Front End - Piss me off

[Scott C]

Well,

I am now putting new bushings in the upper arms, got 20K out of the 750 (Green) bushings, at least the balljoints are okay this time (Lemforder!). For those contemplating replacing their front end parts, take heed.

I have to admit, I do drive this "gently" although there is the occasional pothole. I just hate this design.

By the way, the symptom was accelerated tire wear on inside and out.

Scott

[Scott C]

I actually run my front tires at close to 40PSI, they were at 32 psi when the rounding occurred and these are new tires with less than 5K miles.

I went with the M5 bushings although I was tempted to try the Poly Grunt bushing that Jon K uses.

[mikell]

Better to be pissed off than to be pissed on.

[e34.535i.sport]

It is a poor set up i'll give you that - when one thing goes they aqll seem to go! Those control arm bushings are sh*te. I haven't had any uneven tire wear luckily though as my tires are pretty new! I assume you made sure they were at the correct PSI?!

[Jehu]

I've had M5 Bushings in for about 40K miles and as far as I know they're still fine. had the car to BMW Indy last week who did motor and tranny mounts ,looked at everything else and didn't mention the control arm bushings. No bad wearing i can see. Try the E34 M5 bushing (http://www.autopartswarehouse.com/search/?N=9773+1580+4294966982+9198)...

[Scott C]

If the 750is are fluid filled the M5's are not. If the concern with most about Urethane is the hard impact or lack of impact absorbtion I can't imagine them being much harder than the M5s so if they last far longer I may try them next time.

Thanks for the link by the way - I had already ordered (from the same place) when I noticed you posted a link!

I was worried about accelerating wear on the rest of the components if the bushing was too stiff. While I don't drive harshly, we have the mother of all potholes up here as a result of the winter and that does takes its toll on the suspension.

Scott

[Jehu]

I actually run my front tires at close to 40PSI, they were at 32 psi when the rounding occurred and these are new tires with less than 5K miles.

I went with the M5 bushings although I was tempted to try the Poly Grunt bushing that Jon K uses.

If the 750is are fluid filled the M5's are not. If the concern with most about Urethane is the hard impact or lack of impact absorbtion I can't imagine them being much harder than the M5s so if they last far longer I may try them next time.

[Scott C]

Finally took time to do front end this week end. This is what I found - the Lemforder 750 bushings (and arms) actually are not damaged visibly in any way and still feel tight.

The symptom I am trying to fix is excessive wear on outer edges of front tires and maybe I presumed too much about the contribution of these bushings. I am going to put the M5 bushings in (this will be fun) anyway although I am surprised at the amount of open space in them (compared to 750).

Idler arm seems fine, tie rod ends still tight and ball joints have no perceptible slop.

Any thoughts?

Thanks,
Scott

[Scott C]

Wow that time is pretty goofy

[xspeedy]

I'm not very experienced, but maybe too much toe? If your upper bushes are bad, you should see a lot of wobble under braking.

[Sam-Son]

Polyurethane Bushes here
My philosophy is anytime anything needs replacing it gets replaced with a performance part:D

[Scott C]

Wheel Alignment or wheel balancing? Can be thrown out with potholes, both are cheap to eliminate as the cause so maybe worth a shot.

Wheel alignment is spot on and these are new tires that wore evenly on both inside and outside, almost like there was not enough pressure in the tire.

Put the new bushings (M5) in today, what a hassle, I will never do that again. 12 Ton press was really working to get them out (they were 2.5 years old).

I will run the fronts at 40psi to even out the wear...

[leicesterboy15]

Wheel Alignment or wheel balancing? Can be thrown out with potholes, both are cheap to eliminate as the cause so maybe worth a shot.

[Tiger]

If you are only wearing on the outside now, your toe spec is not spot on. Too much toe in will wear out the outside of the tire. As for the steering check, jack up one side of the car, see if you can push in or out the wheel by turning the tire, any movement means worn steering component... which would create that inside and outside wearout.

[leicesterboy15]

I replaced my whole front end at the expense of many knuckles and much aggro, then when I got it all back together and got the car 4-wheel laser aligned (twice!) I still had a shimmy, then I got the wheels balanced and it went away, I couldn't believe that a small weight could make such a difference, and my wheels don't have a single kerb mark on them so they were not damaged but still needed balancing slightly. Over here its only about £5 per wheel so it might be worth eliminating as well? I know how frustrating this problem can be, I went 2 months without being able to go over 50MPH, imagine that :)

[healtoeit]

It is a poor set up i'll give you that
How is it bad? I just don't understand! please explain

[Scott C]

If you are only wearing on the outside now, your toe spec is not spot on. Too much toe in will wear out the outside of the tire. As for the steering check, jack up one side of the car, see if you can push in or out the wheel by turning the tire, any movement means worn steering component... which would create that inside and outside wearout.

