copied for info from BF: 1990 535 E34, Steering box output shaft
What options are available for taking care of sloppy steering caused by excessive play at the pitman arm. The pitman arm does not appear to be loose on the shaft, the bolt is tight so I cant envision it has worn at the splines. Is there a bearing that could have worn or would it be more likely the output shaft itself? A new replacement steering box is too expensive, the best price I have found for a rebuilt unit is around $450-500 CAD ($164 US + 89 + duties + core charge, I might as well bite the core charge of 100 US. due to the cost of shipping). Furthermore I have read that these rebuilt units don't necessarily have worn parts replaced.
Are you sure the pitman arm is tight on the splines? My experience is that pitman arm slop can be medium-bad in use but still un-reproducable by hand (wiggling it), at least when installed on the car. I detected it by clamping vicegrips vertically on the pitman arm, turning the steerbox input by hand (from underneath), and observing the vicegrips incorrectly rotating around the Y-axis (front-back wrt. the car) before correctly swinging with the pitman arm around the latter's Z-axis (up and down wrt. the car). The vicegrips amplified the slop enough to see it. In my case, I was able to crank down harder on the pinch bolt, being very careful to feel for yielding as I exceeded the torque spec significantly, and that cured the problem as of 3 months ago.
I would expect radial play in the sector shaft (steerbox output) would cause a massive fluid leak. I've also never seen this particular type of wear on any steering gear. In decreasing order of frequency, steerbox slop - other than inherent flaws in the design (the recirculating balls, mostly) - seems to be 1. sector shaft lash (the main adjustment they all have, including ours), 2. worm shaft lash (not adjustable on ours), and 3. pitman arm splines loosening. Morozza
If the weather is good on the weekend I've got to check the same thing, but bonus the steering is on the exhaust side plus I have an older car with a battery tray on that side too.
I have a slight knock on the steering as well. I found it because even though I have replaced all suspension I still have a loud knock over bumps. I can't make the suspension knock while shaking and pounding my parked car though. I can make the steering knock with the wheels up on stands, but it's no where near as loud as I hear when driving on bumpy roads so I'm not sure that's it but welp, you gotta have a hobby I guess...
Either my steering shaft/box or pitman arm is faulty (knocking noise comes from that side) or my new suspension is stuffed and I did something wrong on that side? While replacing the idler arm a few weeks ago I checked out the centre arm ball joint for the ptiman arm and that seems OK - the only thing I haven't replaced. At least tackling the steering and trying to fix that works on the process of elimination principle
I had a knocking noise that drove me before I discovered it was exactly what Moroza described. My pitman arm was moving up and down on it's shaft, and were it not for that little plastic piece under it, would have come right off the steering box. I never did locate a torque spec for it, but tightened the heck out of it and the noise went away , and my steering tightened up quite a bit. Given your symptoms, I would guess you're having the same issue. I should have mentioned that the pitman arm only moved on the output shaft when I went to full lock in either direction. The pinch bolt was tight, and everything seemed fine until I cranked the wheel over to lock. It moved up or down a lot at lock. That plastic piece I mentioned seems to be there just to prevent catastrophic steering loss due to this issue, so BMW was aware that this could be a problem. Anyone having a knock in their steering at lock should check this!
No I am not sure the pitman is tight on the spline, I assumed it was, because the pitman arm bolt is very tight. Of course it would help if the subframe didn't restrict the view. My first thought was the pitman arm worn at the spline, but mine moves so much that I thought it had to be the shaft otherwise the spline would be stripped. I just put it up on the jack stands and am going to see if the bolt will tighten.
I have 1/2" play at my front wheels, so if I move the wheels back and forth I can see the pitman arm move up and down considerably. I haven't heard any knocking noises though...
Well I'll be damned, that was it. Thanks Moroza!!
The knock over the bumps could be the sway bar links. Sometimes not obvious to see when up on jacks.
yes, knocking is usually sway bar links
this is basically all what can fail
Center tie rod also to be checked.
center tie rod, Important info for our members from RHD and LHD countries
should it have play or not?
also check this