Front Axle Support/Suspension advice
Posted by Earendil
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For some time now, I've known that the front of my car needed some work. I knew I had a number of wearing joints, and that it needed some serious TLC. It wasn't until yesterday when I had my tires changed, and the "mechanic" (or perhaps better referred to as a "tire dude") asked me to come outside and show me something, that I realized exactly how bad it was. It is far easier to see how much play this system has when the entire car is up on a lift, and you can really yank the tire back and forth.
So, I am a little bit sketchy on the exact names of these parts, so I'll just use RealOEM links to make sure we're on the same page. And would I be wrong in assuming some of these parts of a couple different names for them? Anyway, on with the show... Rubber joints in the Stabilizer Link (#8) top and bottom are pretty well worn and need replacing. In addition, the two forward points on the Wishbone (#4) are worn. Also, the rear rubber mount (#8) for the wishbone is worn, and has a lot of play. I'd like some general advice, that I promise not to file a suit if you end up being wrong. 1. how "bad" can these get? Do they pose a danger, or do they just end up costing more in the long run if they aren't dealt with now? 2. How easy is this to do myself? I'm aware that general skill, tool set, and time are large factors in that answer. Tools are probably the largest limiting factor, as I'm still trying to build up even the most basic toolbox. A few articles online that seem related, hint that a "puller" and a hydraulic press may be needed for dealing with the Wishbone? 3. What other parts besides the rubber might be worn or need replacing? Do the metal links/wishbone stand up pretty strong, even with degrading rubber, or do these get worn out and damaged as well? I know that one of the first questions is going to be "how much play is there", and if someone tells me where to measure that, I'll tell them. I can start by saying that the wheel had at least an inch of play in it right to left without the steering column moving. But outside of a less than sharp steering response, there is no vibration in the car at all...at least not until you hit 90mph, which I think I can safely attribute to the loose front end system, instead of the old tires that I was blaming it on before 
My immediate reaction to this entire thing is that I'm in well over my head, especially without an easy way of lifting my car. But since I don't have $1000 to throw at a mechanic to fix it, I'm stuck living with it, or fixing it myself. All advice is, as always, greatly appreciated! |
The stabilizer links are also known as sway bar links. you can definitely replace these yourself, and while you are at it, you should replace the sway bar bushings as well, as they are also probably worn out. while it is true that the metal parts are usually pretty durable, i don't think the "forward parts" of the wishbone, aka control arms, are replaceable, because they are built in to the control arm. also, my 318is had a bent control arm that i didn't know about until doing other work, so yes they can be damaged which will throw off your alignment as well. therefore new control arms must be purchased, and new control arm bushings (#8). while it is true that it is a huge pain the press bushings into the bracket (#7), some online parts places (including turnermotorsport, last time i checked) will send you the bushings already pressed into place, so all you have to do is put everything together. it sounds like you might as well get new tie-rods while you are at it, and if you really don't wanna mess with the front of the car for a long time, do the wheel bearings and brakes too. (note: tie-rod removal is made much easier with a tie-rod puller, which i happen to have) you can do all of these things yourself, but you MUST get an alignment after all of this, which you should have someone else do. i dont think you are way in over your head. as long as you have a jack and jackstands, along with a metric socket set and other random tools, you can do it yourself or with a friend. as for your safety concerns, worn out suspension parts lead to imprecision in steering as you know, and can also cause your brand new tires to wear out faster than they normally would. btw, sorry i missed your IM the other day.  Edited 1 time(s). Last edit at 03/22/2009 05:05PM by daniel. |
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Keep it under 90 and you don't have a problem, right?
Those links are easy to replace. I'm not sure about how much trouble the rubber bushings are, but none of those parts should be causing your steering to have play. Those are all parts that add stiffness to the suspension. If the "tire dude" didn't show you loose tie rod ends or worn out ball joints on the control arms or worn out control arm bushings, maybe you don't have steering problems at all, or even more likely, maybe he didn't find what was really the cause of the play. How long did your last set of tires last? Did they have uneven wear? If you think there's a real problem the best move is probably to take the car to a shop that knows BMW's. That probably wasn't all that helpful, but at least I won't be getting sued. 
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Today I went outside and precariously jacked up the front end of my car using a few jacks and blocks of wood, and then slipped my camera underneath to get a few decent pictures.
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And here is my color coded one to make doubly sure I'm naming all the parts correctly :-) 
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New car lingo...check. I'm starting to understand why I was not really solid about the naming of some of these parts
Will need alignment, check. In a perfect world I would also have a good socket set, torque wrench, jack stands, a press, tie-rod puller (if I do those), and a ball joint tool. Is that what I'm hearing is the complete line up so far? Oh yeah, and a set or two of spare knuckle skin
turner doesn't have the pre-pressed bushings+arms. But I'll give a look around the internet. Since I don't have a press and don't intend to purchase one any time soon, paying a bit extra might just be worth my time+gas+paying someone else to do it. Any reason you suggest doing the tie-rods as well? Is it a convenience thing? I know the rubber boot on the wheel side of the tie-rod is split, but does that mean the entire tie-rod is now bad, or is there an intermediate connection that can be replaced instead?
