Rear Suspension Troubles
 

I've recently acquired a 2003 4.6is imola rot with relatively low miles (well the lowest mileage old bmw I've owned yet lol). At 110k miles when I purchased it I've been slowly combing through the truck to get it back to proper road tripper status. Anyways the truck is on OEM sized tires on style 87s. 9.5" wide front rims and 10.5 wide rear rims with 275 somethings up front and 315/35/20 in the rear. Now the previous owner did a air to coil spring conversion which I'm not a fan of since they went with cheap Chinese parts. Ever since I owned it it's had an annoying rubbing noise in the rear passenger wheel area. I found the aftermarket spring is rubbing up against the chassis on the outer wall of the area the spring goes up into. I plan to convert the car back to OEM air suspension as I already have most of the parts on hand and have new arnott airbags. I also removed the previous owners rear wheel spacers as I was getting some awful rear camber wear too. After removing the spacers i now have just the passenger rear tire occasionally rubbing on the inside part of the chassis. Now I know the rear suspension needs a refresh of sorts so I decided to purchase adjustable rear camber and toe arms from silver project eu. I'm hoping this will solve my uneven tire wear issues. However I'm concerned that when I install the new air bags in the rear that the air bag might still rub on the chassis. Has anybody else ever had any issues like this before with rubbing on stock wheels and tires? I don't want to put the new bags in and then have the passenger rear blow out because it's rubbing against the chassis too much.
There were no Carfax reported accidents, the truck was taken care of relatively well until it seems about 80-90k miles as it had some sort of CPO contract and got some things replaced under that but unrelated to the suspension. To be clear it's quite a multi part problem the inside of the rear passenger tire only runs on the inner chassis wheel liner, and the spring itself that was added for the coilvoer conversion rubs on the outer part of the chassis right where it begins to go up by the mount

Is it possible I need new subframe bushings and that the frame could have shifted over, is that common? Or can really badly worn rear control arms cause stock tire rubbing on the inside of the wheel well? Would this also cause the spring to rub on the chassis or could that just be a case of installation error? I can't imagine it to be that hard to position the spring on the perch correctly and what not though, although the most recent owner has surprised me many times with their hackjobs on the rest of the truck.

In addition to converting back to OEM rear air suspension I'm planning to replace the rear shocks, shock mounts, and add adjustable upper and lower control arms for rear toe and camber adjustments. Will this be enough to solve my awful rear tire wear and rear end rubbing noises?

There rear tire wear is almost always from the ball joint on the wishbone link being worn. You can have 3° of neg camber without wearing the tire it's the negative toe while braking that causes the wear.

There was a recent thread where somebody that added adjustable links had rubbing like you described and figured out a fix. Factory links will not rub with any of the factory size tire options.

Also: unless there is some damage you will be able to get the car adjusted to spec without special arms unless you lowered your car it's the only time I'm aware of where the special arms are needed.

I've never seen an example of "can't get to spec" and "too much neg camber" that was inaccurately blamed on inside tire wear that wasn't either the wishbone link or the rear ball joint or both.

If the wishbone link is shot, it can be possible to still align the suspension when not moving but when you hit the brakes the loading of the suspension will steer the wheels outward add much as 2° and eat through tires very quickly.

When I replaced mine, I could move both the bad joints over 1.5mm that equates to well over 1° of steering motion!

I can't remember the exact trick the guy used to fix the rub but I would cross that bridge if it comes up. It should cure itself as you swap back to factory parts.

Virtually everything in the rear suspension is going to be trash after 80k.

Mine lasted well over doubl that. Highway miles cause very little wear on suspension parts so there is no direct correlation between end of life and odometer.

Every year or so it's good to take the pressure off the springs and push all the ball joints around to see what is worn. You can't tell when the spring is pre loading the joints.

