[raz-0]

I tried to have this flash done at the local dealer but they claim it doesn't apply to my 2017 1.4L 6spd. Does anyone know if 08-027-21 is for the automatic only? The wording is unclear - it should not matter as the rear wet clutch is the same in both.

the tsb is for renegades with awd and an automatic transmission. It’sa flash for the drive train control module for an at+awd.

 

[FiatPower]

the tsb is for renegades with awd and an automatic transmission. It’sa flash for the drive train control module for an at+awd.

Shame - the manuals have the same issue with the rear diff, I wish they'd bring out an update for the those too.

 

[briki-boi]

So "JeepCares"



We left ours with our local dealer for an extra day to give them more time to experience the problem so they might have some idea how to repair it, but they continue to say they can't duplicate the problem. They're not driving it much, is all I can say.

I assume "JeepCares" means you represent Jeep, and your responses seem to indicate this is a known issue. So is a TSB in the works? What is the expected timeline for a fix?

My ‘17 Rene latitude 4x4 also experiences this growling/rumble strip sensation. Happens to me like clockwork at 37mph and cuts off when hopping into the next gear. Tends to happen on the deceleration as well.

Just wanted to add a couple specifics for things I’ve noticed with this issue. In addition to the 4wd lock “fix”, turning off traction control (while not advised, unless doing donuts 🍩 ❄) also “fixes” it. it also only happens if the ambient temp is over 40-45 ish degrees. Thankfully it’s getting colder where I stay, so I’m enjoying a really pain free ride for the most part.
TLDR; if it snows where you stay, drive it below freezing and see if it doesn’t just “go away” until it’s warm enough out. Also it just cuts through snow like butter on a hot knife. (Shoutout to classic Jeep moves!)

Anywhoozle y’all, I took a video of it on a 50 degree day because I was bringing it to the dealership on a day I knew would be below freezing… wouldn’t you know it they couldn’t replicate the issue at all and once again, the Rene passes the vibe check with flying colors.

Today it’s about 60 degrees in Michigan and it’s growling like a rabid dog. Lol FML. Help.

 

[FiatPower]

I'm going to continue playing with rear diff fluid to see what difference that makes. I first replaced it with synthetic 75W-90 GL5 WITH the limited slip additive (because that's easier to find). Trying to decide what to try next:

1. Increase the amount of LS additive
2. Try oil without LS additive
3. Try heavier weight oil

So far I think this is a mechanical resonance that occurs when the front dog clutch is opened (around 37mph), as that is when there is there is a significant speed differential between the plates of the wet clutch. If the speed increases above ~50mph then the resonance seems to stop or drastically decrease.

Curious that turning off traction control stops it - I had not tried that. Still, it's probably just a programming change that prevents opening the front clutch at those speeds.

I want the front clutch to open for improved mileage, but I'm concerned that a mechanical resonance that strong may be creating parasitic friction/drag anyway - which might negate the benefits of disconnecting the driveshaft.

 

[FiatPower]

I tried it tonight and can confirm that turning off traction control stops the noise, which I find interesting. Apparently with traction control off they run the drive shaft instead of shutting it off - so you have more traction but less traction control!

 

[FiatPower]

I'm going to leave these links here:

Fiat 500X All Wheel Drive System Explored

The Fiat 500X uses an advanced all-wheel drive system that guarantees excellent traction in the worst slippery conditions. Here is how the system works.

www.fiat500usa.com

GKN Automotive | One AWD platform, two distinct driving experiences

GKN Automotive is the first tier one supplier to design, develop, manufacture and integrate a complete all-wheel drive system into a customer’s vehicle. The system that underpins FCA’s Jeep Renegade and Fiat 500X delivers specific brand characteristics based on GKN Automotive's tuning capabilities.

www.gknautomotive.com

Note that when the drive shaft is engaged it is the rear wet clutch that spins up the driveshaft first, then once it's up to speed the front dog clutch engages. I'm pondering what this means in terms of the noise. That happens when the driveshaft is stationary, but not sure where in the process.

My real concern is that it's a bearing problem in the rear diff. When the driveshaft is disengaged the entire hypoid drive gear is stationary, so there must be a bearing between that ring gear and the differential unit. That bearing would only operate when the driveshaft is disengaged, which is also when it's noisy.

