I hope some people reading this will have helpful advice on what may be causing a long-standing problem on my 1986 Camry.
On 3/19/04, my engine had stopped on me, and I had it towed to a shop for repair. On 3/23, the shop worked on it and replaced the timing belt, an idler pulley and tensioner. I was able to drive the car again, and did.
However, on the day after the repair, I noticed a new problem: the car would now suddenly and abruptly jerk to the left on increasing speed for just an instant; and it on increasing speed, it would, with a little less force, abruptly jerk to the right on falling speed. It was most noticeable in the
60-70 mph range (not surprising because friction with the road is less at higher speeds), but also at lower speed ranges, too.I suspected something was wrong with the power steering; however, othing was really apparent. I thought perhaps the shop had inadvertently done some damage to the pump during the timing belt replacement somehow; the pump has to be either swiveled aside and "unbelted" (for lack of a better word) or removed to replace the timing belt. However, I did nothing about the problem. There was and never has been any sign of power steering fluid leaking anywhere.
Last spring or summer, I posted a message here explaining my problem, and I was told that "torque steer", a frequent problem on front wheel drive cars, might be my problem. The responses I got at that time, and the literature I found on the Web on the subject of torque steer said that it often occurs when suspension is worn, and is often manifested by problems at the wheel diagonally opposite the corner where suspension is bad. I knew by this time that the shock on my right rear corner was a goner, and that the steering jerk problem I was having seemed to be occurring primarily at the left front wheel. But I didn't use the car a lot during the last half of 2004.
Finally, 3 months ago I had the damper parts of the MacPherson struts on this car replaced; a 4-wheel alignment was also done. I had hopes that this would fix my jerky steering problem. It did not; it's as bad as it ever was. This car is also very hard to keep in alignment, too. A shop will align it and in no time flat it is out of alignment and pulling to the left (it's been a pretty chronic problem on this car.) The front tires are wearing very fast.
I had the idea to detach the power steering belt and drive around for a while without power steering. My reasoning was that if the jerky steering did not happen with the power steering out of service, that I could be sure the power steering was causing my problem. I talked it over with a mechanic, and he advised against it. He said it was potentially dangerous to drive this car without power steering. And he also said that there is sometimes wear in the "rack" which can cause a problem like mine. This car has rack and pinion steering, and the rack is moved by the steering wheel, with, of course, power assistance.
I pondered what the mechanic said, and came to discount his theory of rack wear. For one thing, ever since I first noticed the jerky steering in March `04, actual manual steering on this car has worked fine. Whether I am turning the wheels slightly or a lot, it has been very responsive, with no feeling of looseness or wander in steering. So I don't think there is any significant wear or mechanical hangup in either the steering mechanism or the power-assisted rack.
I read recently that most power steering pumps have a built-in recirculation valve that open should pump discharge pressure get too high. And I got to thinking that maybe there's a problem with my power steering pump's recirculation valve. For there definitely seems to be both a bump-up and bump-down in pressure now that wasn't there 14 months ago.
The problem with that argument, though, is that an abrupt change in power steering pump pressure would not necessarily result rack motion, because with the steering mechanism in a neutral position, an increase or decrease in output pressure would be felt simultaneously on opposite ends of the hydraulic cylinder which moves the rack, and cancel out. Or so I think - perhaps incorrectly.
And for what it's worth, I also see a lot of wear on the rubber cushions where the ends of the stabilizer bar join the control arms. The wear is particularly bad on the passenger (right) side. (Per my Haynes manual, these cushions are inserted to adjust caster during alignment.) Evidently the stabilizer bar is taking quite a beating.
Anyway, this problem has been frustrating me for a long time, and I'm putting it out to the newsgroup for input and suggestions. If I was pretty sure that replacing the power steering pump would fix my problem, I'd do it, but I'm not there yet.
Thanks in advance,
Mike