Tires are evenly wearing (but way too much on the edges in my opinion) on both inside and outside on the front. Only motion I saw was due to son's inability to hold the steering wheel tight enough while I pushed on the wheels - it seemed tight and the old bushings were good (fluid was still intact until I pressed them out)

[Tiger]

You don't need anyone to hold steering wheel... one side of the front wheel is on the ground. Any in and out movement by wiggling means worn steering components...

There are alot of instances where the steering tie rod or the drag link or the idler arm was slightly bent out of shape... not visible to eyes... that end up causing very wierd tire wear because of extreme angle when turning.... a simple smack on the curb will do this.

[ProZak]

... Only motion I saw was due to son's inability to hold the steering wheel tight enough while I pushed on the wheels ...

Try it again with steering locked instead of a helper holding, might be a better test.

[Scott C]

Actually, I did check with one wheel on the ground - there was no motion relative to each other that I could detect but I did notice that both wheels moved when I wiggled the one in the air. Now I may have some backlash in the steering box (but it drives fine) but I would not expect that to cause the tire wear issue just sloppy steering control, which I don't seem to have.

[e34.535i.sport]

How is it bad? I just don't understand! please explain

Just meant in terms of the rapidity of failure on parts... And if one thing isn't at its best your looking at the rest going with it too!

[healtoeit]

Just meant in terms of the rapidity of failure on parts...


This is due to the weight of our cars, not the bad design of the suspension.


And if one thing isn't at its best your looking at the rest going with it too!

Thats only the case if you leave one of the parts broken for some time and the others take more stress due to the other parts failure.

The MacPherson strut is a great design that most owners take for granted. I mean, BMW is still useing it (granted it has been modified)!

Try driving a car with a kingpin! Those parts wear much faster then ours, on cars that are lighter too.

[Scott C]

Well after putting in the M5 bushings and driving a little over the last few months, finally got a chance to look closer. Looks like the pass side front arm has a ball joint that is just a little sloppy - these are lemforders and in my humble opinion I still think this front end is terribly weak - there is about 1/16" of slop roughly at the edge of the wheel. This is now 2 sets of front end components in 60K miles. Yes, the roads are crap around here.

For what it is worth - the Meyle lasted 25K miles, the lemforder lasted 30K (yes I have detailed logs ;) ). The Meyle failed to due boot decomposition and grease loss.

Scott

[Tiger]

Scott... this is an old thread... still you have to consider the impacts of other front end ball joints on the thrust arm... If the lower cotnrol arm ball joint is shot. it will wear out the upper control arm ball joint.

I just had my wheel aligned after changing out complete steering... the mechanic said my right lower ball joint is gone. I let him change it out and saw how bad it was. I realized another clunk as I was driving to him.

Now, my entire front end is changed except the driver lower control arm... He said is fine.

Loose steering will cause accelerated thrust arm ball joint too. Along with lower control arm... and the sway bar linke! Seriously speaking! Think about it. If the factory suspension lasted to 80,000 miles... why can't the new parts last just as long? Because it is all new to begin with.

[Scott C]

All moving front end parts were new when I did this job! thrust and control arms, sway bar links, Shocks (cant remember brand), did NOT do shock mounts, idler arm - I mass replaced everything as I wanted this to be safe and drive as close to "new" as possible. I did not replace front wheel bearings.

Ah, done complaining for now :) did get the drivers heated seat repaired (75$ of ebay), so now prepared for the cold - of course it is 90F here today.




Scott... this is an old thread... still you have to consider the impacts of other front end ball joints on the thrust arm... If the lower cotnrol arm ball joint is shot. it will wear out the upper control arm ball joint.

I just had my wheel aligned after changing out complete steering... the mechanic said my right lower ball joint is gone. I let him change it out and saw how bad it was. I realized another clunk as I was driving to him.

Now, my entire front end is changed except the driver lower control arm... He said is fine.

