Hard left turn circle - odd rolling behavior

[milty60]

09 Suby Forester AWD manual 240K 

I checked the front left and right inner and outer CVJ boots - no cuts - turning a tight right or left circle - no clicking - check movement of each front axle by hand - no movement. Tie rods , ball joint , wheel bearing by moving tire in out up down left right while jacked off ground  - shows no play. 

If I turn the wheel full left and roll through the circle - its hard to describe - but it feels like - when a bubble is in the tire and at each rotation you feel that bump consistently - does not happen on extreme right turn - I assume its the outer CVJ on the left axle - any thoughts? any other way to diagnose? 

Thanks, 

Milty 

 

 

[idosubaru]

It does it while coasting in neutral?

Rotate tires and see if it "moves". 

You could also swap axles from side to side and see if the symptoms cease, change, or move....but that's a lot of needless work. 

[milty60]

Haven't tried it coasting - only in first tight left circle. I'll test over the weekend. Rotate tires good idea. Swap axles - sounds like a lot of work. 

Thanks, 

Milty 

[idosubaru]

Yeah only a certain person would want to swap axles.   I would try to get somewhere where you can coast into the same situation that causes the noise and see if it does it coasting in neutral to see if it's only related to the angle or if it needs to be under load to do it.  

Does it sound like it's a "corner" sound - like at the knuckle/wheel bearing/axle/bushing or does it sound a little bit centered like maybe it's the inner CV?  The inner axle joint often causes a lower frequency duller sounding "knock" than the outer which tends to "click click click" faster.  But I guess either way if you can narrow down whether it's the left or right side it doesn't much matter - either way you're probably replacing the axle. 

Have the axles ever been replaced? If they're aftermarket axles then have a party if they lasted a couple years, that's pretty good for those trash heaps. 

Install a new Subaru unit or reboot a used Subaru axle.  aftermarkets have an incredibly high failure rate. 

[Rampage]

Do you feel the "bump" in the steering wheel?

I found this on our 95 RHD Legacy. Check the transmission and motor mounts. Make sure the rubber is not broken away from the metal plates on any of them. And they are not soft and spongy from oil. 

If the tranny is shifted to one side, it will put extra pressure on that outer axle joint and as it rotates it will bind on the rear side and push against the steering knuckle causing the steering wheel to turn a little. I know the inner joint slides, but under a load it doesn't slide easy and if the tranny is shifted enough there is no space to slide. The binding doesn't seem to happen on the front of the joint, only the rear. The front axles are angled forward to meet the wheels. On a tight left turn on the rear of the left joint on the left wheel is much tighter than the front of the axle joint on the right wheel.

Hope I explained this ok.

[el_freddo]

Wheel alignment all good? 

Have someone do the turn while you watch the wheel - see if it’s rolling the tyre wall hard then slipping it out again, or if there’s something else at play. 

Suspension bushes good? 

Cheers 

Bennie

[milty60]

I don't hear any sound when it does the odd rolling - it does it when coasting too - I don't feel  the "bump"  in the steering wheel - hard to tell if its happening closer to the hub or inner CVJ - will watch as car makes turn next time my son is behind the wheel - see what the tire looks like in the tight left turn. Alignment is good - need to check bushing - mounts - etc. Will show post replies to my son and check out all the suggestions you guys provided. Axles have never been replaced to my knowledge - my son has had the car for only a year. 

Thanks, 

Milty 

[Rampage]

Check each of the rubber bushings in the front control arms and the rear lateral links. Compare left to right for wear.

Our 95 Legacy would sway on a right curve, but was fine on a left curve. I found the outer bushing was shot on the front lateral link on the left rear wheel.

[milty60]

I'll check it out and follow up. My son also noticed engine idle speed at times is low 300-500 rpm's. If he turns wheel hard left or right it almost stalls - thinking PS pump may be going - wonder if on slow to moderate speed turns its causing that "bumpy" feel my son and I are experiencing. Of course, now we need to resolve idle speed issue - vacuum leak, dirty sensor - please advise. 

Thanks, 

Milty

[heartless]

start with vacuum lines.. they tend to get hard & brittle with age & heat and don't seal well anymore.

[1 Lucky Texan]

you feel 'chattering'/vibration in the steering wheel? that can sometimes be air in the ps fluid, perhaps a bad o-ring on an adapter for the suction hose if the design is similar to my 03 and 06es.

[idosubaru]

Is it low idle all the time or only when symptoms present?

You describe it as if it’s very rhythmic in nature as if it’s drivetrain related and no noise or leaks, so I wouldn’t expect power steering. 

Its a good suggestion to check though. Even more so since the 05-09 legacy power steering pumps are so prone to failure. I think 09 Forster is the same pump.  

Get it to experience the symptoms as much as reasonably possible and immediately get out and look in the power steering reservoir - is it foamy or have any tiny bubbles in it or does it look perfectly clean like it just came from the bottle?

ive seen one Subaru have strained steering due to fluid at 195,000 miles.  Changing the power steering fluid resolved it completely.  This isn’t common though but easy enough to check fluid condition. 

[milty60]

Low idle most of the time - doesn't seem to be related to present symptoms. It does seem drivetrain related but I need to thoroughly drive it around this weekend. Will also check PS fluid condition when symptom is occurring. 

Thanks, 

Milty