front differential noise?

[OswaldtheBold]

2013 Outback, 57,000 miles. Rumbling noise/feel from front end in tight low speed turns (parking lots). Does it turning both right or left. Only does it when applying throttle. Doesn't do it when sitting still and turning wheel (apparently not the power steering pump or rack). No indication of anything rubbing anywhere. CV boots look good.

Any thoughts?

[turboguzzi]

95% Viscous coupling inside the gearbox gone.... regretfully not a super cheap fix.

Had to change it in my girlfriend's forester, means gearbox out and changing the component.

[idosubaru]

6 hours ago, OswaldtheBold said:

2013 Outback, 57,000 miles. Rumbling noise/feel from front end in tight low speed turns (parking lots). Does it turning both right or left. Only does it when applying throttle. Doesn't do it when sitting still and turning wheel (apparently not the power steering pump or rack). No indication of anything rubbing anywhere. CV boots look good.

Any thoughts?

 Sounds like it’s binding.  

Do all of your tires match in size?

Need to determine if it’s binding, does it also feel like it’s slowing down/braking when it’s doing this?  

Drive in a large paved lot where you and turn the steering wheel all the left or right. Just keep driving in a circle - does the car feel like it’s slowing down and taking more gas rather than coasting through the turn like it should?

Is this a manual transmission, then it’s probably binding and you need a new viscous coupler.  

[OswaldtheBold]

3 hours ago, idosubaru said:

 Sounds like it’s binding.  

Do all of your tires match in size?

Need to determine if it’s binding, does it also feel like it’s slowing down/braking when it’s doing this?  

Drive in a large paved lot where you and turn the steering wheel all the left or right. Just keep driving in a circle - does the car feel like it’s slowing down and taking more gas rather than coasting through the turn like it should?

Is this a manual transmission, then it’s probably binding and you need a new viscous coupler.  

Not a manual, it is a CVT. Does the CVT use the same viscous coupler?

[OswaldtheBold]

5 hours ago, turboguzzi said:

95% Viscous coupling inside the gearbox gone.... regretfully not a super cheap fix.

Had to change it in my girlfriend's forester, means gearbox out and changing the component.

Is there a viscous coupling in the front differential, controlling torque split between right and left axles? Or, is it controlling torque split between front and rear?

I have a CVT. Do you think this might be related, and covered under their extended transmission warranty?

[idosubaru]

1 hour ago, OswaldtheBold said:

Is there a viscous coupling in the front differential, controlling torque split between right and left axles? Or, is it controlling torque split between front and rear?

I have a CVT. Do you think this might be related, and covered under their extended transmission warranty?

Just front to rear.  CVT has a different mechanism than Manual  

You ignored my questions and diagnosis. 

If you think it’s the diff: check fluid level   Then drain the fluid and check fluid for swirls or particulate or chunks. 

Subaru diffs don’t typically make noise only at full lock or tight turns.  That’s low miles and new so this is all surprising and diagnosis and data is better than guessing , but front diff is probably barking up the wrong tree and wasting your time unless additional symptoms exist we don’t know about. 

[idosubaru]

It’s probably a front axle inner joint. They usually last the life of the car so this is odd and should be diagnosed but that’s the closest symptom match by far.  

Id also wonder about wheel bearing or driveshaft. Again - unlikely so symptoms and diagnosis need clarity. 

[idosubaru]

Are the axles original or have they ever been rebooted or replaced? 

[OswaldtheBold]

23 minutes ago, idosubaru said:

Just front to rear.  CVT has a different mechanism than Manual  

You ignored my questions and diagnosis. 

If you think it’s the diff: check fluid level   Then drain the fluid and check fluid for swirls or particulate or chunks. 

Subaru diffs don’t typically make noise only at full lock or tight turns.  That’s low miles and new so this is all surprising and diagnosis and data is better than guessing , but front diff is probably barking up the wrong tree and wasting your time unless additional symptoms exist we don’t know about. 

Thanks. I did not think there was a viscous coupling in the front, controlling side to side torque, but there were two responses suggesting viscous coupling, so I was just brainstorming possible causes.

I did not mean to ignore your questions. Yes, tires are all the same size, same age, same wear.

I have not had a chance to try your suggested diagnosis checks yet.

The rumbling noise first became noticeable this week, but earlier I thought I had heard some tire chirp making a turn into a parking lot at about 20 mph and accelerating out of the turn, and wondered what was causing it.

There was another suggestion of inner CV joint. Boots appear to be intact. Do you think this may be the cause?