Also, I've been trying to see if there is a difference in fuel mileage between running with traction control on or off, but I have not seen it yet. Maybe too many variables? Anyway, it should be better with it on and the driveshaft stationary.

Someday I will get one of these rear units out of the junkyard.

 

[raz-0]

So far I think this is a mechanical resonance that occurs when the front dog clutch is opened (around 37mph), as that is when there is there is a significant speed differential between the plates of the wet clutch. If the speed increases above ~50mph then the resonance seems to stop or drastically decrease.

Curious that turning off traction control stops it - I had not tried that. Still, it's probably just a programming change that prevents opening the front clutch at those speeds.

I want the front clutch to open for improved mileage, but I'm concerned that a mechanical resonance that strong may be creating parasitic friction/drag anyway - which might negate the benefits of disconnecting the driveshaft.

AWD is disabled above 50mph, which is why it goes away at 50mph.
The noise is dependent on the traction control programming, which is why it goes away when it is below 40F (It's really 37F I believe, which seems to be the industry standard bridges may be icy warning temp). Once it is cold enough it switches to a different TC algorithm when in auto mode for the 4wd. It should also greatly diminish in wet weather. In my experience the noise happens, but in a much narrower range of circumstances when it is very wet. (My daily commute from 2015 to 2019 had about 12 miles in the noise sweet spot, so I got to analyze it a lot in spring, summer, and fall).

As for it being a bearing problem, I don't think it is defective or worn bearings, and I don't think it wears out the bearings. Primarily because we haven't seen lots of complaints of failing RDUs. If your bearings are making noise, they tend to not last that long. I got a bum RDU with my 2015. It was only about 3000 miles before the 37mph grinding noise was WAY louder and happened from 10mph to 70mph.

 

[FiatPower]

AWD is disabled above 50mph, which is why it goes away at 50mph.
The noise is dependent on the traction control programming, which is why it goes away when it is below 40F (It's really 37F I believe, which seems to be the industry standard bridges may be icy warning temp). Once it is cold enough it switches to a different TC algorithm when in auto mode for the 4wd. It should also greatly diminish in wet weather. In my experience the noise happens, but in a much narrower range of circumstances when it is very wet. (My daily commute from 2015 to 2019 had about 12 miles in the noise sweet spot, so I got to analyze it a lot in spring, summer, and fall).

As for it being a bearing problem, I don't think it is defective or worn bearings, and I don't think it wears out the bearings. Primarily because we haven't seen lots of complaints of failing RDUs. If your bearings are making noise, they tend to not last that long. I got a bum RDU with my 2015. It was only about 3000 miles before the 37mph grinding noise was WAY louder and happened from 10mph to 70mph.

The bearing fear was just a background concern, it really seems to be a mechanical resonance.

Mine does not really "go away" at higher speeds, rather it fades in amplitude. By 60 it's really hard to hear, but still there. So as speed increases you can hear it turn on at around 37 (as the clutches open), and then it's loud until maybe 50 or so, and decreases from there. At any time during this you can turn off the traction control, and there will be a bit of a clunk and the noise will stop instantly.

As long as the driveshaft is engaged then everything is turning at about the same speed and there is nothing to resonate.

 

[Tito Sam]

Faint rumble strips is a good description. The wife and I called it a low frequency hum. Nonetheless it took them forever along with multiple trips in for the tech to replicate the problem even though we felt it immediately. After a back and forth with the engineers they replaced the rear diff. Diff motor goes with the whole unit as we. Noise went away entirely. That was late 2015. With an off the boat date of 4/15 (forgot actual build date) we're on our 3rd diff and possibly a transfer case with an entirely different sound.. something much more horrific!
4WD is unavailable and now functions as a 2wd vehicle. Severe grinding sound when slowing or sometimes rough roads. This noise happened back in November over a year after replacing the diff the last time. So they did it again even though it wasn't the same noise or ultimate outcome as the first incident. Now it's March 2017 and it's back again with that same horrific noise and no 4wd. This time.. dude says it's the transfercase. My theory is that something there could be blowing the diff and that it will need both as there was a shaft broken off in the diff the last time. There is a star case with this reoccurring driveline issue however the 64,000 dollar question is at 40k is it still under the initial claim or is it under out extended warranty which in that case they only cover days of rental.. it's been there almost a week now


