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Rear Axle System Off - I am at my limits

15K views 26 replies 11 participants last post by  Wireboltman 
#1 ·
Hello,

I will keep this brief, my car is shuddering when toe tapping the acceleration of the car, it feels like driving over the bumps on the side of the road to keep drivers awake. Or very much like when you start a manual in a lower gear and car shake violently. I have many trips back to the dealer with trans noise, seat defects, camera issues.

I can not get my repairs done as they are missing my IPC (Instrument Panel Cluster), the part I have been waiting for since June/July. I am not able to get the part until October or worse. I am not making any more payments towards a car that is giving this much trouble the first year. I planned on keeping this car for ten years.

During a recent trip I was going 60 miles per hour and barley touching the gas and the shudder came about and my car flashed a message that the rear-axle is off. I think I am having issues with the rear differential with the shudders, hard shifts knocks and the delay to move the car forward.

Wanted to post this hear to keep you all informed.

Jonny
 
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#3 ·
Thanks for the msg, I am still working with Cadillac and I love the car but they can not even get me replacement parts, I waited for new Recaro seats because the are falling apart and the repair was just denied because the new part number has the same issue!

I make this payment every month and I have been waiting for multiple parts since March!
 
#5 ·
OK I have an update that might be of interest to all ATS-V and CTS-V users

It seems like there is a handful of V Series cars that are having issues with the torque converter. As my car was coming back from the dealer yet again with no fixes I got PM on this forum from @Goldminer.

He suggested I take a look at the torque converter and when I called my dealer back, they found the same issue themselves by mere hours. If they did not @Goldminer would have saved me some huge headaches.

Unfortunately, I do not have my replacement dashboard\IPC or my seats yet. The new recaro seats with the new part number are still effected so the repair was denied.

If you guys are having any issues with your transmission where it jerks or rumbles when you tow tap in traffic To check drive 20-40 minutes @ 30-60MPH with much toe tapping to accelerate and de-accelerate at light thrust you will start to feel a rumble like driving over the strips to keep people awake if they fall asleep driving. Usually when noticed it goes away after a few seconds.

Get you torque converters checked my peeps!

ShoutOut to user "Goldminer"
 
#7 ·
Hello bhartlage,

Try googling "2015 Corvette torque issues" and that should help out.

The best way to explain it shudders under light acceleration.

Hope this helps, I get my car back today and not sure if this will also help the jerk shifts (i think that is a different issue with the PAS - performance algorithm shifting)

Good luck and I will report my finding backs here.
 
#8 ·
OK so I picked up the car after 2 weeks with the repair on the torque converter.

The car felt a little quicker to react and move when initially pressing the pedal now and was happy at first but with-in 30 minutes the car starting to make the shudder vibrating noise and unfortunately it starting making a new noise that I have never heard before and it is so loud.

What went from a slight hesitation in the pedal which made a vibration, I now have it feel a bit quicker but these is a mechanical noise sort of like a pan with screws , as if the pan was vibrating. Like a shaky metal grate.

The issue in this thread is most repeatable by staying between 30-60 MPH (Sport or Touring mode) with slight acceleration to keep up with traffic. I would say between 1000-1,200 RPM's it gets this shake still but now followed with a shaky metal grate noise.

Went from happy to sad, again.

BTW Cadillac is refusing the replace my Recaro seats as they new part number has the same issue. I was at the dealer and all ATS and CTS V's have the same crunching sound and I am sure they will bubble.
 
#14 ·
OK so I picked up the car after 2 weeks with the repair on the torque converter...
To my knowledge, there is no way for a dealership to "repair" a torque converter, as they are typically sealed units. They should have replaced the converter, if the converter was the root problem. The symptoms you're describing would indicate that the lock-up clutches in the converter are chattering, rather than fully engaging. On the mechanical side, this could be caused by a problem with the converter itself, or it could be due to insufficient hydraulic pressure coming from the pump in the transmission...but I would think if that was the case, you'd also be experiencing odd/weird shifting behavior. Then on the electronic side, there are also possible TCM issues. So, while it will take some careful diagnostic work to discover the exact cause, they really should have gotten the correct answer by now...unless they don't have anyone capable of that level of diagnostics. In that case, they'll just throw parts at it until they get lucky, and you'll unfortunately be expected to persevere until they do.

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Separate post due to lack of "edit" function. I jumped on the torque converter rather than the differential because the OP didn't say the problem only occurs when going around a corner. If it also occurs when going in a straight line, it's hard for me to believe the problem is in the differential...
 
