2005 Subaru Outback Wagon with manual trans drivetrain problem. Crab-walking and slipping

Maintenance/Repairs
1

My 2005 Subaru Outback wagon equipped with manual transmission is exhibiting some difficult to diagnose drivetrain issues that have been getting (slowly and progressively) worse. I’m planning on taking it into the shop next week, but I just thought I’d run my question past the Gurus first.

The car’s mileage is approaching 150K and I’ve had it since about 40K. Over the years I’ve replaced front axle and joint assemblies several times due to cracked boots, so I think the CVs should be fine. The car is due (overdue) to have its shocks and struts replaced as it’s getting a little bouncy and floaty at highway speeds.

Over the past 60K miles or so it’s started going through tires faster than it should (excessive wear and cupping on outside edges) seems to be worse on the left side.

This winter I noticed that the car began lurching, skipping, “crab-walking,” when I crank the steering wheel hard left or right and turn the car (getting into and out of parking spaces etc.) Mainly it does this on slick surfaces, but it will occasionally do it on hard/dry surfaces as well. My local mechanic changed the fluid in the viscous couplings (clutch-packs), but this hasn’t helped the situation.

The car also feels like the clutch for the transmission may be finally wearing out because it’s started “slipping” a bit in the last few weeks. Oddly, the clutch on this car has never felt strong in the time I’ve owned the car and occasionally would slip (once every couple of months, say) even when I first bought the car at 40K. Anyway, the other day it slipped/lurched about 10-12 times in one short trip of about 12 miles (roundtrip)–but then (just as strange) seemed fine again the next day on an equal length trip.

So, I guess my question is, do you think this clutch slipping and “settling-in” sensation I’m experiencing is in fact the clutch or perhaps something else in the drive train that is making the AWD couplings slip?

The car also has a tendency to pull a little to the left (from the rear of the car) at highway speeds when going over uneven or bumpy road surfaces. I was thinking that all AWD cars might do this with bad shocks, but it seems like there’s something bigger going on here.

So, that’s it. Lots of expensive problems, where to start? Looking forward to the communities thoughts/insights. I noticed someone else had posted about a car with similar symptoms that were cured by repairing a rear axle drifting problem.

2

The low speed lurching & crab-walking is the result of a worn-out center viscous coupler.
This is usually the result of one or more of the following mistakes:

Using tires that are not precisely-matched as to the amount of tread wear, size, or brand
Failure to rotate the tires on a consistent basis (every 5k or 7.5k miles)
Running the car for an extended period of time on a donut spare

It is also possible that the viscous coupler has simply worn out from normal use, but they do tend to last for a very long time if you use matched tires and if you rotate them consistently. After you replace the center viscous coupler, make sure that you don’t engage in any of the scenarios listed above.

3

You have two separate problems, the slipping clutch and suspension components either worn out or damaged. Since it’s been a gradual regression in handling, I feel confident in suggesting wear as the cause.

“Suspension components worn” could be as simple as all four of the shocks/struts having become very soft and one of them then freezing up. I’ve had a shock become frozen, and it can cause an imbalance that can manifest itself as this sideways feeling.

You could also have a strut tower rotted out. I’ve seen that too.

Let us know what the shop finds.

4

^
Actually, I see this as three separate problems:

A worn-out clutch
Badly-worn suspension components
A damaged or worn-out center viscous coupler

To use an old cowboy expression, I think that this horse has been ridden hard and put away wet.