Sent from my iPhone using Tapatalk

Faint rumble strips is a good description. The wife and I called it a low frequency hum. Nonetheless it took them forever along with multiple trips in for the tech to replicate the problem even though we felt it immediately. After a back and forth with the engineers they replaced the rear diff. Diff motor goes with the whole unit as we. Noise went away entirely. That was late 2015. With an off the boat date of 4/15 (forgot actual build date) we're on our 3rd diff and possibly a transfer case with an entirely different sound.. something much more horrific!
4WD is unavailable and now functions as a 2wd vehicle. Severe grinding sound when slowing or sometimes rough roads. This noise happened back in November over a year after replacing the diff the last time. So they did it again even though it wasn't the same noise or ultimate outcome as the first incident. Now it's March 2017 and it's back again with that same horrific noise and no 4wd. This time.. dude says it's the transfercase. My theory is that something there could be blowing the diff and that it will need both as there was a shaft broken off in the diff the last time. There is a star case with this reoccurring driveline issue however the 64,000 dollar question is at 40k is it still under the initial claim or is it under out extended warranty which in that case they only cover days of rental.. it's been there almost a week now


Sent from my iPhone using Tapatalk

Faint rumble strips is a good description. The wife and I called it a low frequency hum. Nonetheless it took them forever along with multiple trips in for the tech to replicate the problem even though we felt it immediately. After a back and forth with the engineers they replaced the rear diff. Diff motor goes with the whole unit as we. Noise went away entirely. That was late 2015. With an off the boat date of 4/15 (forgot actual build date) we're on our 3rd diff and possibly a transfer case with an entirely different sound.. something much more horrific!
4WD is unavailable and now functions as a 2wd vehicle. Severe grinding sound when slowing or sometimes rough roads. This noise happened back in November over a year after replacing the diff the last time. So they did it again even though it wasn't the same noise or ultimate outcome as the first incident. Now it's March 2017 and it's back again with that same horrific noise and no 4wd. This time.. dude says it's the transfercase. My theory is that something there could be blowing the diff and that it will need both as there was a shaft broken off in the diff the last time. There is a star case with this reoccurring driveline issue however the 64,000 dollar question is at 40k is it still under the initial claim or is it under out extended warranty which in that case they only cover days of rental.. it's been there almost a week now


Sent from my iPhone using Tapatalk

Greetings Sports Fans....I had a non MOPAR Mechanic check out my motor mounts top and the lower right strut and it turns out they were both bad and upon replacing engine mount and strut mount I am happy to say no rumble .... I noticed that they updated the mounts both upper and lower the thing interesting my Trail-hawk had the new strut and the Latitude had the old one, go figure all four replaced IF you have a rumble check your mounts instead of the flash-fix it will be easier also google the mounts Summit has the mounts by Anchor and MOPAR website also has them non rebuilds and I saved some coin on the mounts and getting them installed Good luck everyone PLEASE CHANGE YOUR MOUNTS THEY ARE BAD

 

[raz-0]

Greetings Sports Fans....I had a non MOPAR Mechanic check out my motor mounts top and the lower right strut and it turns out they were both bad and upon replacing engine mount and strut mount I am happy to say no rumble .... I noticed that they updated the mounts both upper and lower the thing interesting my Trail-hawk had the new strut and the Latitude had the old one, go figure all four replaced IF you have a rumble check your mounts instead of the flash-fix it will be easier also google the mounts Summit has the mounts by Anchor and MOPAR website also has them non rebuilds and I saved some coin on the mounts and getting them installed Good luck everyone PLEASE CHANGE YOUR MOUNTS THEY ARE BAD

The first generation motor mounts are trash. They are also not the source of the noise being discussed.

 

[17GrayRenegadeSport]

My 2017 Sport has the rumble. When I put it in manual mode, the rumble goes away. Also when I turn off the traction control, the rumble goes away. My question is, will it hurt to turn off the traction control every time I get into my Renegade? Most of my driving is in town driving...but at speeds around the 35 mph mark...which causes the rumble.

 

[raz-0]

My 2017 Sport has the rumble. When I put it in manual mode, the rumble goes away. Also when I turn off the traction control, the rumble goes away. My question is, will it hurt to turn off the traction control every time I get into my Renegade? Most of my driving is in town driving...but at speeds around the 35 mph mark...which causes the rumble.

