Steering has a mind of its own.What is broken?

[jehu]

Twice now I've felt the car act as if I was in a seriously "rutted" road way where no such ruts were evident. It felt like the car just began drifting off to one side on its own..

First time I put it down to road surface anomaly I just couldn't see because of the dark. Happened again tonight and while it may have been weird road surface since it was dark and I was doing 75 mph I can't say for sure..

I'd describe it as feeling like the steering control just gave way and the car floated off hard to one side..

Anyone have an idea where to look?

[filmy]

Not sure what you're runnin', Jehu, but wider tires are much more inclined to grab the shallowest ruts in the pavement and pull the car all sorts of directions - ruts you can't even see. Unless your steering does that pull frequently and on different road surfaces, I wouldn't worry about it.

[stoney85]

also known as 'tram lining' where it follows the road contours

Can also be caused by an incorrect wheel alignment, where the toe settings are wrong, actual readings i'm not sure of, whether it's positive or negetive toe that can cause it

Other things might be a stiff/worn ball joint in the drag link or other steering component, that catches on a bump and doesn't settle in one position - changing the geometry

[jehu]

235/45/17 x8.5 X4... Had an alignment recently with wheel balancing.. I can take it back to the shop to have them look at it again.

Had the center link ,idler arm and pitman arm replaced last Spring, six months ago..

Guess I'll get it up on a lift and get a good look at everything.. would broken Rear Subframe Bushings and or Mounts produce this sort of behaviour?

Really its just happened twice to such a degree that it surpised me I think if there were something like a ball jpint or tie rod at fault it;d be much more regular..

[Sherman]

It sounds like road ruts. When they aligned it they may have set the toe close to neutral, which is great for turn in snap, but it will tram, especially with 235s. You're lowered a bit too, no?
Rear subframe or RTABs will manifest as a clunk on bumps, and feel like the rear end suddenly stepping out on you in a corner. I don't think you have anything to worry about. Does it only happen in the dark? Maybe it's squirrels... :P

[jehu]

It sounds like road ruts. When they aligned it they may have set the toe close to neutral, which is great for turn in snap, but it will tram, especially with 235s. You're lowered a bit too, no?
Rear subframe or RTABs will manifest as a clunk on bumps, and feel like the rear end suddenly stepping out on you in a corner. I don't think you have anything to worry about. Does it only happen in the dark? Maybe it's squirrels... :P


You mean Chipmonks? lol.. so far it actually has been dark both times I felt this and only since the alignment... thanks for the info.

[skylinergtr]

my steering has a mind of its own too... It swerves when there is an incline. I replaced the front end, and the idler arm. Got an allignment and sometimes i still have to put my steering does not go straight when there is an incline somewhere.

[MarchelloBB]

Mine always turns a bit to the right, but i'll get the alignment done when I get my winter tires

[Binjammin]

$5 or a nice beer says it's a worn idler arm.

[ShapeShifter]

Have you checked the rear dogbones?

[garrettpier]

my bet is on over sized wheel tire combo. I had similar issues, tried most solutions--like chasing a ghost. replaced entire front end, rear dogbones, alignment, balance, new tires; still tram lining. So i put the stock wheels back on and all problems are gone. no shimmy no tramming, no wierdness-- makes me feel dumb for messing with all that stuff over aversized wheels. I mean they look great but if the car drives with a mind of it's own you have to ask " are they worth it?".

[Binjammin]

Jehu, any idea what brand idler you installed? I'm guessing the wheels+tires were on long before the issues showed up. A rear subframe going bad will usually feel like the rear is wandering while you go down the road, not so much of the rutted road feeling.

[mikemxbike4]

My car also wonders all over the road like crazy. Some roads thet are uneven make the car jump all over the place. I checked my front suspension and havent found anything worn. And my alignment was set recently. Id love to solve the issue, but im not sure whats causing the problem.

[whiskychaser]

would broken Rear Subframe Bushings and or Mounts produce this sort of behaviour?

I had similar problems which were most noticeable on the motorway at speed. Come to a gentle bend and correct the steering. Car responded but then it felt like it had changed its mind and decided to go straight on so had to correct again. If you put mine in park and rocked the car, you could actually see the front of the subframe dip:-( New rear subframe bushes sorted the 'rear steer' problem.

[garrettpier]

would offset have any affect? I mean the geomatry is designed around et20 so if you add a large wheel with an offset that allows the said large wheel to fit-- et13-- wouldn't the added leverage on the thrust arm cause the car to "tram line" under certain conditions.

I don't know for sure about this. i have just come to this idea myself trying to get 18''s to work. I gave up. to much work.

is there a solution?

[jehu]

Jehu, any idea what brand idler you installed? I'm guessing the wheels+tires were on long before the issues showed up. A rear subframe going bad will usually feel like the rear is wandering while you go down the road, not so much of the rutted road feeling.


Yea the wheels and tires have always been the same..

Now that I think about this I had the center link and pitman arm done together when removing the idler arm the bushing was difficult so it was also replaced I don't recall at the moment if the existant idler arm was reused or if a new arm was installed as well as the bushing but I do know the bushing was done then . I'll see if I can get the brand..

