# Rear M5 Swaybar Kicks As$



## DSPTurtle (Oct 4, 2003)

Whoever said the M5 rear swaybar change is subtle... was totally high! 
I cannot believe the difference 1.5mm can make!!! I went through a short set of twisties under acceleration like never before. I will have to do that same set again cause the setup was brand new to me so I was not sure just how hard I could push it... but I was pushing it pretty hard. I can't wait to do the front M5 sway hopefully next weekend. Then I will probably want the Dinan rear sway... but next to come is the HR/Bilstein setup.
Anyway, the new bar is awesome!!!
BTW, I am currently using the 15mm rubber bushings, the new ones should be in by the weekend.
Anyone want a 15mm rear sway bar???
JB
PS...Thanks to the board for posting so much info on this ultra-cheap mod.


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## DSPTurtle (Oct 4, 2003)

I love replying to myself (what a dork)!!!
Anyway, totally unexpected enhancement is stright line stability!!! I cannot believe how much more stable the car is at high speed. A brand new vette with "427" on the hood was next to me on my way home... we got up to 110mph... that is the fastest I have taken my car. Previoulsy the car started to float a little at about 100mph but now it just hugs the road!
I can't wait to do the M5 front!!! I wonder if it will help even more???
JB


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## DZeckhausen (Mar 11, 2003)

DSPTurtle said:


> I love replying to myself (what a dork)!!!
> Anyway, totally unexpected enhancement is stright line stability!!! I cannot believe how much more stable the car is at high speed. A brand new vette with "427" on the hood was next to me on my way home... we got up to 110mph... that is the fastest I have taken my car. Previoulsy the car started to float a little at about 100mph but now it just hugs the road!
> I can't wait to do the M5 front!!! I wonder if it will help even more???
> JB


The M5 front bar makes a bigger difference than the rear. Can't wait to hear your review.

I did my third M5 front swaybar install this weekend, following my own instructions for the first time. I made a couple of tweaks to it, correcting a fastener size and mentioning some model year varience on a bolt position. But otherwise, the instructions were spot on. http://www.zeckhausen.com/howto/bmwe39/swaybar_replacement.htm


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## DSPTurtle (Oct 4, 2003)

Quick Questions
1. Do you need to get an alignment after the sway bar install since so many parts are removed?
2. Is there any advantage to changing the springs/struts at the same time as the sway bar? Are there common items that need to be removed making this more efficient?
Thanks
JB


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## DZeckhausen (Mar 11, 2003)

DSPTurtle said:


> Quick Questions
> 1. Do you need to get an alignment after the sway bar install since so many parts are removed?
> 2. Is there any advantage to changing the springs/struts at the same time as the sway bar? Are there common items that need to be removed making this more efficient?
> Thanks
> JB


No alignment required after front swaybar swap, since everything bolts solidly back into original position. You are not removing any adjustable parts. If you change the shocks, you will need to get an alignment, since the shocks are not symetrical. The odds are pretty good that your new shocks will not be positioned exactly like the old ones. And, if you change your springs to anything lower, then you need an alignment because the geometry is changed.

There's very little overlapping labor for the front swaybar swap and the front springs/shocks. You will take the wheels off and disconnect the swaybar end links and wishbone for both jobs. But that's it.

A more synergistic pair of swaps is changing your front wheelbearings at the same time as you change the springs/shocks. There's almost 100 percent overlapping labor there.


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## DSPTurtle (Oct 4, 2003)

Is it worth changing the wheel bearings even if they are not showing signs of needing replacement? Car has about 85,000 miles.
Is the M5 upgrade worthwhile so that I only have to do this once?
Thanks
JB


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## DZeckhausen (Mar 11, 2003)

DSPTurtle said:


> Is it worth changing the wheel bearings even if they are not showing signs of needing replacement? Car has about 85,000 miles.
> Is the M5 upgrade worthwhile so that I only have to do this once?
> Thanks
> JB


If it was my car and I was going to change the shocks and springs, I would drop in a new set of bearings at the same time. It's only four bolts that have to be removed to get the old bearings out and they are right there in front of you when the strut is removed. No reason to take everything apart twice. And, with 85,000 miles, you are right in the range of needing new bearings anyway. I see them go bad anywhere from 60,000 miles to 130,000 miles with most of my customers replacing them (due to symptoms) in the 90,000 mile range.

The M5 wheel bearings are not an upgrade. They are simply different. They have three dowel pins that mate with matching holes in the M5 rotors. Unless you've upgraded to M5 brakes, you will either have to drill holes in your rotor hats to mate with the dowel pins or you will need to use a grinder to remove the pins from th M5 bearings. I've seen no evidence that the M5 bearings are any beefier or last any longer than the "ordinary" E39 bearings. And at twice the price, the M5 bearings are not cheap.


