Chattering Noise when Accelerating Manual Transmission

[hjdca]

I have confirmed the same on mine. It's always in the 3-3.5K range, and simply putting my foot on the clutch pedal stops it, and lifting off the pedal it comes right back.

I initially posted otherwise, thinking it wasn't the pedal, but further experimenting has confirmed it. Now what that actually means to fix it I have no idea.

But I have zero thoughts that's it the CAM or anything, it's just something vibrating/resonating in that particular RPM range.

If it is not the pedal itself vibrating for some reason..., it sounds like the throw out bearing is bad... or what they call the clutch release bearing on the Jeeps.... but, I would bet on pedal slop first...

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[be77solo]

If it is not the pedal itself vibrating for some reason..., it sounds like the throw out bearing is bad... or what they call the clutch release bearing on the Jeeps.... but, I would bet on pedal slop first...

Yeah, it's not even really required to put any pressure on the pedal, even just putting my foot beside the pedal stops it. So seems its something in the pedal or what it's connected to somewhere in that area.

 

[onewhippedpuppy]

I played with this a little bit under the dash, the rod end that connects to the clutch slave cylinder has a small amount of play where it connects to the pedal. It’s a pain to reach but I could slide it back and forth where it connects and make a metallic clicking noise. It would also make sense why pedal pressure makes the noise stop, because pushing the pedal takes out the play. I’d like to remove the lower dash to mess with this a little more, and maybe try adding a thin nylon washer. Has anyone else noticed this?

 

[JTDay]

17k into my 2022 and I've never heard the noise. Not sure what/if anything changed or if I'm just the anomaly.

One thing I have noticed is that if I try to shift like I'm driving a sports car, I've heard quite a terrible, very loud, grinding noise. But obviously the solution to that is don't slam the transmission/clutch into gear like it's a sports car.

 

[hjdca]

17k into my 2022 and I've never heard the noise. Not sure what/if anything changed or if I'm just the anomaly.

One thing I have noticed is that if I try to shift like I'm driving a sports car, I've heard quite a terrible, very loud, grinding noise. But obviously the solution to that is don't slam the transmission/clutch into gear like it's a sports car.

I agree the synchros in the tranny are not good enough to speed shift it like you can a Tremec.

 

[ShadowsPapa]

So only thing with slightly depressing the clutch pedal... The master cylinder has a bleed hole that is open when the clutch pedal is not depressed. It only takes maybe 5mm of pedal travel to close the bleed hole and to start slightly compressing the hydraulic fluid. It is possibly in the pedal as you stated, but by depressing the pedal slightly it may also be compressing the fluid and causing the hydraulic pipe or hose to move enough to not rattle... just a thought.

Can't see that happening with the miniscule pressure you'd put on it - it would likely be in the single digits unless you pressed beyond just the weight of your foot.
If that tiny bit moves anything, you've got serious trouble when you actually press to release.

it sounds like the throw out bearing is bad... or what they call the clutch release bearing on the Jeeps.... but, I would bet on pedal slop first...

Not sure where the "throw out" term ever came from - they have always been release bearings in the parts books I've dealt with. Maybe that came from the tractor arena where you had hand clutches that actually went over-center and threw the clutch out of engagement and held it there until you pulled the lever back again.

I'd expect release bearing sounds to be a bearing sound, not a rattle sound. It would squeal or scrape as it spun.

I agree the synchros in the tranny are not good enough to speed shift it like you can a Tremec.

Better clarify that because Tremec is a group that sells transmissions and they've produced quite a variety, some good, some not so great, some originally designed by Borg Warner.
The T5 is Tremec - and unless it's a World Class version, I'd not think of mashing on it.

 

[hjdca]

Can't see that happening with the miniscule pressure you'd put on it - it would likely be in the single digits unless you pressed beyond just the weight of your foot.
If that tiny bit moves anything, you've got serious trouble when you actually press to release.



Not sure where the "throw out" term ever came from - they have always been release bearings in the parts books I've dealt with. Maybe that came from the tractor arena where you had hand clutches that actually went over-center and threw the clutch out of engagement and held it there until you pulled the lever back again.

I'd expect release bearing sounds to be a bearing sound, not a rattle sound. It would squeal or scrape as it spun.



Better clarify that because Tremec is a group that sells transmissions and they've produced quite a variety, some good, some not so great, some originally designed by Borg Warner.
The T5 is Tremec - and unless it's a World Class version, I'd not think of mashing on it.

I agree on both points. Lol, I have personally killed three T5s in mustangs. 3rd gear speed shifting all 3 times.... I was thinking of the T56, TKO, TKX, and TR-6060 when I wrote that quote. I actually forgot that they made that weak T5 in the 80s and 90s mustangs.

 

[OHJeeper]

I was thinking of the T56, TKO, TKX, and TR-6060 when I wrote that quote.

Sooooo.... you and @ShadowsPapa seem to have some good Tremec knowledge. Question (sorry to hijack the thread) - do you guys know if a TR6060 would fit in a JT in place of the Asin? I know input/output splines may be different, different bell housing, etc but was curious if the unit itself could fit.

