch system in a box. It's been 4 years now on original OEM clutch....No software.

and yes I'm on 40's and 5.38 gears

 

[azwjowner]

When you folks are replacing your clutches and masters, I hope you are paying close attention to eliminate heat build up in the hydraulic system.

Utilize your favorite heat wrap, such as DEI or Thermo-Tech on the master to slave hydraulic line. Also, utilize a quality brake fluid such as Pentosin.
Jeep thought is was a great idea to place a catalytic converter right below the brake / clutch systems; without additional protections. I also utilized a Grimm Offroad Compressor bracket to install additional heat shielding.

Helped me...... Still have the latest Centerforce Clutch system in a box. It's been 4 years now on original OEM clutch....No software.

and yes I'm on 40's and 5.38 gears

Care to share some photos of what you did? I have a stock clutch (2022), no intent to replace it until it wears out, wondering if I should take any similar precautions now. I do notice when my Jeep is thoroughly heat soaked I occasionally get a rattle when passing through 3k RPMs.

 

[gek]

When you folks are replacing your clutches and masters, I hope you are paying close attention to eliminate heat build up in the hydraulic system.

Utilize your favorite heat wrap, such as DEI or Thermo-Tech on the master to slave hydraulic line. Also, utilize a quality brake fluid such as Pentosin.
Jeep thought is was a great idea to place a catalytic converter right below the brake / clutch systems; without additional protections. I also utilized a Grimm Offroad Compressor bracket to install additional heat shielding.

Helped me...... Still have the latest Centerforce Clutch system in a box. It's been 4 years now on original OEM clutch....No software.

and yes I'm on 40's and 5.38 gears

Hmm, I wonder if mine might have something to do with my lack of issues. Not totally covering it up but it is blocking a lot of the space below it.

 

[SadRobot]

I did some reading around and found this old thread which seems to have my new issue.

I found this video of a Miata that best shows the sound since I can't replicate it all the time. Seems like every time I solve one Jeep issue another one comes up.

https://packaged-media.redd.it/3pzk...00&s=6dda0ff8465e55bd9a064ada137a76eb2f566ad9

 

[SadRobot]

Hmm, I wonder if mine might have something to do with my lack of issues. Not totally covering it up but it is blocking a lot of the space below it.

Hmm maybe I should buy some sheeting and put it over the line maybe? Or mount in between... just to see if it does anything.

Today I only had 1 instance where it was a little stubborn to get into 1st. I think the clunk sound I developed is related to the control arms I just greased and not related to the clutch at all. I'm not sure what I did by greasing them and when I try to move the arm around it has no play so not sure what I f'd up.

 

[gek]

Hmm maybe I should buy some sheeting and put it over the line maybe? Or mount in between... just to see if it does anything.

Today I only had 1 instance where it was a little stubborn to get into 1st. I think the clunk sound I developed is related to the control arms I just greased and not related to the clutch at all. I'm not sure what I did by greasing them and when I try to move the arm around it has no play so not sure what I f'd up.

My trackbar used to do that on trails. I could never get anything to move upfront, and torqued everything to spec, but every time I went on trails I would get a "clunk". I used a gopro to help me figure it out and I tightened my upper trackbar and it is finally gone after several attempts at finding it.

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