2011 Subaru Impreza Outback Sport - Torque Binding on Turn

[natdog1984]

My daughters first car is a used 2011 Impreza, it drives great 90% of the time, sounds awesome, etc.

The only issue is that when turning @ slow speed (less than 15 mph) it shudders, either direction.
During my servicing (I do some repairs myself), it presented code P0741 and the traction light came on.
I cleared it but noted the code.

The previous owner apparently had it serviced with a Transmission & Diff fluid change, 1 time.
I have seen recommendations to do it multiple times.
Dealer is recommending a rebuild and replacement of Transfer Clutch Assembly ($1800) + tax...

Is it worth doing multiple flushes of the fluids first?

 

[Ecmbuster]

Either direction meaning forward and reverse or on turns?
What engine, what transmission?
Are there faults recorded with the ABS?
Are all 4 wheel speed sensors operating? There is no binding with the brakes?
Are all 4 wheels identical in circumference?
Simple OBD II scan tools will never be able to access a Subaru network.
Subaru uses the SSM (Subaru Select Monitor) protocol and also comprises a CAN network.
Check the fluid levels first and ensure the correct fluid is being used.
Test first before diving into multiple repairs especially "rebuild and replacement of Transfer Clutch Assembly ($1800) + tax" when the fault code points toward a "torque converter" fault.

 

[natdog1984]

Either direction meaning forward and reverse or on turns?
What engine, what transmission?
Are there faults recorded with the ABS?
Are all 4 wheel speed sensors operating? There is no binding with the brakes?
Are all 4 wheels identical in circumference?
Simple OBD II scan tools will never be able to access a Subaru network.
Subaru uses the SSM (Subaru Select Monitor) protocol and also comprises a CAN network.
Check the fluid levels first and ensure the correct fluid is being used.
Test first before diving into multiple repairs especially "rebuild and replacement of Transfer Clutch Assembly ($1800) + tax" when the fault code points toward a "torque converter" fault.

Either left or right hand turns.
It has the 2.5L H4 EJ253 with 4 Speed Automatic (Not Sure the Exact Model)
No faults found other than P0741 by myself or the Subaru Dealer
- The ABS light has come on with the Traction Control Light once.
- I am gonna compare the tires a bit better, but I believe they are matched, they also rotated and inspected them at dealer.
- I am concerned as the previous fluid change was done at small mechanic shop in middle of no where, may not have done the exact correct fluid.

I already replaced brakes and rotors, as they were worn and I wanted to be sure they were not the culprit. They appear good, and no caliper abnormalities, etc. No squeek, just the shuttter, and only during acceleration not braking.

So during acceleration from 1 - 15mph while also turning, the issue occurs. I have not experienced it in reverse, and it seems worse the harder you turn.

I am leaning toward a fluid change/flush maybe multiple times as there are youtube videos of people with similar binding when turning resolved by flushing diff and tran fluid. Just wondering if this was something that was a common thing.

Really looking for assurance. Thanks for the reply.

 

[Ecmbuster]

The 4 speed automatic should be the 4EAT model.
P0741 is a generic code but points to the transmission torque converter circuit.
The ABS system may complain but would still check all four ABS sensors to ensure the speeds match straight ahead.
Right turns will have the left wheels turning faster, left turns will have the right wheels turning faster.
That model should also have a steering angle sensor. Straight ahead and driving, the sensor should read 0 degrees and increase negative or positive on steering wheel turns.
Make sure no one added a Subaru center differential lock switch. Applying 12V to the differential lock assembly will not allow the front and rear differentials to "slip" and feel that binding anomaly. Use this link as an example:

4wd switch for 4EAT trans

I had been contemplating performing this mod for some time now to my auto '00 Impreza OBS. For any of you Subaru 4EAT owners, I'm sure you agree the...

mnsubaru.com

Make sure the correct oils are replaced, make sure no other "mechanical differential locks" are installed.
This may help as well:

TRANSMISSION SECTION - Google Drive

drive.google.com

 

[natdog1984]

First of all, thanks so much the documentation, that is great stuff. Is there a complete archive somewhere of Subaru documentation that is available or is this just a private share? Just wanting to know if there is a link I should have for any future issues. This is our 3rd Subaru. Have not had to do much yet on the others, as they are a 2014, and a 2022.

So got the Impreza back from the dealer, I declined the rebuild for now. They did reset the TCM Learning Process.
It is shifting a bit harder at the moment, but they said that is normal for resetting the TCM.

