Suspension Install Best Practices

[Bimmer-Bob]

I recently picked up a set of coilovers at a good price, and for different reasons I'm thinking about tackling the install myself. For one, it'll save me some money, and there aren't any shops in my area (southern Spain) that I really trust. The local BMW dealer would likely charge an arm and a leg, and may not want to even touch aftermarket parts to begin with. Plus, I just want the satisfaction of doing it myself.

I will be doing an M3 front ARB first, and then waiting a few weeks before tackling the coilovers as I need to wait for a few more parts to come in. If the M3 bar is difficult (I don't think it will be) I'll know better than to try and do the coilovers on my own. I should also have a copy of BMW's TIS before I touch the suspension, so that should help, too.

I guess my question is this - how difficult a job is this? I've looked over a ton of DIYs throughout the internet and, while it looks challenging, it doesn't look "hard," per se. Some sites say it can be done in as little as 3-4 hours, although for 1ers most people seem to think more like 6-8. I plan on devoting a long weekend to the project (4 days) so that I have plenty of wiggle room for mistakes.

What I'm asking from all of you is any tips or tricks that you learned along the way during your own installs. Sort of the things you wish you knew then that you know now. For example, I understand that the fronts can be a bitch to swing out from under the fender, and that I should protect the fender with painter's tape.

One final question - the consensus seems to be that the difficulty of this job is due more to physical exertion rather than technical complexity. Would buying or borrowing an impact wrench significantly affect the difficulty or lengtht of the project, in your opinion? Thanks in advance.

[Yvette]

It definitely worth it to try....

some tips I can give to you,
1. get a friend to help you.
2. mark the washer when taking off the control arm in the rear.
3. dont rush when tightening any screws/bolts, don't strip them.
4. go over the diy guide and over and over BEFORE start.
5. ENJOY THE DIY, think it as an opportunity knowing your car better

[Squidbilly]

What e90sexion said...plus take your time. I did the front one day, the rear the next, and the front m3 control arms the following day. It's good to be fresh, focused, and unrushed when you work on the car to avoid potential mistakes...just my $0.02.

[Eric@e2design]

leverage.. get some GOOD jacks dont even think about using the one that came with the car.. this is a little complex for a novice but just remember you're simply removing and replacing nothing hard.. good trick is to use an egg carton and put the nuts/bolts in the carton in the order you take it off.. this way you basically put everything back together in reverse order..

plan a break after doing the fronts / backs.. or even sleep it off..

do NOT use powertools if you dont know what you can and cant do.. last thing u want is to strip or break a bolt.. leverage leverage.. if you cant get it off ur doing it wrong =)

oh and dont get oil on your brake disc (dont grab it for balance with ur dirty hands) =P doesnt really matter but yah haha

friends a good idea too

[Eric@e2design]

oh get two jacks.. and take off the wheels to both fronts so u can see what the assembled side looks like =P..

wheel chocks.. or block of wood..

hmm yah.. torque ur wheel bolts..

good luck



just reread your post.. impact.. yes and no.. yes if u know what you can use it on/how you can use it.. no if you dont.. remember leverage.. the onlything hard would probably be taking off the strut -> lower control arm you'll need to line up the hole.. and if ur stuck.. step back and think before u take out that impact you're probably stuck for a reason

[ianc]

2. mark the washer when taking off the control arm in the rear.

DON'T take off the innner bolt. Remove the outer one and you won't upset your alignment setting...

ianc

[Xaeryan]

Originally Posted by ianc

DON'T take off the innner bolt. Remove the outer one and you won't upset your alignment setting...

What he said.

Also, tape off the front fenders using some painters tape so you don't accidentally make a mess of them, whether with tools, the front strut, your hands, etc. I learned this the hard way.

[nordique14]

If you are doing the front M3 arms, you will need an alignment. After you do the suspension install you will need another alignment. You might want to wait to do all at the same time. Then you only pay for the alignment once.

[timhatimay]

I agree with those that said take off the outer bolt on the rear, and this will keep your rear alignment pretty close. Use a wheel pin to help grab and position the rear rotor, so you can insert the bolt that attached the hub to the camber arm. The painters tape on the front fender is also a big help! Wash your car the day before so you don't scratch it with the tape and you leaning against it.

