Jetto Posted February 10, 2020 Report Share Posted February 10, 2020 Good evening, I’d like to bring my BMW down to you guys however I have a few queries about some handling issues ahead of me booking in. Relevant spec of the car is that it is the xdrive all wheel drive, has the adaptive dampers (comfort/sport stiffness), standard staggered 18 inch wheels with Bridgestone runflats (rears are well worn but legal, fronts at least 4mm). I have a brand new set of Michelin Pilot Sport 4 BMW spec runflats that I’d want to get fitted ahead of a geo though. 86000 miles for what it’s worth to give an idea of component wear. Issues I have include: 1) steering wheel is left hand down when travelling straight ahead, 5-10 degrees perhaps. Enough to be an annoyance 2) it has a tendency to drift to the right slightly on motorways although it tramlines in either direction 3) on centre steering and mid corner feel is dreadful. Have to make corrections which have no real feedback. I guess this has something to do with poor EPAS calibration and nothing can be done? 4) bumpsteer is woeful. It pulls/snatches the steering wheel over any undulation and is particularly noticeable under braking 5) I can’t be sure but over rough roads it can sound like a front end damper rattle. Less prominent in sport setting which leads me to believe adaptive damper valves rattling instead of top mounts. I’ve read that a later software update has cured this for some people. Of course it could well be something totally different. Would you advise a 4 wheel geo and new set of tyres to help solve some of the above? Happy to take your advice on any suspect suspension components while I’m there too. Many thanks, Oli Quote Link to comment Share on other sites More sharing options...
Tony Posted February 11, 2020 Report Share Posted February 11, 2020 Welcome Are you on the run flats all round at the moment, Also was there a time it drove better than now and if yes what was done in-between? Quote Link to comment Share on other sites More sharing options...
Jetto Posted February 11, 2020 Author Report Share Posted February 11, 2020 Hi Tony, Yes it’s on run flats all round at the moment. The new set of unfitted Michelin’s I have are also runflats. I’ve only owned the car for 4 months and covered 2-3k miles so I can’t vouch for when it last had a geo setup. Nothing’s changed in my ownership regarding its handling characteristics, it’s had the same characteristics since I bought it. Thanks, Oli Quote Link to comment Share on other sites More sharing options...
Tony Posted February 12, 2020 Report Share Posted February 12, 2020 Ok this is how i see things. 1: Is a geometry issue and an easy fix 2: Is the tyres 3: Is the tyres. The RFT has next to no tyre slip angle. This is the movement between the bead area and the tyres contact patch. 4::Reads like the front control arm bushings are worn. 5: I doubt the damper is worn because it's not a regular complaint. it could be the control bushing again or maybe a drop-link. I re-wrote the geometry for the rear because BMW got it wrong for the RFT. Quote Link to comment Share on other sites More sharing options...
Jetto Posted February 13, 2020 Author Report Share Posted February 13, 2020 Hi Tony, Thanks for the pointer about control arms. I’ve done some reading and seems quite common for the oil filled hydro bushes on the control arms to wear out or sometimes start leaking. I’ll find some time to take the wheels off and see what condition they’re in, but might be worth me renewing them anyway before I come for an geometry alignment. Would you recommend sticking with original BMW replacement arms or do you recommended any aftermarket brands? Thanks Quote Link to comment Share on other sites More sharing options...
Jetto Posted February 26, 2020 Author Report Share Posted February 26, 2020 Hi Tony, I finally got round to taking the front wheels off to have a look at the bushes. The control arm bushes have about 3 or 4mm of play when twisted by hand. When using a pry bar they move quite a lot and feel very jelly like. There doesn’t appear to be any fluid leaking from the bushes but the surfaces show minor cracking starting. I have put a video on YouTube if you wouldn’t mind taking a look and let me know your thoughts? A pair of new arms from BMW is £300 so I’m a bit hesitant to bite the bullet on getting new ones. https://youtu.be/C5MCBuMZxQQ Photo below shows some minor surface cracking in the bush. Thanks, Oli Quote Link to comment Share on other sites More sharing options...
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