suspension/ geometry help... finding whats bent

Need technical Q/A then you're in the right place

Moderator: martauto

bmw9818
E30 Zone Addict
E30 Zone Addict
Posts: 2561
Joined: Tue Aug 11, 2009 11:00 pm
Location: Croydon

Post Sun Jun 03, 2018 8:16 pm

evening all,

long story short had an accident back in 2016 someone hit the osf wheel when i was on full lock snapped the tie rod and shifted the rear polybushes, i think? ive just re-aligned them back in

and now working on the front end, however im a bit puzzled as to how to find whats bent?

ive already bought a z3 rack which will be going on with new rods as im assuming the current one took a fair bit of force and it seems to now have play, but its the camber thats the problem, my tracking sheet from when i got the car re-done after the incident is

NSF wheel - Camber -1.53 & OSF -2.08

Caster is -9.30 both sides

Toe is 0.08 NS & 0.09 OS

Total Toe is 0.17

and steer ahead is 0

basically the set up before was absolutely beautiful!!! Did a euro trip and took the car on the ring and a couple of top speed runs had it off the clock and it was absolutely planted and very very stable,

now however i do a 100 and it twitches and its nerve racking, even at low speeds on country lanes it just feels odd, :(

just wondering if someone can help diagnose what may be bent? ive gone around with a vernier and a steel ruler but its a bit just all over the place!

dont really wanna replace a load of bits get it all done up and find out its still bent as im going lemans in a weeks time.. so tryna get it spot on first time
User avatar
M3Pete
E30 Zone Newbie
E30 Zone Newbie
Posts: 87
Joined: Mon Aug 11, 2014 11:00 pm

Post Mon Jun 04, 2018 8:34 am

Did you change the lower wish bone and strut?
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49359
Joined: Mon Jan 10, 2005 11:00 pm

Post Mon Jun 04, 2018 9:44 am

What you describe sounds like incorrect toe to me, rather than necessarily anything bent.
Wind on a little bit more toe in and try it again.
bmw9818
E30 Zone Addict
E30 Zone Addict
Posts: 2561
Joined: Tue Aug 11, 2009 11:00 pm
Location: Croydon

Post Mon Jun 04, 2018 6:29 pm

let me try and upload the tracking sheet, cause ive gone through it but cant really what they adjusted & changed, only part ive changed so far is the outer tie rod i think? or might be inner as well not sure as it was two years back
Last edited by bmw9818 on Wed Jul 04, 2018 7:25 pm, edited 1 time in total.
bmw9818
E30 Zone Addict
E30 Zone Addict
Posts: 2561
Joined: Tue Aug 11, 2009 11:00 pm
Location: Croydon

Post Mon Jun 04, 2018 7:41 pm

Image

Image

Image
bmw9818
E30 Zone Addict
E30 Zone Addict
Posts: 2561
Joined: Tue Aug 11, 2009 11:00 pm
Location: Croydon

Post Wed Jul 04, 2018 7:10 pm

well ive changed the rack new tie rods, new control arm and a new leg.... however front end O/S camber is still -2.02

anyone have any ideas could the accident have bent the chassis?... :cry:

Rear end camber is now -2.36 /2.37 and te is 0.08 /0.05

front toe is both 0.09

NS camber however is -1.53 and O/S -2.02... wtf could the top mount be bent
bmw9818
E30 Zone Addict
E30 Zone Addict
Posts: 2561
Joined: Tue Aug 11, 2009 11:00 pm
Location: Croydon

Post Sat Apr 06, 2019 7:54 pm

bump - still tryna figure this one out, ive taken it to a couple of bodyshops theyve had a look and cant see any visible chassis damage, plan was to get it ona jig to see if bent.. but they ruled it out, and said its something mechanical?

but what else can i change/ look for?
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49359
Joined: Mon Jan 10, 2005 11:00 pm

Post Sun Apr 07, 2019 3:11 pm

Is the car sitting level? A small change in ride height from left to right could cause this small error, which in turn could be caused by the rear end.
User avatar
paultv
E30 Zone Squatter
E30 Zone Squatter
Posts: 1545
Joined: Mon Apr 21, 2014 11:00 pm
Location: Auf dem Schnee: Germany

Post Mon Apr 08, 2019 11:03 am

Have you checked the condition of the bushes and are they fully "home" on the end of the wishbones? Just a thought.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/