1. I think you will need some sort of impact wrench with thin walled sockets to remove the top bolt from the strut if you intend to reuse the stock top-hat.

2. Remove all the wires, electronics, and plastic headlight level rod BEFORE removing the bolts.

3. Use a chisel in the rear of shock to help pull out the shock, but don't go crazy. You can use your arms to push on the top of the strut when its in the fender well and force it down to clear the fender. I've heard of others standing on the hub and lots of other things, but just lowering it as much as possible and pushing down worked for me.

4. Read the DIYs a ton, and maybe even take a computer or printout with you, as you will definitely need to refer back.

5. Remember the order of the strut top components, and the rear shock mounts. If you are going to re-use these, there are several pieces and it can be confusing at first what order they go on.

6. Keep the spring compressors on very tight (spring very compressed), when you remove the top bolt from the strut. Otherwise the spring will force off the components and fly off and can do serious damage. The springs can very dangerous if not treated with respect.

7. Keep an extra car on hand (and a friend too!), so you can run to the store to buy any tools or extras that you forget about. Unless your garage is stacked, you will probably find halfway through you are missing a socket or wrench.

8. Have at least two good jacks on hand. If thats not possible, then you must have a minimum of one good jack. The second jack is very helpful however in a few instances. Don't forget about a jackpad adapter for under the car! Otherwise your jack might mess up the plastic pads.

Its not that difficult of a job. Somethings are just tedious, but if you take your time and follow the guides, you should be fine. If you find the sway bar difficult, then don't even attempt the suspension. It is rewarding to do it yourself, and this is a pretty fun job. Just take your time!

Tim

[ianc]

Tim gives good advice.

In addition to the painter's tape on the fender, wrap the top of the strut in a shop towel before attempting to get it out from under to further protect the paint.

Most people typically have the greatest difficulty with this job when attempting to get the strut out from under the fender. I struggled, gasped, cursed and sweated with it.
If you intend to the do the M3 control arms at the same time, you can potentially avoid that whole business by just completely detaching the hub from the car. You'll need to unbolt the caliper, etc. More fasteners to undo, but it could be easier and faster because you can just drop it straight down and you won't have to wrestle with it.

Take lots of pictures as you go and before you start to aid in reassembly. Take note of the way the front swaybar is installed, because it is possible to install it upside down. Ask me how I know...

TIS should have torque specs for you.

If you intend to do the M3 control arms, the nuts\bolts need to be tightened in the 'normal' position, which means you need to jack up the bottom of the hub to put some load on it to approximate the normal loaded position it will be in before you torque it.

As you surmise, the job is not rocket science, but if you're much north of 40, it could potentially take a physical toll on you...

ianc

[Kaynucke92]

Originally Posted by ianc

DON'T take off the innner bolt. Remove the outer one and you won't upset your alignment setting...

ianc

I know it has to do with the allignment setting..
but what do you mean remove the outer one....and no inner bolt?
can you explain this with pictures??

[larryn]

Originally Posted by ianc

DON'T take off the innner bolt. Remove the outer one and you won't upset your alignment setting...

ianc

I'm the one who did the DIY, and I also agree. When I did the DIY on my e90, the outer bolt would not come out, so I did the inner bolt. However, you are going to need an alignment, regardless, with these modifications.

I found you are missing at least one major thing on your project plan. Be well stocked with quality beer. I always make it so it's fun, and not a chore, when working on my car. Whether it's with hanging with friends while working, or beering, or both.

It's not too difficult to do, just take your time, and be careful.

[Bimmer-Bob]

Wow - really happy with the response on this thread. Thanks for all the good advice, guys. I'll have to re-read this a few times to make sure I get it all. I'm glad because many of these issues are things that have either occurred to me in passing or that I have alreay addressed (or have read about in other threads), so I don't think I'm wildly out of my element or anything. However, many of these tips are new to me and it's great to have all this knowledge in one place. So, thanks again.

Unfortunately, it'll probably be on the order of several weeks before I tackle this project, as I want to make sure I've got the time off, as well as gather some odds and ends. Plus, I'm debating whether or not I should just go ahead and do the front control arms while I'm in there. In any case, I'll be doing the M3 bar pretty soon, and I think that will be a good warm up.