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## waapples (Jan 5, 2004)

hey guys,

i just have a question regarding to the sway bar upgrade on e39 (528i) BMW.

i'm from japanese import scene and i used to have accord which is FWD. i felt the biggest improvement on handling & at the starting line after i upgraded the rear anti-sway bar to 22mm thick, leaving the front one as factory one. because the aftermarket front anti-sway bar for accord has the same size as the factory ones. it was the best improvement on handling w/o spending too much money. 


however, since i'm dealing with RWD now, i don't know what are the right things to do.

which anti-sway bar, front or rear, plays the critical role on RWD vehicles?
of course it's always better to upgrade the both front & rear anti-sway bars but just to get me started, which anti-sway bar gives the best result over all?

please advise.
i might go for oem M5 anti-sway bar or aftermarket ones.

thanks!


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## DSPTurtle (Oct 4, 2003)

Damnit Zeck... now I will hav eto find a place that can get them to me by Friday!!!
JB


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## DZeckhausen (Mar 11, 2003)

waapples said:


> i'm from japanese import scene and i used to have accord with was FWD. i felt the biggest improvement on handling & start on the line after i upgraded the rear anti-sway bar to 22mm thick & just left the front one as factory one. because the aftermarket front anti-sway bar for accord has the same size as the factory ones.
> 
> however, since i'm dealing with RWD, i don't know what are the right things to do.
> 
> ...


It doesn't matter if your car is front or rear wheel drive. What matters is the balance of your system right now. If the car is heavily biased toward understeer, then you want to install a beefier rear swaybar as one method for reducing that understeer.

If you are going to buy a complete front/rear swaybar set from an aftermarket vendor, you will probably find that they increased the stiffness of the front bar by a small to medium amount and they increased the stiffness of the rear bar by a lot more.

If you are looking for dramatic reductions in body roll as well as a more neutral handling car (meaning less understeer than stock) then you want to buy a matched set of bars from someone like Dinan or Eibach. If you are satisfied with less dramatic roll reduction, but still want a more neutral set-up and you are on a budget, the installation of a rear M5 swaybar is the best bang-for-the-buck upgrade.


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## DZeckhausen (Mar 11, 2003)

DSPTurtle said:


> Damnit Zeck... now I will hav eto find a place that can get them to me by Friday!!!
> JB


I have two sets of them in stock.


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## fixdaserver (Oct 19, 2003)

*Where did you buy the rear swaybar?*

JB, 
Where did you but the rear swaybar and how much did you pay?  
Steve



DSPTurtle said:


> Whoever said the M5 rear swaybar change is subtle... was totally high!
> I cannot believe the difference 1.5mm can make!!! I went through a short set of twisties under acceleration like never before. I will have to do that same set again cause the setup was brand new to me so I was not sure just how hard I could push it... but I was pushing it pretty hard. I can't wait to do the front M5 sway hopefully next weekend. Then I will probably want the Dinan rear sway... but next to come is the HR/Bilstein setup.
> Anyway, the new bar is awesome!!!
> BTW, I am currently using the 15mm rubber bushings, the new ones should be in by the weekend.
> ...


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## DZeckhausen (Mar 11, 2003)

fixdaserver said:


> JB,
> Where did you but the rear swaybar and how much did you pay?
> Steve


Pacific BMW sells them for $93.18 each. The bushings are $3.48 each (2 required). Cutter Motors probably has good pricing on these too. Part numbers are on my web site: http://www.zeckhausen.com/howto/bmwe39/swaybar_replacement.htm


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## sb540 (Jan 25, 2002)

DZeckhausen said:


> Cutter Motors probably has good pricing on these too.


Although Cutter has many fine qualities, my experience has been that their parts prices are not competitive with Pacific, even if you check Pacific first and ask them to match the price. If they have changed their policy in the past few months, let me know, but I bet you will do much better at Pacific (my favorite) or Crevier (preferred by those who say Pacific has bad service).

On the merits of the issue, I also think the M5 rear bar kicks arse. I got mine from Pacific for the price Dave Z quotes, plus CA sales tax and modest shipping. They even had one in stock.


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## DSPTurtle (Oct 4, 2003)

Sadly, the M5 rear bar was purchased locally for a lot of $ (my wife got it for me as a BDay present and does not participate in the online Bimmer madness). However, the front bar and all of the bushings were bought from Pacific for extremely reasonable prices. As soon as I mentioned DaveZ's website the guy perked up and started being extremely helpful.


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