 

[OswaldtheBold]

32 minutes ago, idosubaru said:

Are the axles original or have they ever been rebooted or replaced? 

As far as I know, they are original. I bought the car used two years ago. It was a trade-in for a new one and had only been serviced at the dealer, so I have all the service records. No indication of any previous problem with CV joints or axles.

My experience with wheel bearings is they usually only make noise on the outside of turns, and I have never had a car that had both front wheel bearings go out at the same time. This new noise appears to be turning in both directions, so bearings seem an unlikely cause.

[idosubaru]

1. Torque bind - most likely

Parking lot test I mentioned earlier will make it obvious to anyone who’s worked on Subaru’s with torque bind before.  Do it and describe the symptoms as best as possible with a keyboard.

Yours has VTD and I’m not sure of the failure modes they have or what would need to be replaced if it’s binding.  It’s in the rear extension housing and about $600 labor to get at it plus parts to repair.  

inner axle joint is a remote possibility, broken boots aren’t the only failure mode for axle.  At this age and mileage all of these are unlikely, I was just listing a few additional outlier options. 

Edited October 18, 2019 by idosubaru

[1 Lucky Texan]

ist the car new to you? if not, any repairs or wrecks before this began?

[OswaldtheBold]

9 hours ago, 1 Lucky Texan said:

ist the car new to you? if not, any repairs or wrecks before this began?

I bought it used. I am the second owner. It was always serviced at the Subaru dealer since new, and I have all the service records. No indication of any repairs or wrecks.

[OswaldtheBold]

On 10/18/2019 at 5:56 PM, idosubaru said:

1. Torque bind - most likely

Parking lot test I mentioned earlier will make it obvious to anyone who’s worked on Subaru’s with torque bind before.  Do it and describe the symptoms as best as possible with a keyboard.

Yours has VTD and I’m not sure of the failure modes they have or what would need to be replaced if it’s binding.  It’s in the rear extension housing and about $600 labor to get at it plus parts to repair.  

inner axle joint is a remote possibility, broken boots aren’t the only failure mode for axle.  At this age and mileage all of these are unlikely, I was just listing a few additional outlier options. 

OK just got back from the parking lot.

Slow speed tight turns (steering wheel full lock, but not held against the stop) There is a regular periodic chirp from the outside front wheel, and a slight jerk of the steering wheel (not me!) corresponding to each chirp. The chirp period seems to vary accordingly with speed changes, but I really did not have a very broad range of speed to play with. It happens in both right and left turns, and the noise definitely comes only from the outside wheel (I had both front windows open and could tell the difference in which side it came from). The fact that it happened turning both ways, and the noise was from the outside wheel, would seem to rule out wheel bearings as a cause (unless both were bad, which is hard to imagine).

Very difficult to tell if the car was slowing down in the turns (requiring more gas). If I let off the gas, the car slowed down, but I did not have to increase throttle to maintain speed. I did try driving straight ahead to get up a bit of momentum, shifted to neutral and turned. No apparent difference. The chirp was still there as the car rolled through the turn, and slowed down (but not drastically so).

Odd thing about the noise:  If I had not been driving a tight turn in a parking lot, I could as easily have described it as a metal-on-metal chirp as a tire chirp. It did not sound the same as the tire chirp I had heard other times. But, the parking lot had recently been resurfaced, so that could have been the interaction if the tires with different pavement surfaces.

Also, did not notice the rumble noise as much, but that could be because I did not accelerate out of the turns much (tight parking lot), and I was focused on maintaining speed (and the chirp). So. I did not give it too much throttle.

 

Still think it is torque bind?

[idosubaru]

Torque bind. 

Something in the rear extension housing is hosed. 

Id probably source a used one or blown trans and pilfer the entire rear extension housing to swap out.  

I’m not familiar with the VTD failure modes as they’re not common. As such I would be really hesitant to trust a dealer or shop on diagnosis and repair unless they’re good and trust worthy. 

Edited October 20, 2019 by idosubaru

[OswaldtheBold]

14 hours ago, idosubaru said:

Torque bind. 

Something in the rear extension housing is hosed. 

Id probably source a used one or blown trans and pilfer the entire rear extension housing to swap out.  

I’m not familiar with the VTD failure modes as they’re not common. As such I would be really hesitant to trust a dealer or shop on diagnosis and repair unless they’re good and trust worthy. 

Bummer. I wonder if I can convince them to cover it under the extended warranty for the transmission.

[idosubaru]

2 hours ago, OswaldtheBold said:

Bummer. I wonder if I can convince them to cover it under the extended warranty for the transmission.