How sure are you that those parts wearing won't cause extra play? I wasn't about to take the guys word for it. He took me out to my car, and when he grabbed the tire and moved it left-right, I immediately dropped down on my side to have a look while he moved the tire. Sure enough, the tie-rod was pretty stiff, but the control arm and sway-bar link were moving around like crazy*.
The Ball Joints in this case are the two forward connecting pieces of the Control Arm? If I were able to get them seated, why exactly would I want to remove them? The bushing+lollipop will have to be dealt with somehow... After taking a second look at my car, those bushings are one of the most (visibly) warn pieces, and really need to go. And thanks for the ebay link Ferdinand. I wouldn't have thought such kits were sold on ebay...
Bilsteins are on the list, but they are on the long-term-after-I-have-a-steady-income list ;-) Right now I'm looking to get my car to a point where if I take a corner hard, I'm not exiting swearing at myself and thanking God my car is still on the road ;-)
Oh how true that! I do want to make clear that I appreciate all your comments, both from the go-getters as well as the more cautious. I'm still trying to get a feel for what this job entails, so I'm sure I'll have a few more questions here before too long :-) Edited 1 time(s). Last edit at 03/23/2009 06:28PM by Earendil. |
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I would think you could probably just replace the tie rod ends, unless your rack boots are cracked as well, then you might just as well do the whole tie rod with boots. The reason I suggested doing the shocks as well is because this is a pretty labor intensive job and you have to do it all again to install the Bilsteins so you are really money and labor ahead if you do it now, not to mention another realignment with the new shocks. The shocks can be tricky too as the nut that holds the shock in the strut needs to be torqued to a very high torque. This is impossible to do with a normal torque wrench and I ended up having to tighten that nut with a pair of channel locks while the strut was mounted on the car in order to get enough force to get a good grip. I have no idea if that nut was torqued to the proper value, but it is still holding so I guess it is sufficient. Enjoy!
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Better go ahead and get the Bilsteins now. The steady income thing is a lot like Santa and the Easter Bunny.
John |
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the pre-pressed-into-lollipop bushings might not be advertised on many sites, but a lot of places will do it. afaik, if the tie rod boot is torn, it means you need to replace the whole tie rod. tie rods arent very expensive. as i mentioned, i have a tie-rod puller you could use. i could just send it to you and you could send it back.
here is the turnermotorsport page. there is a little drop down box where you can select to have the bushings pressed into the carriers. [www.turnermotorsport.com] wow, and i dont know why these all of the sudden dropped significantly in price, but you can also get the offset m3 control arm bushings, which increase caster giving you a quicker turn-in. they are also solid rubber rather than rubber with gaps in it. there isn't much reason to not get these instead of the regular ones. [www.turnermotorsport.com]
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Yes. The end of the control arm in the bottom of this image fits into the rubber control arm bushing. The ball joints are under the rubber boots of the two bolts sticking up. The long bolt in the centre goes up through the engine subframe crossmember. The shorter outer bolt at the left end goes through the bottom of the suspension strut. The ball joint has to be free to rotate with the strut as you turn the steering from side to side, and pivot as the suspension moves up and down. The rubber boots are critical to keep grease in and sand out of the ball joint. If you tear a hole in the boot, the ball joint will soon wear out and die with excessive play. 
The new control arm comes as one assembly with the two ball joints already pressed into it. It's fairly straightforward and simple to bolt the new control arm in place. The bigger problem is getting the old control arm off first. It looks like you just need to undo the nuts off the ends of the ball joint bolts and the whole thing drops off. But it's not that simple. Here's a clearer image of a newer style non-E30 control arm. Look at the long bolt at the top centre of the image. Ball joint bolts are not straight cylindrical bolts. Look closely where the bolt goes down through the rubber boot and you can see that the bolt is tapered. It's cone-shaped. When the nut is tightened it pulls the ball joint bolt tight into a matching cone-shaped seat in the engine subframe crossmember, and similarly into the bottom of the suspension strut. 
When removing the old control arm, you'd undo the nuts holding the ball joints, but the ball joints will refuse to come out of their tapered seats. Pounding on them with a hammer will just destroy the threaded tips of the bolts. It's the same thing with the ball joint at the outer end of the tie-rod links, where they fit into the steering knuckle. You need a ball-joint separator tool, or tie-rod puller looking like one of these. If you're going at this with a pair of vice-grips and a big hammer, you'll make a mess of it. It's much easier when you know what you're doing AND have the proper tools. 