My Plan :
- Phase A: (Using Idemitsu ATF Type HP, and Lucas Oil 70w-90)
1. Drain ATF Fluid, Remove Pan, Replace ATF Filters (Both)
2. Install New ATF Fluid
3. Drain Front & Rear Differential
4. Install New Differential Fluid

- Phase B:
1. Drive it first day easy (cater to the car)
2. Drive it second day a bit harder, fast accel, tighter turns, etc
3. Drive it third day normal

- Phase C: (Using Subaru ATF Fluid, and RedLine 70w-90)
1. Drain ATF Fluid
2. Install New ATF Fluid
3. Drain Front & Rear Differential
4. Install New Differential Fluid

Please let me know if something in this plan is dumb. I prefer to know I am being dumb, before proceeding, plus I ordered new jack stands, so it will be a couple of days before I can get to it.

 

[Ecmbuster]

Never intermix oils in the transmission or differential.
Use the OEM standard or equivalent.
1) The preferred test is to measure "Torque Converter Slip"
2) Inspect the TCM (Transmission Control Module), did someone add or wire a "Subaru center differential lock switch"
3) Measure the ABS as mentioned
4) With 1,2 and 3 eliminated, follow your phases.

 

[natdog1984]

So got FreeSSM, OBDLink, and took a drive around.

The shutter occurs at the low speed turning still of course.

A. Measured front wheel speed, vs dash speed, vs GPS and all seem to be within 1/2 kph of each other at any given time.

B. Can sometimes replicate the P0741 Code issue. It occurs sometimes when hard accelerating + turning.

C. I can see the load transfers, etc.

I don't have ABS Sensors listed in FreeSSM. Do they show up in BtSSM, does anyone know?

 

[Ecmbuster]

BtSSM works similar to FreSSM

ActiveOBD - Apps on Google Play

Multi function display app for Subaru vehicle MY 2012+ (not official)

play.google.com

ActiveOBD is also similar and if that model connects via CAN diagnostics, will show AWD % between the from and rear axles.

One example using the application is posted for the "Variable Valve Timing error"
Link : https://www.thesubaruforums.com/threads/low-gas-mileage.13354/
Last post.

Again, the correct procedure is to look for any unwanted updates that may have been attached to the TCM (Transmission Control Module) wiring harness under the dash.
With a scan tool that reads ABS, the steering angle sensor can be measured.
Degrees to the right or left will increase / decrease and rest at close to 0 Deg straight ahead.
Torque converter slippage is measured at slow speeds and locks (closed) at high road speeds.
ABS sensors track equally straight ahead.
Right turns will track the left speed sensors faster.
Left turns will track the right speed sensors faster.
Binding axles will also create that same issue.

The transmission active torque split:

Subaru Symmetrical All Wheel Drive Explained | Sport Subaru

www.sportsubaru.com

If the transmission active torque split is equal front to back and the torque converter is operating correctly, then you will know there is damage to the hydaraulic transfer clutch.

Subaru all wheel drive explained

All all wheel drive Impreza, Legacy, Outback, Forester, Tribeca, and XV vehicles

www.awdwiki.com

That is why I eliminate all other possibilities and diagnose the offending component.

 

[Sylvain]

Bonjour j ai le même probleme avec mon impreza 2011, avez vous résolu le problème? Et si oui comment, svp. Merci!

 

[natdog1984]

So long time, solved some of the issues.
The torque binding is no longer occuring, and the car is driving great except when going up a hill, when the throttles up I get the p0741 and the ABS and TC lights and it disables cruise. Once this happens there is a pecking (which sounds like it is in rear).

Turning the car off and back on removes all the issues and it will drive great again sometimes for days.

I have checked the voltages, looked for switches, etc. Has the right fluids, in the right amounts.

The issue occurs regardless of the car being in FWD mode.

The dealer said they believed it was a clutch pack but it just really stumps me why a clutch would manifest only is a specific situation and the pecking sound. I have never experienced anything quite like it.

 

[GwenJP1959]

My daughters first car is a used 2011 Impreza, it drives great 90% of the time, sounds awesome, etc.

The only issue is that when turning @ slow speed (less than 15 mph) it shudders, either direction.
During my servicing (I do some repairs myself), it presented code P0741 and the traction light came on.
I cleared it but noted the code.

The previous owner apparently had it serviced with a Transmission & Diff fluid change, 1 time.
I have seen recommendations to do it multiple times.
Dealer is recommending a rebuild and replacement of Transfer Clutch Assembly ($1800) + tax...

Is it worth doing multiple flushes of the fluids first?

I replaced the clutch on my twenty eleven five speed subaru impreza last year, Now my car is doing the same thing , and I am told it is the viscuss coupler. Are you sure you have the right diagnosis??