 

[hjdca]

Sooooo.... you and @ShadowsPapa seem to have some good Tremec knowledge. Question (sorry to hijack the thread) - do you guys know if a TR6060 would fit in a JT in place of the Asin? I know input/output splines may be different, different bell housing, etc but was curious if the unit itself could fit.

I do not know, but, with the stock motor, I think the manual transmission is fine. I have been happy with the tranny and clutch so far, and I am at 52K miles with lots of 4wheeling and off road.

Now, since there is a 6 speed Tremec with the Challenger SRT, and now a manual in the Hellcat in 2023, I guess it is not out of the realm of possibility that you could swap both the motor and manual tranny into a manual Gladiator. That would be cool to see on you tube. lol.

 

[OHJeeper]

Now, since there is a 6 speed Tremec with the Challenger SRT, and now a manual in the Hellcat in 2023, I guess it is not out of the realm of possibility that you could swap both the motor and manual tranny into a manual Gladiator. That would be cool to see on you tube. lol.

That is sort of my future "vision" (when I have the funds). All the AMW builds are auto-trans and I want to keep my 6MT but I know it won't handle the input torque. I was thinking a 6060 but wasn't even sure how big it was in comparison. I'd even settle for a 5 speed Tremec if it would fit.

Dreams...

 

[IanNubbit]

So couple things to add from me.

1.) I haven't heard my sound for months now. I did remove the clutch return spring on the pedal, Put foam padding on the top and bottom , never heard it again. Im not saying that was the issue, because seems weird that a spring that is applying pressure constantly would be able to rattle lightly, but harmonics are a fun side of physics so, might be worth looking into for y'all since the sound always went away for me barely touching the pedal, but not actually touching the master cylinder rod, oh, that was also not fully clipped in for me, I think I already mentioned that though. Any way, might be worth a check for y'all

2.) The whole Dealer story with the cams, I think his issues caused the rattle, not was the rattle, if y'all catch my drift. Also the cams snap from over torque, not under, seen more then a handful of tech think the torque wrench is not needed on 3.6's, they learn very quick. Also, the cam was worn, and they didn't replace it, or get Chrysler to pay for the LOF?? Yeah, go ahead and make another or lower your review and never go back. That's just assinine.

 

[BuyHold]

Reading through all of the recent updates makes me feel much more reassured that the chattering I also felt is nothing serious. Annoying, yes, serious, likely no if this is it. I haven't experienced the chattering since reading the updates but I am certainly going to be trying to touch the clutch pedal next time i get the chattering and see if it stops.

One thing I found interesting. When driving, if i just push very lightly on the clutch I get a touch of vibrational feedback. Now, I never rest my foot on the clutch as habit but after reading this I wanted to test it and yeah, sort of vibration... strange. I don't recall ever feeling anything like that before on a clutch though, to be honest, i never have tried this with any of my other clutch vehicles.

Could there be some sort of clutch vibration unique to JL clutch that potentially transmits through the hydraulics? Just not sure why that feeling would be there. Not sure why the pedal would vibrate. @onewhippedpuppy might have it right that it is just play in the rod-end slave cylinder.

 

[onewhippedpuppy]

I have also noticed the same vibration when lightly pushing on the clutch pedal. I can’t recall feeling that on any previous manual transmission vehicles, and I’ve owned many.

 

[JTDay]

I'll chime in as another data point here. Also vibes on light clutch pedal press. I assume it's normal. Never had a twin disc clutch before.

 

[Tali Hunter]

Hi All,

The noise occurs when accelerating in the 3k-3.5k RPM range after the transmission is warmed up. I need to drive 5-10 miles, letting the engine warm up isn't enough to replicate the issue.

Here is a video of me recreating the issue: https://photos.app.goo.gl/umvvwU7BFWdwWPDU7

The noise goes away if you lightly press in the clutch (not enough to slip the clutch, but more than if just the pedal was vibrating).

I have been plagued with this issue since the truck had about 2,000 miles on it. Everything has been replaced from the clutch pedal to the entire transmission assembly. The only repairs that have made the noise disappear temporarily was when the clutch, clutch release bearing, and the slave cylinder were all replaced together. That repair has been made twice (the second time the flywheel was also replaced in hopes replacing it all together would keep it from coming back) and it only lasts for about 200 miles.

I have tried higher octane gas with no luck either.

I found this post which matches my noise exactly.


The service manager is stumped at this point, and the corporate mechanic didn't have any luck in diagnosing the issue either. Any thoughts or ideas would be appreciated.

Thank you in advance!

Same issue fellow Jeeper. Same response from two dealers. Jeep care got involved. Of course, they didn’t care. Long story short, they’re incompetent and show no initiative when trying to diagnose a vehicle. Like I said to two other post. My thoughts are for all if us with this issue and all other Jeep people to demand, protest or whatever it takes and make sure Chrysler and their engineers rectify this problem. It’s not that hard. How to do this? Idk. We just need to keep calling, complaint or whatever to Chrysler and maybe get some lawyers involved. I’m personally here soon going to have a professional driver, a jeep certified master tech, and a mechanical engineer check this out. So far I’ve had two dealerships and four different technicians tell me my shifting noise is normal! Yet, they failed to explain why it’s physically or logically doing so. One idiot tech said “there may be slack in the pinion gear.” Hahaha I laughed so hard. I said well if that was the case, my rear end would be toast by now.

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