Update 7/14/19: It actually turned out to be low and old/dirty transmission fluid. It’s a Subaru all wheel drive, issue went away when only FWD was enabled. Did a drain and fill of transmission fluid 4 times and the issue is fully resolved.
There was a bout of torrential downpour and lightning here the other day that is not common. I drove to a store and there were certain locations with high water across the road. Even a spot on a main/busy road had high water.
The next day when turning, more noticeably at low speeds, the wheel area started to jerk. Like it would be fine for a second then was like something was stuck in the wheel and would repeat that.
I thought something must have happened to the wheel assembly area. Then I thought maybe water got in the timing belt area causing it to slip as the timing belt cover has been off.
I read online people saying stuff about the power steering pump.
I took it to a parking lot to try and experience it more clearly. Only when turning it was like there was major front suspension damage.
So I decided to get out and check the power steering fluid level. Maybe it was low or leaked. Checked it twice and it was at full.
Got back in the car and the issue was gone! Apparently air had become trapped in the power steering system after driving through high water, and opening the cap let it out.
Easiest simplest fix. I thought it was going to be hard/time consuming to diagnose.
+1
Additionally, the OP should be aware that the timing belt–which is “cogged”–will not slip unless there is a mechanical problem, such as a bad belt tensioner. And, if the timing belt had slipped, the engine would now be running… very badly, or perhaps not at all.
As PvtPublic stated, this sounds like the placebo effect in action.
Someone correct me if I’m wrong here but every hydraulic power steering system that I know of continuously circulates fluid freely to the steering gear and back until the wheel is turned causing the flow to be blocked and diverted to move the gear. When the wheel is turned with the pump not operating fluid will be pushed forward through the return line possibly blowing out the fill cap vent.
Could Subaru have a unique system different than all others?
Well when I say transmission fluid I’m talking about the actual transmission. The power steering system also takes transmission fluid. There is something called torque bind that occured that has to do with turning and the all wheel drive system. One of the main causes I found is that it is caused by dirty ATF fluid.
I know mine had not been changed in over 30k miles. There was also two different times I lost some fluid while working on the car, I did not add more after and those occurrences were awhile ago.
I had no issue with turning until suddenly one day.
I didn’t realize it was that low on transmission fluid because apparently the dipstick is suppose to be used when the engine is running and the hot/cold lines have to do with the status of the transmission itself.
I did the drain and fill, as recommended on the forums and that solved the issue. $42 in ATF fluid instead of $120 “professional” flush.
I think there would have to be considerably much more pressure for the fill cap to be blown out. I don’t know what you mean by fill cap “vent”.
In your other tread you stated that the harmonic balancer was slipping, this would no doubt be a greater problem when the harmonic balancer gets wet driving though flood water. The power steering won’t function if the pulleys stop turning.
Good job on changing the power steering fluid… but I agree it is probably the belt that slipped. (Is it getting worn?) It sounds like it’s working well now.
Any way, you probably saved more than $120. I checked w/ the dealer and he gave a similar price… for each flush. I’m surprised it was that dirty after 30K miles. You flushed with, what, 2 gallons of Dexron III? (I generally drain, then wait a week to drain again, if needed.)
3-4 gallons of Walmarts Supertech ATF. I’m quite sure it was torque bind because I found others describing the same issue on a Subaru, having the All Wheel Drive system. It has to do when turning how it compensates the speed of the rear wheels to the front. When I put the fuse in for FWD only the issue went away, which is what others having the same issue experienced.
I just did the drain and fill, diving a little bit in between which is what was advised from what I found.
I think the issue was more of that it was low on fluid. I know some came out last December when I removed the radiator to replace the water pump and do the timing belt for the first time.
Also a couple months ago when I removed the engine and then before reinstalling had to get the torque converter right, which has ATF in it there was some lost then.
Ah, sorry, I overlooked the low on fluid. If low enough, that can
cause probs. It could have been a combo of events. A slipping belt
might cause surges, that could suck air bubbles.
Any way, it's moot. I am glad your car is back in service. Well