Honestly the way I think best desrcibes this sensation is as if the tie rod ends were loose imagining they weren't threaded onto the rod and the wheel just went off in another direction while I was otherwise going straight ahead, not that It steered right or left when I was turning the steering wheel in another direction. it wasn't subtle at all it scared the crap out of me as I was on the highway in traffic and wondered if I was going to loose steering altogether.. when I had room I cut the wheel back and forth to establish that I had steering control and there was no obvious disconnect so I carried on and figured it was an invisible road rut but I had to ask because I'd think it would happene much more often if it was nothing more than road ruts.. the idea about the new alignment specs sounds reasonable since its the most recent change and this wasn't an issue before. I'll swing back to the shop (Town Fair Tire) and see what they think.. The tire size is among those listed on the B pillar. I wouldn't think they'd be listed if they alone were known to cause problems..

[sfgearhead]

Yea the wheels and tires have always been the same..

Now that I think about this I had the center link and pitman arm done together when removing the idler arm the bushing was difficult so it was also replaced I don't recall at the moment if the existant idler arm was reused or if a new arm was installed as well as the bushing but I do know the bushing was done then . I'll see if I can get the brand..

Honestly the way I think best desrcibes this sensation is as if the tie rod ends were loose imagining they weren't threaded onto the rod and the wheel just went off in another direction while I was otherwise going straight ahead, not that It steered right or left when I was turning the steering wheel in another direction. it wasn't subtle at all it scared the crap out of me as I was on the highway in traffic and wondered if I was going to loose steering altogether.. when I had room I cut the wheel back and forth to establish that I had steering control and there was no obvious disconnect so I carried on and figured it was an invisible road rut but I had to ask because I'd think it would happene much more often if it was nothing more than road ruts.. the idea about the new alignment specs sounds reasonable since its the most recent change and this wasn't an issue before. I'll swing back to the shop (Town Fair Tire) and see what they think.. The tire size is among those listed on the B pillar. I wouldn't think they'd be listed if they alone were known to cause problems..

Definitely check all the steering components, pitman and idler arms, links etc.

You might also check the steering shaft to intermediate joint to see if it has loosened up over time. Grab the steering shaft above the box and see if it has any play. If it does tighten the 32mm nut on the steering column.

http://www.bmwe34.net/Wiki/tiki-index.php?page=Steering+play

It's possible that by fixing a few components you're now putting more stress on the new weakest link in the system.


would offset have any affect? I mean the geomatry is designed around et20 so if you add a large wheel with an offset that allows the said large wheel to fit-- et13-- wouldn't the added leverage on the thrust arm cause the car to "tram line" under certain conditions.

I don't know for sure about this. i have just come to this idea myself trying to get 18''s to work. I gave up. to much work.

is there a solution?

Offset has a huge effect. You're increasing the leverage on the suspension components, which at this point for most e34's are probably due for replacement.

High performance tires with stiffer sidewalls also make things worse. As do shorter sidewalls like on the 18" wheels.

I sold off a mint set of AC Schnitzer 8.5x17 wheels with a 15mm offset because it tramlined like crazy. Roads here in the PNW are badly rutted due to studded tires. With stock e39 8x17" wheels with a 20mm offset I have no issues (also running Pirelli high perf all season tires).

Back to the OP, it's likely either an alignment issue, or the next weakest link in the chain. Listen to Bin, he's right more than most of us, and has more experience than most of us. Good luck, doesn't sound like fun.

[jehu]

Definitely check all the steering components, pitman and idler arms, links etc.

You might also check the steering shaft to intermediate joint to see if it has loosened up over time. Grab the steering shaft above the box and see if it has any play. If it does tighten the 32mm nut on the steering column.

http://www.bmwe34.net/Wiki/tiki-index.php?page=Steering+play

It's possible that by fixing a few components you're now putting more stress on the new weakest link in the system.



Offset has a huge effect. You're increasing the leverage on the suspension components, which at this point for most e34's are probably due for replacement.

High performance tires with stiffer sidewalls also make things worse. As do shorter sidewalls like on the 18" wheels.

I sold off a mint set of AC Schnitzer 8.5x17 wheels with a 15mm offset because it tramlined like crazy. Roads here in the PNW are badly rutted due to studded tires. With stock e39 8x17" wheels with a 20mm offset I have no issues (also running Pirelli high perf all season tires).

Back to the OP, it's likely either an alignment issue, or the next weakest link in the chain. Listen to Bin, he's right more than most of us, and has more experience than most of us. Good luck, doesn't sound like fun.


I'm off to the alignmnet shop and I'll ask if they'll let me under the car to check the steering.. though on the big V8 I don't ever recall seeing the steering shaft except in pictures,lol...
**UPDATE**
Bin had something with the Idler Arm Bushing... There was a substantial amount of play when up on the lift in the right wheel traced directly to the Idler Arm Bushing.. the Bolt was tight but was wiggling inside the bushing.. I remembered that I supplied the part to the shop when they also put on the TRW Center Link I furnished. They called me saying they were unable to remove the old idler arm bushing so they had to order a new idler arm into which they installed the bushing I suplplied.. I am a Lemforder First kind of guy when it comes to suspension/steering parts where applicable and they do make this part but I can't find my receipt for it so I may have cheaped out thinking someting stupid like;" How can you screw up making an idler arm bushing...?"

They also said the alignment was still correct and changed nothing.. I can take a picture of the print out of my alignment specs if anyone is interested..