hdaemon
08-22-2005, 12:23 PM
Car: '90 535i 5spd, 205k Miles
Issue #1: Moderate vibration at 65-80mph.
At highway speeds, I get a moderate amount of vibration in the vehicle. I feel it mostly through the seat rather than the steering wheel, and it's visibly noticeable through the gearshift lever. The vibration has been there for a while, and exists independantly of the set of wheels/tires that are on the car. Above about 80mph or so the vibration settles down and smooths out.
My initial presumption is that it may be a bad set of upper control arms, either the bushings of the arms themselves. The PO had the bushings replaced several years ago with the 750i bushings, but kept the old arms. I'm not sure on the exact number but I think probably ~5yrs and 50-60k or more ago. How long do the 750i bushings last? Or might it just be that the ball joints are going bad?
If I replace the arms myself, is an alignment needed after reassembly?
Issue #2 - Soft rear end
An issue that has arisen in the last couple of months is that the rear end has started to feel really soft, particularly on the left side. It feels almost as though the rear left tire is low on pressure, even when it isn't. The left side of the rear seems to be sitting about 1/4-1/2" lower than the right. Also, when driving on concrete (ie- into/out of the parking garage at work), that the rear left tire squeals at every opportunity.
Having had the dogbones replaced <10k ago, and a new set of Bilstein HDs ~25k ago, I'm guessing that I might need a new set of subframe mounts?
If that's a likely possibility, how difficult a job am I looking at? I'm reasonably decent with a wrench, and have easy access to workspace and most any tools I'll need. My primary concern is the bushing puller. Is this a case where only the genuine BMW tool will work appropriately, or are their acceptable substitutes, and if so, what are they? This is a situation where I would be able to work all weekend on the problem, but would need the car back together for monday.
Issue #1: Moderate vibration at 65-80mph.
At highway speeds, I get a moderate amount of vibration in the vehicle. I feel it mostly through the seat rather than the steering wheel, and it's visibly noticeable through the gearshift lever. The vibration has been there for a while, and exists independantly of the set of wheels/tires that are on the car. Above about 80mph or so the vibration settles down and smooths out.
My initial presumption is that it may be a bad set of upper control arms, either the bushings of the arms themselves. The PO had the bushings replaced several years ago with the 750i bushings, but kept the old arms. I'm not sure on the exact number but I think probably ~5yrs and 50-60k or more ago. How long do the 750i bushings last? Or might it just be that the ball joints are going bad?
If I replace the arms myself, is an alignment needed after reassembly?
Issue #2 - Soft rear end
An issue that has arisen in the last couple of months is that the rear end has started to feel really soft, particularly on the left side. It feels almost as though the rear left tire is low on pressure, even when it isn't. The left side of the rear seems to be sitting about 1/4-1/2" lower than the right. Also, when driving on concrete (ie- into/out of the parking garage at work), that the rear left tire squeals at every opportunity.
Having had the dogbones replaced <10k ago, and a new set of Bilstein HDs ~25k ago, I'm guessing that I might need a new set of subframe mounts?
If that's a likely possibility, how difficult a job am I looking at? I'm reasonably decent with a wrench, and have easy access to workspace and most any tools I'll need. My primary concern is the bushing puller. Is this a case where only the genuine BMW tool will work appropriately, or are their acceptable substitutes, and if so, what are they? This is a situation where I would be able to work all weekend on the problem, but would need the car back together for monday.