Loose steering will cause accelerated thrust arm ball joint too. Along with lower control arm... and the sway bar linke! Seriously speaking! Think about it. If the factory suspension lasted to 80,000 miles... why can't the new parts last just as long? Because it is all new to begin with.

[Paul in NZ]

All moving front end parts were new when I did this job! thrust and control arms, sway bar links, Shocks (cant remember brand), did NOT do shock mounts, idler arm - I mass replaced everything as I wanted this to be safe and drive as close to "new" as possible. I did not replace front wheel bearings.

Ah, done complaining for now :) did get the drivers heated seat repaired (75$ of ebay), so now prepared for the cold - of course it is 90F here today.

fwiw i regard OUTSIDE front tyre wear as normal....my car has "sport suspension setting" and i think this means a bit more toe.Translates to excellent turn in and feel(for a 1600kg 4 door sedan),and slightly vauge on centre.I do however run my front tyres at 39psi,and as soon as the front starts to exhibit outside wear i swap em to the back ON THE SAME SIDE.
I have had my car for about 6 years and have done 100 000 km.In that time i have had ONE new pair of arms and 750 bushes.Wheel alignment and balance is critical though,otherwise you will have the shimmy(17 in 8.5 wheels and 235 45 tyres).The back tyres also wear the INSIDES more than the outsides,and for that reason never swap front to back and side to side otherwise you wear the same side again,and will have that edge well worn while the rest of the trye is fine(well still ok wear wise).I have had one complete new set of tyres,1 partially worn set of tyres,and have just put two new ones on the front.All front tyres exhibit the same wear pattern.If you are wearing both sides i think that is a sign of under inflation

[Scott C]

All right - here it goes (I know Tiger, this is old, but it gives closure ;) )

After putting new components in on the side I thought was bad, the majority of the problem was due the steering sector adjustment. Now fixed so that 55mph vibration is gone (and $250 poorer - oh well). I did note that there is no adjustment left in the box and I did have to back off a little more than i wanted to as there was a little binding that was noticeable while driving. Anyway, I take back all I said about thrust & control arms failing so quickly. Truth be told, I suspect that 2/3 of my front end vibration was due to the steering box adjustment and if I had been more thorough in the first place.........

Scott

[Tiger]

Gee.. Scott... even with your final post today... I still don't know what you changed to fix the problem.

[Scott C]

Gee.. Scott... even with your final post today... I still don't know what you changed to fix the problem.

Steering box backlash....

http://www.bmwe34.net/Wiki/tiki-index.php?page=Steering+play

[bsell]

This is due to the weight of our cars, not the bad design of the suspension.

This is like saying, "the building design was solid, but the roof fell in because it was too heavy."

A properly engineered system does not fail when used for its intended purpose.

BMW makes much of their cars being 'the ultimate driving machine,' so they should stand up to being 'driven.'

I can't think of another car series that requires such frequent suspension parts replacements as the E34. Hence the engineering on the front suspension was marginal at best.

Am I wrong to expect 100K miles out of the suspension parts? Many, many car models do this with ease, but not the E34s (nor the 3 series of the same vintage).

Brian

[Scott C]

This is like saying, "the building design was solid, but the roof fell in because it was too heavy."

A properly engineered system does not fail when used for its intended purpose.

BMW makes much of their cars being 'the ultimate driving machine,' so they should stand up to being 'driven.'

I can't think of another car series that requires such frequent suspension parts replacements as the E34. Hence the engineering on the front suspension was marginal at best.

Am I wrong to expect 100K miles out of the suspension parts? Many, many car models do this with ease, but not the E34s (nor the 3 series of the same vintage).

Brian

Actually, 1 Think 100K (well maybe 80K on original, and 50-80K after first set of replacements) is possible and can be expected. However, In my case, I should have been more thorough and checked everything when putting my first set of thrust/control arms in... In other words, the inspection I did this time - where I individually validated each component - the tie rods, center/drag link and pitman arm units as well as backlash in the steering box (sector adjustment).

In the past I had replaced the thrust/control arms, tie rods, sway bar links and replaced the shocks/shock mounts and that made it drive fine until tolerances/wear built up enough for the vibration to occur again. But if I had checked further and more thoroughly the FIRST time, I would have found that some amount of looseness in the front end was due to the steering box backlash (sector adjustment) and IF I had done the steering box adjustment the first time, I would not be playing with my front end at this point in time.

Just my perspective - I admit the errors of my ways and I do sometimes order/slap parts on to get the thing running :)

Scott