BMW E36 3 series handling problems, i'm stumped

[g40jon]

My BMW e36 318is coupe has developed a weird handling problem. The car feels like the rear end is steering when accelerating or deccelerating. It's especially noticeable when changing gear, where there is a noticeble twitch from the back end. It almost feels like the rear axle is moving around and is much more noticeable in the wet than it is in the dry.
In the past year I have replaced all 4 shocks and springs (meyle rear shocks, jom coilovers up front with meyle top mounts), new meyle drop links, poly-bushed ARB, replaced the front lower arms so I am pretty sure the problem isn't coming from the front of the car.
I have had the rear up in the air and can't see anything obviously wrong. It went through an MOT with the twitchy handling. If it were a failing bushing I would have expected my mate who did the mot to pick it up and he is very fussy.
I am at a loss as to where to look next. Current thoughts are to replaced the trailing arm bushes where the arms bolt onto the body.

Any help would be super appreciated as it is spoiling my love for the car.

[Deleted]

Rear trailing arm bushes need replacing. Not necessarily totally broken,but too soft

[g40jon]

Dec 27, 2018 20:26:38 GMT @johnnybravo said:

Rear trailing arm bushes need replacing. Not necessarily totally broken,but too soft

That's my thought too. I've ordered some flo-flex poly replacements as i've found them to be pretty good on my mx5 and its also the brand i've used on the bmws arb bushing.

thanks!

[slammage]

yep gonna be the RTAB, as said.

I replaced mine with just the cheap ish black poly ebay ones, done the job and although showing some signs of minor cracking they weren't obvious to spot either. I would just do them in the near future to any other e36 I own just because really:)

[slammage]

also get your tracking re set by a proper outifit afterwards. will iron it all out hopefully

[ChasR]

The handling issue will be down to two things>

1) Rear Trailing Arm Bushes : these will cause the same issues you are having. For this application, I'd fit either Genuine M3 bushes sourced from Cotswolds, or a set of PowerFlex or SuperPro bushes. The latter two can be a bit of a pig to fit but a mini-vice or some studding and washers works wonders

2) Rear Subframe bushes. This is less likely, but my M3 had the same issue. It's hard to say whether it was rear steering, but it did have a strange twitch on the motorway etc.. You needed some brave pills going over the white lines, it was that sketchy!

I was convinced it was my front tyres causing it. When I had the boot floor reinforced I also had some SuperPro subframe bushes fitted. That transformed the rear end. The stock bushes can be changed in situ with a special tool as an American poly bush. Others will require you to lower the subframe.

I second that you should take it to a good alignment shop. I wouldn't go to one just because they have decent equipment too. On my E36 323i, it never felt as nice as my M3 to drive, despite being near enough on brand new suspension as you can see here; It never felt planted; annoying considering my mate spent a fortune changing the suspension on it. Since you are close to Warwick, I can recommend Spire Technologies in Warwick. Matt really knows his stuff and is very well respected in the M3 circles; his day job is being a chassis engineer for Jaguar Land Rover. He's not too crazy with his prices either compared to certain outfits; he wanted £30 more than Pro-Tyre who I had it done from, and they re-did it twice (the first time, they got the steering bent). And yes, Pro-Tyre were very quick to say that he had £70,000 worth of Hunter Alignment gear. I only went there as my trusted bloke's SuperTracker gauges wouldn't go over the wheels due to my car being lowered.

www.spires-st.com

[v8ian]

I would go for rear subframe bushes, my E39 had similar issues.

[giuliettaevo]

E39 has a totally different setup. On an e39 all the suspension hangs of the rear subframe so if those bushes are shot your entire axle is moving about. On the e36 that's not the case.

[ChasR]

Dec 28, 2018 23:12:56 GMT giuliettaevo said:

E39 has a totally different setup. On an e39 all the suspension hangs of the rear subframe so if those bushes are shot your entire axle is moving about. On the e36 that's not the case.

It will still affect the car. With shot subframe bushes, the toe will change as the subframe moves above, due to the RTCAs being attached behind the sill, and the rest of the multilink setup being attached to the subframe. I'm pretty sure the E39 has RTCAs too attached to the car but I'll double check.

E36 and E46s are very similar setups. After all, the E46 was the evolution of the E36.

As said, on my M3 changing those made a massive difference. It was like I drove out with another car. I would never relax on a motorway trip until I had that done.

But the RTABs are a common and easy thing to change.

[g40jon]

Thanks for ll the advice. I will let you know how I get on.

[Ian]

Have a look at the rear wheel, if they look like they are toeing in at the front its points to the RTAB's

We had a 325ti E46 that used to wander at speed ( it was almost like it wanted to change lanes all on its own) and that was down to the subframe bushes on that one, they do tend to go through bushes more than some other cars.

[g40jon]

Jan 2, 2019 15:55:35 GMT Ian said:

Have a look at the rear wheel, if they look like they are toeing in at the front its points to the RTAB's

We had a 325ti E46 that used to wander at speed ( it was almost like it wanted to change lanes all on its own) and that was down to the subframe bushes on that one, they do tend to go through bushes more than some other cars.

Whe I first got the car it scrubbed the rear tyres out very quickly much to my annoyance. you could visibly see them pointing inwards. My mate slacked off the mounts and reset it as best as he could, but did say he couldn't get it spot on. Tyre wear is even since. I will have a look at the subframe when we tackle the RTABs. Thanks!!

[Ian]

Jan 6, 2019 22:17:40 GMT g40jon said:

Jan 2, 2019 15:55:35 GMT Ian said:

Have a look at the rear wheel, if they look like they are toeing in at the front its points to the RTAB's

We had a 325ti E46 that used to wander at speed ( it was almost like it wanted to change lanes all on its own) and that was down to the subframe bushes on that one, they do tend to go through bushes more than some other cars.

Whe I first got the car it scrubbed the rear tyres out very quickly much to my annoyance. you could visibly see them pointing inwards. My mate slacked off the mounts and reset it as best as he could, but did say he couldn't get it spot on. Tyre wear is even since. I will have a look at the subframe when we tackle the RTABs. Thanks!!

I have had new RTAB's and set of cheap coilovers sat in the boot of mine for the past 8 years! When it was still on the road I tried to change the bushes, and could only get the mount out, but could get the bolt out that goes through the bush!
One day I will get the car out of the garage and have another look at it! I had visible rubber on the rear bumper due to the speed which the tyres wore out when it was still being used.

[toast00]

Where the RTAB mounts to the body is a bit of a rust spot. Make sure the cup-mount that the RT bushes mount to isn't also flexing due to rust.

Second to that i would also agree with the subframe bushes where the diff mounts.

I changed everything on my E36 years ago with OEM Lemforder bushes and was amazed how new the car felt again.

[g40jon]

Changed the rtab bushes and hey presto the car now drives like a different motor. Chuffed to bits! the old bushes had ovaled and you could see where the metal pin had been rubbing and looked polished as a result!
thanks for the help