This thing handles poorly. Much of that is the tires. The rest is....something? Anyway, I was poking around underneath this past weekend to try to identify the source of the rattle and found something peculiar. Not the rattle.
This is the lower control arm in the rear on the passenger side. There is a bushing pressed into the spindle plus another one that is part of this arm where it joins the rear subframe. Pretty straight forward. This one seems fine, even though there is some rust.
However, when you look at the driver's side, something is wrong.
No idea how this happens. The previous owner doesn't recall any incident that would have made this happen outside of some potholes. I don't think a pothole did this, unless the potole was 14" deep. It was actually hard to see at first, there is a plastic cover that BMW clips over this arm for appearance/aerodynamic reasons. The one from the RH side was missing and the one on the LH side partially obscures the state of the arm. However, it is meant to clip to the space between the halves of the arm. I noticed it didn't appear to be attached correctly, so I removed it to inspect and noticed this problem.
Fortunately, replacement arms are $27 each, so I've ordered new ones. I'll install those this coming weekend provided it comes apart. This explains why the car felt worse turning right compared to turning left. The camber is probably all wrong on the LH side in the rear. I'm also surprised there wasn't abnormal tire wear in the rear, but maybe it's not off by enough to affect that.
01 325Ci Rear Suspension
01 325Ci Rear Suspension
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Re: 01 325Ci Rear Suspension
According to the internet, in order to get the lower control arm bolt at the subframe out, you need to remove the differential.
Sigh.
I'll probably try anyway, but if I have to remove the diff, it only makes sense to replace those bushings too. And if I've gone that far I should also do the rest of the subframe bushings. And if I take that out I should do the rest of the bushings at the spindle. And if that's out I should consider the subframe mount reinforcement kit.
Did I mention yet that these cars are notorious for ripping the subframe mounting points out of the body? There's a nice kit to reinforce that with weld-in plates and another kit for reinforcing the upper strut mount in the rear.
Precision Engineering?
Should I consider polyurethane bushings where available or stick to stock rubber?
Sigh.
I'll probably try anyway, but if I have to remove the diff, it only makes sense to replace those bushings too. And if I've gone that far I should also do the rest of the subframe bushings. And if I take that out I should do the rest of the bushings at the spindle. And if that's out I should consider the subframe mount reinforcement kit.
Did I mention yet that these cars are notorious for ripping the subframe mounting points out of the body? There's a nice kit to reinforce that with weld-in plates and another kit for reinforcing the upper strut mount in the rear.
Precision Engineering?
Should I consider polyurethane bushings where available or stick to stock rubber?
Re: 01 325Ci Rear Suspension
Do some research. Sometimes poly is a great upgrade with little noticeable NVH. Not always though.
Re: 01 325Ci Rear Suspension
The internet is all "racecar" for these cars so that's what everyone is focused on, so it's poly all the way to the track. Or that's at least who is left with these cars. Maybe I should see what people thought 10 years ago when people were buying them as cars still.
Re: 01 325Ci Rear Suspension
Confirmed. The upper bolt does not come out w/o removing the differential. Stupid German cars.
Also, it turns out the lower attachment point is a camber adjustment, so I hope I lined it back up correctly (should have marked it first, but I lined the no-rust line up with the washer, so its probably fine.
Other rear bushings that need replacing:
- LH lower control arm lower bushing (pressed into spindle, the other side is probably equally terrible)
- LH lower control arm upper bushing (comes with the non-bent arm)
- Rear differential bushing (not totally failed, but there are several tears in the rubber that aren't helping)
Also, it turns out the lower attachment point is a camber adjustment, so I hope I lined it back up correctly (should have marked it first, but I lined the no-rust line up with the washer, so its probably fine.
Other rear bushings that need replacing:
- LH lower control arm lower bushing (pressed into spindle, the other side is probably equally terrible)
- LH lower control arm upper bushing (comes with the non-bent arm)
- Rear differential bushing (not totally failed, but there are several tears in the rubber that aren't helping)