Need advice from an E36 expert

[mig25_foxbat2003]

I have an E36 323Ci Cabby in Montreal Blue. It's a little tatty, but it scrubs up OK. I rather like it.



The tyres on the old 15s were resembling the lovechild of Duncan Goodhew and a coot, so I decided to take the opportunity to upgrade to some Style 32 16s with nearly new tyres on them. However, this made the O/S/R wheel scrub the arch over any bumps and whilst taking left-hand bends.

I came to the conclusion that the rear springs had sagged, and replaced them with stiffer SPAX ones (nominally 40mm lower, but in fact, the car sat at about the same height - I know, I know, stupid logic, but it made sense in my head). However, this hasn't fixed the issue, which, if anything, seems to be getting worse.

Having taken a decent look at the car, it appears as though the O/S/R wheel is significantly further back in the arch than its counterpart (probably a finger or two's width difference). Would this indicate that something like the Trailing Arm Bushes are shot, or am I to accept the conclusion that it has probably had a smash at some point and not seen a jig?

Sorry if this is an obvious question - I'm not mechanically minded in the slightest, so need help from experts like you lot. I can take photos of each side if this would help.

Cheers,
Russell

[rassi]

Are you sure all 4 wheels have the same off-set and width? I assume they are non-staggered? If one wheel sits further inside the wheel arch it would indicate that the off-set and/or width is not correct. Do they have an ET number stamped on the inside of the wheel? Could you try to swap front and rear?

[mig25_foxbat2003]

Sorry, I've been unclear and led you down the garden path - the O/S/R wheel is further toward the rear of the car than the N/S/R, rather than being tucked further inside the arch.

[4rephill]

mig25_foxbat2003 said:

Sorry, I've been unclear and led you down the garden path - the O/S/R wheel is further toward the rear of the car than the N/S/R, rather than being tucked further inside the arch.

Definitely sounds as if something is not right!

I've just measured the distance from the rear edge of the tyre to the bottom corner of the the rear arch on the rear bumper on My 328i Sport (The two white lines in the pic below [not My car BTW!] ):




and on both sides the tyre to arch gap is equal at 57mm (245/40/17 tyres fitted).

[TheEnd]

It is likely to be the trailing arm bush, if the arm has slid to the outside, it could rotate the wheel back.
It might also give a horrible feeling on bumps mid corner where the rear will feel like it is stepping out a bit.

Another sign you sometimes get is a tyre chirp when driving over polished manhole covers as the rear wheel scrubs a little.

[mig25_foxbat2003]

Yes, it does do a bit of a second lurch as it "settles" into the corner, but I had attributed that to convertible chassis flex...

I'll take photos later so you can see what I mean, but I'm hoping you're right - RTABs are cheap

ETA - I am currently running 225-50-16s all round, so I should be fine for clearance with this issue aside, yes?

[rossi-328i-sport]

I cant really work out if you mean it sits lower into the arch or whether you mean it is further towards the rear of the car?

If the drivers side rear is deeper in the arch than passenger side then that is totally normal on the E36,it was to compensate for the driver being sat on the left hand side (LHD ,Germany) but is even like this on the RHD E36`s.

i am a member of many E36 forums and this is a massive subject,Some people get hold of thicker springs pads for that particular side, I don`t have the problem now as i have adjustable coilovers now and i was able to balance it out.

[TheEnd]

Your tyre sizes are fine, I used to have 255/40/17s on the back of an E36 without any arch changes, and a mild lower.
It would sometimes rub on a corner with weight in the back, but you'd almost expect that.

[4rephill]

rossi-328i-sport said:

I cant really work out if you mean it sits lower into the arch or whether you mean it is further towards the rear of the car?

He's saying that the O/S/R wheel is physically sitting further back (towards the rear bumper), than the N/S/R wheel does (or put another way, his offside wheelbase is slightly longer than his nearside wheelbase).




As a double check, I've measured the distance from the front edge of the rear tyres to the metal wheel arch where it meets the sill cover:




and the distance on both sides is 42mm, indicating that the wheels should sit in the exact same position in relation to the wheel arch on both sides of the car.

[rossi-328i-sport]

Your RTAB would not cause this although your RTA would, have you had the rear tow set up at all, you might find that it is massively out and can be corrected with the adjustment.

Failing that your actual RTA may be bent if it has had a knock at some point.

[Lloydm]

Dear all,

I have an E36, and some time ago i noticed an annoying vibration, rattling sound coming from the rear. It sounded as if it was coming from inside the car at the back. At first i thought it was the rear shocker mounts. I changed those but it made no difference, they were only £13 each so i wasnt worried. By a process of elimination I concuded that it must be the rear trailing arm bushes. I got a garage to change those and it solved the problem. The tyres then lasted a lot longer too.

My advice is that if the rear trailing arm bushes have gone, then you will probably hear the same vibration/rattling noise that I heard.

Hope that helps,

Lloyd.