I did it for years without issue. It shouldn’t harm anything.
But if you have the 2.4 you should get the firmware update. It doesn’t eliminate it entirely, but it gets pretty close.

 

[17GrayRenegadeSport]

I do have the 2.4...going to call my dealer tomorrow and see about getting the firmware update. What exactly does the firmware update do...improve?

 

[raz-0]

I do have the 2.4...going to call my dealer tomorrow and see about getting the firmware update. What exactly does the firmware update do...improve?

Nobody says officially, but it likely is a matter of how the wet clutch in the rear drive unit is managed.

 

[FiatPower]

The noise happens when the driveshaft is disengaged at both ends. At low speed the driveshaft is always driven from the front - probably with the traction control shut off too. I'd bet the the firmware update just keeps it spinning or changes the speed where it disengages.

 

[17GrayRenegadeSport]

I contacted my local Jeep dealership and set up an appointment to have the technicians look at my Renegade. Hopefully they'll be able to update the firmware and help correct the problem. They're going to look at it on Friday.

 

[17GrayRenegadeSport]

I contacted my local Jeep dealership and set up an appointment to have the technicians look at my Renegade. Hopefully they'll be able to update the firmware and help correct the problem. They're going to look at it on Friday.

I took my Renegade in to Friendship Jeep here in Bristol, TN today and they checked into the annoying vibration. They updated the software and also determined that the rear differential was not in the best shape so they're going to replace the rear diff...and the best thing is that all of this is covered under their LIFETIME powertrain warranty. That covers the engine, transmission, etc. They had to order the parts so it's going to be 2-3 weeks. On the way home the vibration was noticeably less than it was, so the software update helped a lot. The service department at Friendship did a great job for me today. I highly recommend Friendship Jeep!

 

[17GrayRenegadeSport]

I took my Renegade in to Friendship Jeep here in Bristol, TN today and they checked into the annoying vibration. They updated the software and also determined that the rear differential was not in the best shape so they're going to replace the rear diff...and the best thing is that all of this is covered under their LIFETIME powertrain warranty. That covers the engine, transmission, etc. They had to order the parts so it's going to be 2-3 weeks. On the way home the vibration was noticeably less than it was, so the software update helped a lot. The service department at Friendship did a great job for me today. I highly recommend Friendship Jeep!

Well...I got a call from the Friendship Jeep dealership today and I had to bring my Renegade in so a Jeep technician could inspect the vehicle to make sure that the issue with the differential would not cause further damage to the drivetrain. They told me that he would be at the dealership within 24 to 48 hours and if the vehicle wasn't there to be inspected they could void the warranty. Hopefully they'll just say I can drive and it won't cause further damage...but with the way my day went today, I don't totally expect that to happen. I did get a loaner vehicle, Chrysler 200C, but it's not my Renegade.

 

[17GrayRenegadeSport]

Well...I got a call from the Friendship Jeep dealership today and I had to bring my Renegade in so a Jeep technician could inspect the vehicle to make sure that the issue with the differential would not cause further damage to the drivetrain. They told me that he would be at the dealership within 24 to 48 hours and if the vehicle wasn't there to be inspected they could void the warranty. Hopefully they'll just say I can drive and it won't cause further damage...but with the way my day went today, I don't totally expect that to happen. I did get a loaner vehicle, Chrysler 200C, but it's not my Renegade.

Well...The technician finally showed up late in the afternoon on Thursday. Today I got a call from the Jeep dealership and the warranty company has approved of the replacement of the rear differential and anything else that might need to be replaced. The parts should be here sometime early next week. Hopefully that will fix my Renegade!

 

[heuristic.developments]

Resolved:
Replaced stock 600 amp battery with best 650 amp (had to step outside warranty & pay $300+ install) after year of problems with countless solutions, including FCA replacing PTU.
Evidently the original battery was insufficient to disengage the running gear - explaining why shifting to manual or locking 4WD quieted the "Renegade Rumble".
Note that the replacement was not made capriciously, but after failure to start.
2021 Jeep Renegade Limited, all options including tow (but not cold weather heater)

PS - suddenly the stop/start began ... stopping and starting. Every service interval the dealer charged the battery, the S/S started working only to stop the next day. Go figure.
FCA could have saved beaucoup bux by providing the premium BBH6A001AA in the first place.