2004 X3 sport harsh suspension change

[wub443]

Ok i abandoned the swap to an ML350, too many horror stories of unreliability. I've looked around at other options and don't see anything that comes close to the X3. I have a 2 owner, immaculate 60K 3lt 2004 X3. i like everything about it, apart from the very harsh ride. Tried the Tyre thing, makes little difference.I have spoken to three X3 SE owners, who all said the ride was fine. So i have decided to keep the X3 and change the suspension. by chance there is an X3 SE same year as mine near by being broken due to bust engine.

My question is, what do i need to change, from an SE X3 to my sport X3 to soften the ride? I understand suspension, i've worked on vehicles for years, but i've never had this particular problem to fix. Normally its correcting ride height or lowering / heightening vehicles, or improve corning, i've never had to soften a ride before. Comes with getting older i guess.

so is it the shocks or the springs or both that effect the stiffness of the ride? And do the thicker torsion bars play a part? i'm guessing as they are thicker they may do, or are they just improving under steer on hard corning?

Anybody got some knowledge on this? Please no guesses, i could do that. I'm just interested in proven information!

[mholt1995]

Springs, shocks, tyres (and pressure) and wheels will make the most difference in terms of general ambient ride quality.

RealOEM seems to imply that Sachs were the OEM for at least the shock absorbers.

Product numbers:

Front Left Shock:
Sports Suspension: 31313453523
Non-Sports: 31313453521

Front Right Shock:
Sports Suspension: 31313453524
Non-Sports: 31313453522

Rear Shocks:
Sports Suspension: 33503451404
Non-Sports: 33503451402

Rear Bump Stops:
Sports Suspension: 33503413808
Non-Sports: 33503404974

Can't find anything on the springs unfortunately.

[Kawasicki]

Look at changing suspension bushes too. I would speak to a bmw dealer parts desk to get a handle on what part numbers are required. Sometimes springs and dampers can be vehicle specific... that means that spring stiffness changes depending on spec of vehicle. So a car with a sunroof might have slightly stiffer springs than an otherwise identical one without.

[samoht]

I understand the front suspension on these is MacPherson strut, i.e. the spring, damper and bump stop are combined in a single strut unit at each corner, I suspect the easiest and best thing to do will be to unbolt the whole strut from the donor and swap it over. This also avoids messing around with spring compressors.

Given you're doing that, and based on what's been posted, I'd imagine best to swap at least the springs and dampers at the rear also, and as above the bump stops too.

I'd also swap the smaller SE wheels and tyres, assuming they're available and the donor's tyres are decent.


So the only remaining questions are the difference or not of the front and rear anti-roll bars.