#9 ·
I just had my car to the dealership this morning. I drove my car for 30 minutes before I arrived to make sure the transmission was warmed up enough to replicate the shuddering. After a few minutes of repeated ight acceleration from 57mph to 65mph with the transmission tech driving we were able to reproduce the shuddering. He also noticed it happens around 50mph. The tech stated that he thinks there is definitely something wrong and it could be the torque converter. He would like to replace the entire transmission, but this decision is ultimately up to GM. I'm dropping my car off on Tuesday for them to work on and am not sure at this point if they will replace the torque converter or entire transmission. I'll keep you posted.
 
#13 ·
Found this

Subject:* Rear Axle Off Message In The DIC

Models:* 2016 Cadillac ATS-V

#PIP5336A: Rear Axle Off Message In The DIC -

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern

Some customers may comment on a Rear Axle Off message Displayed in the DIC. Customer may also indicate the message goes away as soon as it comes on.* The concern may happen while driving highway speeds in a straight line.*The rear differential module will reset causing a 135 ms lapse of limited slip operation typically no DTC’s are set and it is very hard to duplicate.

Recommendation/Instructions

Verify the exact message that the customer reported. A Service Rear Axle message would have DTCs stored and should be addressed and repaired. A Rear Axle Off message with a C0414 Sym54 should also be diagnosed and repaired. If there are no Rear Differential Control Module dtc's then reprogram the Rear Differential Control Module and perform module set up as outlined in Service Information.
 
#27 ·
I had this message come on while on the way back from CA in May.
I Googled it and no big deal as far as running the car.
I had the the TSB number handy when I went to my home dealership and the rear end was reprogrammed.

It only happened once on the way back in exactly the way described above and not since.
 
#18 ·
Short lived victory for me:sob: After just getting my car back from the dealer this morning...it's back at the dealership and I'm back in the loaner XT5 again. I drove the car for around an hour with the new torque converter and it drove really well. When I stopped at a drive through and put my car in park I noticed the car started substantially vibrating for a few seconds at a time while idling. This vibration happened in park, neutral, and drive with my foot on the brake so basically at idle in any gear. I had the dealership tech look at it again and he agreed this wasn't normal behavior and doesn't seem to have any idea what the problem could be at this point. Good tmes.
 
#19 ·
I get my car back tomorrow. The vibration during idle was caused by a bad O2 sensor on the driver side. It may have gone bad during the torque converter replacement or just failed coincidentally afterwards. Either way I'm glad it was a minor issue and an easy fix. My dealership has been great to work with and provided outstanding customer service.
 
#20 ·
i have the same issue and i should of read some posts before posting my self but whatever my headline calls it what it is. and shows how to replicate.

My cars been in the dealership for two weeks. first converter was damaged. second was installed and finished today but apparently now my trans wont shift. Wonder what is happening. there. Never had a shifting issue before.

So I'm sure ill get another call tomorrow with the Sa saying something about how i cant have my car again. maybe the tech broke something or didn't connect something. i dont know I'm not there. they changed out my torque converter as well as said they would flush and change the trans filter.

i miss my car. Allthough not too upset I'm in a brand new ct5 or whatever its called. but its not my V.

----------

Seems a bunch of people are having the same problem yet there is no bulletin about it yet. or anything. So basically if you don't know how to make it appear for the tech Your SOL.
 
#22 ·
I'd like to put forward the hypothesis that this is not an issue with the torque converter mechanicals, but rather a software issue, possibly on the engine side rather than the transmission side. I'm hoping someone will eventually get enough information out of a dealer to prove me right or wrong. I'm reluctant to bring my car in, because of a nagging suspicion that the dealer won't know what the root cause is and will instead start doing experimental surgery.

My hypothesis is based on the observations that 1) the shudder doesn't seem to be simply a rotational vibration in the transmission (which you would expect to be continuous and present both on- and off-throttle), 2) the shudder comes on and off like a light switch, 3) it doesn't last long, 4) there is no RPM fluctuation during the shudder. Sometimes it lasts for only a tenth of a second; it's never more than a second. It's analogous to what would happen if a knock sensor detected knock and yanked spark advance, or cylinder deactivation kicked in and out. My undoubtably accurate rear end tells me that the acceleration is lower while the shudder is happening, as if the engine is producing less power. I am puzzled as to how the torque converter could cause this sort of behavior, especially when it's locked up as I think it is under the scenarios people are describing (granted, things may be more complicated than they seem).

If the dealer replaced the torque converter and the problem went away, then I wonder if the powertrain control module was reprogrammed. Could it be that it's actually the reprogramming that fixed the issue instead of the torque converter replacement?

Thanks to anyone who has gone through this who might be able to shed more light.
 