Yes, ask.  They may need to diagnosis it first to determine warranty. Worth a shot and getting some eyes on it for a second opinion would be nice, maybe it’s something else.  I’m really hesitant to say torque bind over the internet on such a newer low miles VTD... I have so many stories where someone misses information or uses poor word choices or doesn’t see something that seems really obvious nor they’re running on confirmation bias and just looking for what Uncle Johnny told them...and they’re wrong all the time. I typically just ignore what people tell me and start from the beginning.  Anyway - over the internet, new car, rare issue...in still hesitant  

I don’t think that extended warranty is for the rear transfer assembly or the front diff.  Maybe I’m wrong.  Maybe you’ll get lucky or they’ll offer assistance towards repair (that’s my guess at what will happen).   

but it’s old (by new car customer and dealer standards) and out of warranty. No business routinely gives away free money for old out of warranty product. 

If you’re handy at all this could probably be fixed for free and “add a nice feature” to the vehicle. Install a switch on the rear solenoid to control 4WD and just turn it on and off.  Turn it off for FWD and on for 4WD off-road or in snow. I’ve done it on the MPT model trans and I think it should also be the same on the VTDs. 

Edited October 21, 2019 by idosubaru

[OswaldtheBold]

48 minutes ago, idosubaru said:

Yes, ask.  They may need to diagnosis it first to determine warranty. Worth a shot and getting some eyes on it for a second opinion would be nice, maybe it’s something else.  I’m really hesitant to say torque bind over the internet on such a newer low miles VTD... I have so many stories where someone misses information or uses poor word choices or doesn’t see something that seems really obvious nor they’re running on confirmation bias and just looking for what Uncle Johnny told them...and they’re wrong all the time. I typically just ignore what people tell me and start from the beginning.  Anyway - over the internet, new car, rare issue...in still hesitant  

I don’t think that extended warranty is for the rear transfer assembly or the front diff.  Maybe I’m wrong.  Maybe you’ll get lucky or they’ll offer assistance towards repair (that’s my guess at what will happen).   

but it’s old (by new car customer and dealer standards) and out of warranty. No business routinely gives away free money for old out of warranty product. 

If you’re handy at all this could probably be fixed for free and “add a nice feature” to the vehicle. Install a switch on the rear solenoid to control 4WD and just turn it on and off.  Turn it off for FWD and on for 4WD off-road or in snow. I’ve done it on the MPT model trans and I think it should also be the same on the VTDs. 

Thanks. How much damage am I doing by continuing to drive it while trying to get it fixed?

[idosubaru]

2 hours ago, OswaldtheBold said:

Thanks. How much damage am I doing by continuing to drive it while trying to get it fixed?

you may have an outlier issue so generalities are hard to assign.  

Remember Subaru predominantly has used MPT for 4WD over the decades which had higher (but not common) rates of issues. and gradually they’ve shifted to VTDs.  I’m not sure of all the VTD failure modes, they don’t really fail (I’m not counting ones I’ve repaired because they’re damaged by other trans/front diff failures).

I’m basing this off of MPTs which are similar enough that you can swap them - remove MPT and install VTD, trans form factor is the same, etc. so they’re diffent, but this isn’t grasping for straws either. 

In general they’re stout and I wouldn’t be concerned about a couple weeks, a few hundred miles, no big deal.  Im not sure beyond that but getting into many months and thousands will start to get risky. 

Ive seen one or two sheared shafts/drums internally on MPT style...almost certainly from being driven too long with binding.  But get a used one for cheap and labor is free since it needs fixed anyway. So it was a stranding event but not catastrophic and causing more damage. But I don’t know where that VTD weak spot is. 

If it’s completely locked in 4WD you can remove the rear driveshaft and it’ll be FWD and you can drive it indefinitely.  I know people who have done that on purpose for projects and it’s been done lots of times in situations just like yours or for towing on a dolly. 

 

Edited October 21, 2019 by idosubaru

[OswaldtheBold]

The Subaru dealer's opinion: "confirmed customer concern, transfer clutch is not releasing properly, causing a tight binding and rumble noise on sharp turn. Removed transfer clutch and plates looked discolored like they were getting hot."

They replaced the transfer clutch plates and piston, retainer spring, seals, snap rings, shims, oil seal, and changed the CVT fluid.

"Test drove, noise and feel felt better but still a little present, transfer clutch needs to finish breaking in."

It was all covered under the CVT warranty. They said drive it for a few weeks, and if the problem comes back, they will replace the entire CVT with a new one, under warranty.