[Bimmer-Bob]

Well, I did the M3 front ARB last weekend, and it was a piece of cake, so I feel much better about tackling this. I know it's going to be more difficult and more complicated, but it's become a bit more demystified at least.

Unfortunately, I can't really find any one solid DIY for this. There's more stuff on the E90 boards, but it's basically exactly the same, right? It just seems like different people do things slightly differently and I'm having a hard time determining what's superfluous or not...

For example, I saw one video where a guy undid the bottom of the front struts from the clamshells FIRST, so that when he unbolted the struts from the towers they just dropped right out. Seems way easier than trying to swing the strut out with such limited clearance in the wheel wells. Any thoughts on this? This same guy made the rears look way easy as well. (link: http://www.m3forum.net/m3forum/showthread.php?t=180341)

Anyway, right now I'm just waiting on camber plates and rear shock mounts from Dinan. Ordered them a week ago and I don't think they've even shipped yet...

[Xaeryan]

The rears ARE pretty easy. The problem with the fronts is even with the method you mention, you really need to pull the hub downward to release the strut bottoms - I don't see being able to remove them without unbolting the front control arms from the hub and moving them out of the way (not a big deal). And the strut clamps are TIGHT - we used a pneumatic hammer to remove them by pointing the hammer downward on the top edge of the clamp (be careful!).
I think most mechanics would at least loosen the strut tower bolts a bit so you have some play in the strut, but it is held high to give you room to lower the hub assembly off it. Hope that helps.

[Bimmer-Bob]

Thanks for the input. Speaking of the rears, the DIY I linked to only mentioned 13mm bolts at the shock towers and an 18mm bolt at the lower part of the shock. Some of the other (E90) DIYs mention using 19 & 21mm sockets (on the control arms or camber arms or whatever). Is this necessary? Or can I get away with 18mm and below sockets? (If not, I just need to borrow some larger ones, no biggie - just want to know before I get started).

[Xaeryan]

Originally Posted by Bimmer-Bob

Thanks for the input. Speaking of the rears, the DIY I linked to only mentioned 13mm bolts at the shock towers and an 18mm bolt at the lower part of the shock. Some of the other (E90) DIYs mention using 19 & 21mm sockets (on the control arms or camber arms or whatever). Is this necessary? Or can I get away with 18mm and below sockets? (If not, I just need to borrow some larger ones, no biggie - just want to know before I get started).

This has it correct for the rear disassembly (NO DISASSEMBLE JOHNNY 5!): http://www.oneseriesbmw.com/forums/1...-1-series.html
I don't know what an E12 screwdriver bit is, but I faintly remember two torx bolts holding the shock bottom in, so maybe that's what that is. So you will need a 21mm to drop the arm and allow easy removal of the spring/shock.

[Bimmer-Bob]

Thanks for the link - looks perfect! I've never even seen that forum before.

[Bimmer-Bob]

Apparently E12 is an external torx socket, sort of the reverse image of a torx driver. Anyone have any luck using a traditional metric socket on these bolts, or do I need to order this E12 socket?

[Xaeryan]

Originally Posted by Bimmer-Bob

Apparently E12 is an external torx socket, sort of the reverse image of a torx driver. Anyone have any luck using a traditional metric socket on these bolts, or do I need to order this E12 socket?

That's inline with what I remember. I don't think a metric will work on this, and I wouldn't be brave enough to try without backup bolts. Take a trip to your auto parts store and see what they have in torx bits/sockets, shouldn't cost much for a small set that includes this size. They may even have rentals available, at least in the states they do.

[Bimmer-Bob]

Is the bolt on the stock strut brace also an E12 by chance? It's definitely an external torx type bolt.

It looks easy enough to work around the strut brace on the driver's side, but it looks like it will need to be removed on the passenger side. Did you remove it?

[Xaeryan]

Originally Posted by Bimmer-Bob

Is the bolt on the stock strut brace also an E12 by chance? It's definitely an external torx type bolt.

It looks easy enough to work around the strut brace on the driver's side, but it looks like it will need to be removed on the passenger side. Did you remove it?

No, an open end 13mm wrench can get at them (upper strut mount nuts) without removing the brace, it just takes a bit more time and patience - each side has one nut that is a bit hidden away under the brace, the rest are more easily accessed. But the bolts you see on the brace are the same style as the ones holding the lower shock mount in place on the rear, don't know about the size between them.