#23 ·
I just looked at my repair paperwork from the dealership and it makes no mention of reprogramming any modules, but that doesn't mean they didn't as part of the normal repair procedure. My torque converter was replaced and I haven't had any shuddering since. My dealership techs seemed pretty confident that the shuddering was a tell tale sign of a bad torque converter. I'm still getting a very hard shift from park to drive when the car isn't fully warmed up. Otherwise the car has been driving very well.
 
#24 ·
Good to know - thanks bhartlage.

Apparently the magic search term is "chuggle", although "shudder" also works.

I found the following page that is directly relevant to the 8L90:

http://gm.oemdtc.com/3397/torque-converter-clutch-tcc-shudder-2015-cadillac-chevrolet-gmc

It reads, in part:


These vehicles may have a condition in which transmission calibration allows a higher than target energy input to the torque converter clutch (TCC) under certain conditions.

This may lead to faster than expected torque converter clutch material wear, and a shudder feeling when the TCC is applied.

Parts Information

No parts are required for this repair.


It goes on to describe how to reprogram the TCM to resolve the problem.

I found the following posted on another forum. It's regarding the 5L50-E in the STS, but it seems very relevant. Does anyone who had this fixed at the dealer know if they tried commanding the TCC off with a scan tool and found that the problem went away? (to be clear, that's just a diagnostic test, not a solution to the problem)


Doc ID# 2009091 2007 Cadillac STS

Subject: 5L40-E/5L50-E Transmission Torque Converter Clutch (TCC) Surge, Shutter, Exhaust Moan, Chuggle at Low Speed and Light Load (Reprogram TCM) #06-07-30-030A- (09/05/2007)

Models: 2004-2007 Cadillac CTS 2005-2007 SRX, STS with V6 Engine (VIN Codes 7, N, T – RPOs LY7, LA3, LP1) 2004-2006 SRX 2005-2006 Cadillac STS with V8 Engine (VIN Code A – RPO LH2)

Condition: Some customers man comment on a shudder, surge or chuggle on light throttle under light load just after torque converter clutch (TCC) engagement. Others may comment on an engine exhaust moan in the 1200 RPM range between 65-73 km/h (40-45 mph). This occurs with the transmission at normal operating temperature and commanding the TCC off with the scan tool will eliminate the concern.

Correction: New transmission calibrations have been released to correct this condition in both V6 and V8 applications. Reprogram the TCM using SPS. This new service calibration is available on TIS2WEB. After reprogramming the TCM, if the condition persists and mileage is greater than 40,234 km (25,000 mi), replace the torque converter, flush the transmission oil cooler, and replace the transmission fluid. If the condition persists, contact the Technical Assistance Center (TAC)


Searching on this website for "chuggle" turns up 187 hits. I have not gone through them yet.
 
#25 ·
@1wayjohnny - I feel your pain. I bought an ATS 48 hours ago and within 24 hours of purchase, I felt this same shudder. Took it to Cadillac in Grapevine, TX and they said it was a Torque Converter. Their going to replace it and also some seals, trans filter and fluid. Someone made mention of when the torque converter fails, it sometimes can produce metal shavings that can make their way into your transmission. Maybe that's why their replacing the fluid and filters as standard protocol . Either way, I'll keep everyone posted. Super frustrated because I bought this car on Wednesday and immediately had to go to the shop.
 
#26 ·
Just to follow up on my experience... After two test drives with the tech at the dealership logging data on his laptop, we confirmed that the "stumble" or "chuggle" was from the ECCC slipping more than it should in a narrowly defined but common driving condition. You should know that the ECCC torque converter clutch intentionally slips a small amount when it is fully engaged in low torque conditions such as highway cruise. This is a clever way to absorb driveline vibrations. The amount of slippage is quite small, on the order of 30-50 RPM (difference between input and output shaft speed). The amount of slippage is governed by hydraulic pressure to an actuator under computer control. The material used in the clutch is reinforced with carbon fiber and will happily absorb this slippage for the design lifetime of the car. We were seeing slip rise to 100 RPM or so when we tipped into the accelerator from highway cruise, and it was under this condition that you could feel a mild and short-lived vibration (half a second or so). Presumably the torque increase from the pedal tip-in induced stick-slip friction in the clutch rather than a smooth slippage and that's where the vibration came from. On other GM cars with this transmission, this has apparently been fixed by adjusting the ECCC calibration, presumably to affect the torque converter apply pressure. However, the tech said there was no new calibration for the ATS-V, and he had heard that it was possible that there was a problem with the torque converter friction material delaminating on some cars, which would affect its ability to provide controlled slippage. I left the car with him for a couple weeks. He replaced the torque converter under warranty *and* reflashed the transmission control module, so perhaps there was a recalibration after all. I'll never know for sure. But I can report that the issue has gone away entirely.
 
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