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So, ignoring the CA bushings and associated bracket, I'm seeing Control Arms, Tie rods, and sway bar links from between $290 (BavAuto) and $345 (Turner), with a few of my own favorite supplies actually falling in between, and none of that includes shipping. I'm actually quite surprised that BavAuto is falling on the low end :-)
However, with the ebay kit listed above, I can get all those for $185 and free shipping, which seems like a steal. John, you weren't so happy with the CA bushings off ebay, but the rest of the equipment was decent? If I end up getting the bushings+bracket elsewhere, what would you think? As for the CA Bushings, I need some real opinions. (everything I'll mention is as a set, since I need two of everything) OEM CA Bushings cost $13 M3 CA Bushings cost $40 Or, BavAuto has brackets with pre-pressed OEM bushings for $100, and Turner has the same things for $140 but with the solid offset M3 bushings (thank you sale). So it looks like the whole pre-press thing is going to cost $75-$100, which I can't imagine a machine shop charging the same thing for? Does anyone remember what that cost them, if they went that route? I'm aware I'm getting new brackets and a time saver out of it. I'm just curious what the difference in cost is here. Also, are the M3 solid bushings worth the extra $40? Or am I paying for the bragging rights of saying I have an M3 part on my car?
This entire discussion has been quite enlightening so far. Thanks everyone! |
I would definitely recommend getting the bushing somewhere else. And I also wasn't all that happy to see the tie rod boots cracked after two years. Even though tie rods are cheap, you still have to get an alignment done after you replace them and that's $100 around here. The Control arms were decent, but I had them off too at two years (about 15k miles) so I could replace the CA bushings, and I thought the ball joints in them felt a little loose for such low mileage. I did put them back on the car. Their boots were still in good shape. I chose the M3 bushing when I had to do the job again mostly just because I like all that extra rubber in there. Since the bushing fails because the rubber ages and deteriorates, it just made sense to me to get a bushing with as much rubber as possible in it. I get all my press work done by a guy I worked for twenty+ years ago (damn, where did that time go? :surprised: ). It's an easy job to press the bushings into the bracket. You should be able to get it done for an hour of shop time for the whole job. It was not easy to press the bushing and bracket onto the end of the CA. The M3 bushing was a lot more trouble than the stock bushing, but that might have just been a difference due to the quality of the bushing, not the extra rubber. It might be worth paying for another hour of labor to get the bushing and bracket pressed onto the CA if you don't own a bunch of sockets and a pipe clamp. Maybe if you're lucky you can get the whole mess put together for the hour charge. A shop that knows BMW's can probably do it in that amount of time. You know, it's not that much more money to get those Bilsteins and install them while you're already doing all this work. 
John |
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The Go-Getters vs the Cautious strike again ;-)
I'm certainly no car mechanic, but I grew up with a Dad always willing to learn something new (especially if it meant new tools), and unlike the average sitcom male, he actually succeeded :-) Anyway, I ended up helping build many parts of our house, and have tinkered with many a things. I'm very much willing to live by the "Every tool is a hammer, except for a chisel, that's a screw driver" motto. So When someone tells me I need a hydraulic press, I feel inclined to question exactly how much force I really need. If I go home, I have a whole ton of wrong tools to get just about any job done
If it's a matter of making sure both metal rings stay parallel to each other as force is applied, than that is a good reason not to take a hammer to it. But would taking two small steel plates and a regular press do the trick? How about two blocks of wood and a car jack? It seems like even a car jack should have plenty of force to pull this job off. But then I've never done this before. There is a NAPA not too far away, and if whatever is required is standard NAPA issue, than I should be able to pull this off even as a backup to my own failings. After all, I can buy a couple M3 bushings and brackets for the cost of a pre-assembled bushing/bracket. As for whether I use the M3 bushings or not, that comes down entirely to tire ware I guess. I don't need a little extra snap in the steering wheel at the cost of tread, but there seems to be two opinions on that matter above, and they are in disagreement. I don't want to discourage anyone from giving an opinion that they aren't 100% sure about, otherwise we all wouldn't have a lot to say ;-) But if anyone could back up one or the other opinions above, be it a technical answer or one of experience, that would be great. I'm feeling more and more confident I can get this done myself. I have a buddy who grew up fixing Subarus and Toyotas, and knows how to strip them down and put them back together. However, though he comes with some good mechanical experience, I don't have a lift, and he is 6'5 and 300lbs. So I'll be the one on my back under the car doing most of the work o
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If anything, my tires are doing better with the M3 bushings. After all, my stock bushings were shot most of the time I used them and they were letting my front end vibrate like crazy. You will need a real press to get the bushings in the lollipop. You might get lucky and be able to get them on the CA by hand. If not, maybe you can rig up something like in my picture above. If you have a 300 lb helper you have almost twice as much weight to use pushing the bushings on by hand as I had. That might make all the difference. John |
they increase caster, not camber. big difference.
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the m3 bushings won't increase tire wear. they increase caster, not camber. caster has to do with the angle of the axis around which the wheels pivot. the m3 bushings increase positive caster, which, as i understand it, makes the wheels lean over quicker when turning, hence the snappier turn in. 
i think you can do it yourself too. i am even willing to drive up to help you if we plan ahead. edit: not to spokane, but to white salmon or wherever it is you live. Edited 1 time(s). Last edit at 03/25/2009 11:25PM by daniel. |
you should have seen some of the stuff i suggested back when i was new to all this e30 and mechanic stuff. don't sweat it.
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