+1^

On 4.6 and 4.8is applications the torque of wide open throttle will wear out rear suspension parts at a higher rate than any 3.0 application. Uppers are long gone at 80-K. Ball joints might as well get replaced as they are simple and removes any worries. Look for any premature wear on the lower suspension arm inner bushings coming from owner/road abuse. Making a big fat BMW handle comes at a cost of replacement parts.

Take a ruler and confirm that your rear subframe is centered.

Replace everything suspect and you will have lots of driving enjoyment.

Very valid point on the bigger motor and like I said largely based on how many highway miles. WOT wear is 1000s of times harsher than expansion joints and curves.

I've never encountered an E53 with over 100k on it that didn't need close to a 100% suspension rebuild. IMO, the bushings and balljoints were very much underspecced for the job.

Both of ours were very gently driven before we bought them.

Fronts lasted about 140-150 rears lasted about 160-180.

My experience is that in typical use, the tension strut bushings in the front end are good for more like 30-50k.

That was the first to fail on both or cars. Both made It over 130,000.


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Good driving habits make for long lasting cars/SAVs. Poor habits = lots of parts!

On my own 4.8is front struts replaced at 40K, Upper arms in the rear gone at 64K.

The same drivers got a heck of a lot more life out of suspension parts on other vehicles. Including other BMWs. The E53's suspension is just not very durable.

They made some of the parts tougher vs. the 5 series it's based on but the bushings; not so much.


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Same applies to E70.



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Fragile is the term I use on our E53's

All BMW's needs a complete front suspension by 100,000 miles. I just did my Dad's F10 5er though and the whole front end was shot by 80,000 miles. Struts wouldn't even rebound.

I find the rears last longer... but +100,000 miles it's good practice to do all suspension related components if you want to experience the way the vehicle is supposed to feel. BMWs are hard on suspensions... is what it is, and why they drive the way they do. You can upgrade to poly bushings or other aftermarket solutions if you want more longevity and are willing to give up a small amount of compliance.

Actually that's a hugely valid point. Worn out to the point of shedding tires and worn out to just not handle like it should are two very different things. I'll be doing some related testing soon and maybe proactive upgrades will be coming.

* my experience with poly bushings has been that the lifespan is usually less than rubber. Also, if they are installed in a pivot point, they require regular regreasing. I mostly recommend sticking to rubber with limited exceptions.

With all the weight e53 have the suspension parts take a beating. How long can you dive on worn out parts? Forever. I had a drop off of a 200K mile one. Everything was original except tires and brake pads.

You can't drive very long on worn wishbone joint! My rear tires wore through the steel belts in two weeks!

^ Not good!

It was trash a *long* time before it got to that point, though. :)

Oh yeah it was. But with tension on the joints from the spring and alignment in spec and no weird wear it can go unnoticed very long.

I'll be taking a closer look at all the joints on our E70s not waiting for obvious failure before refresh.

The thing is that getting to a point where you can actually inspect means doing a large fraction of the work of just replacing them.

I have two relatively to me new e70s. we spent more than our actual budget on the cars and we don’t have extra to immediately replace suspension. had to replace the tires on one of them.

So when I left the car up take all the tires off to do and underside inspection I can get the compression off the springs and check for loose joints

Don't say that, Nick!

I just received these today:

https://i.imgur.com/A8goPuj.png

They're going on my 43k mile, 04 4.4i.

I got them on clearance for $90 + $10 shipping from Modern Automotive Performance. Last set. Manufacture stamp is September 2018. Sorry about the NZ$600 where you are, that I saw in another thread, Wayne, if you're reading this!

I was told by the owner of the best indy BMW mechanic shop in our city that I needed the bushings replaced about two years ago. We did a road test together and he said he could notice them beginning to fail.

Unfortunately, in 2021, in his early 40's, he died of Covid. My retired mechanic friend, who is 72, is going to help me put on the Nolathanes. I have the special extractor tool.

All I'm gonna say is ya got a great deal! ;)