Author Topic: Sway Bar Factory Upgrade (Read 6895 times)

max123 · « **on:** May 28, 2010, 06:40:06 PM »

FYI - Just checking out some part numbers and thought this might be interesting to a few members.

Some 318is models came with the uprated 14mm rear sway bars from standard 12mm but its seems fairly random - if you discover you have the 12mm bar and you want to upgrade mucking around - find a junkyard 325ix - all came standard with the 14mm bar.

Also, all 318is and 325i models came with a 20mm front bar. The 325ix bar doesn't work and is a one-off to accommodate the front wheel drive. Best upgrade option is off the convertible - all came standard with a 21mm bar.

New bushings that are size specific are required when swapping out either front or rear.

PumpItUp · « **Reply #1 on:** May 30, 2010, 01:19:22 AM »

thanks for the info! i was confused about the rear situation. on all the parts sites theres 3-4 options for bushings without mention what size came on what model.

finding a junkyard ix doesn't seem very likely

max123 · « **Reply #2 on:** May 31, 2010, 02:07:12 PM »

FYI - Here are the part numbers:

325ix
Rear Sway Bar 14.5mm: 33551129194
Rear Sway Bar Bushing: 33551130349

E30 Convertible
Front Sway Bar 21mm: 31351132337
Front Sway Bar Bushing: 31351132355

Although these sway bars may have been installed on other E30s they were not standard, or were a possible option - and as such if you go to a junk yard or buy sight unseen off a different model you may end up with exactly the same sway bar you already have. I have listed the above models because they were the ONLY option for those vehicles.

Also, the sway bar links are not size specific and are the same on all e30s

I found a rear ix sway bar in about 20 minutes on craigslist and am getting it for $40. At any given time there are always 2-3 being parted out.

tjts1 · « **Reply #3 on:** May 31, 2010, 02:46:42 PM »

I've probably looked under 100 E30s at the JY over the years and a dozen 318is. I've never seen a factory 14mm bar under any of them. All were 12mm.

colin86325 · « **Reply #4 on:** May 31, 2010, 05:59:57 PM »

On the 318is, the 14mm sway bar applies to the Mtechnic package only.

Or get a 14mm rear sway from an E30 M3.

max123 · « **Reply #5 on:** June 01, 2010, 12:30:28 PM »

Like I said, raid old ix junkyard models. The M3 sway bar is the same part# but any part off an M-car is treated like gold by most sellers.

max123 · « **Reply #6 on:** June 14, 2010, 11:59:42 AM »

Success - 2 weeks from idea to reality. I now have a better than stock setup with all factory parts. 21mm in the front 14.5mm in the rear and it is noticeably stiffer. They whole thing cost me $150 including both sway bars plus new factory bushings from BMW.

Here are some notes on the installation.

Installation of the rear bar is difficult and can take a long time just beause it is so fiddly. The bar is unbolted, bushings and links removed (don't bother trying to leave the links on, they get in the way when removing. Go nuts on penetrating lube and everything just goes that much easier (just don't overspray onto your brakes). After that - unbolt the passenger side rear shock absorber and then work the sway bar out the passenger side wheel well. It will come out without the diff needing to be dropped.

Assembly is the same in reverse - don't put the links on beforehand. Despite suggestions to use dish soap to get the links back on, I couldn't make it work. Use a thin pentrating lube and then wash it off with some citrus engine cleaner and lots of water later.

The front sway bar comes out much easier than the rear. All you do is unbolt the sway bar connections and then unbolt one of the control arm lolipops - the sway bar will slide right out the back. One main note on the installation. Triple check the direction of the new bushings before installation. They are directional and have arrows - also, BMW seems to have changed or updated the stock sway bar bushing. Previous they had a single cute down the middle which made them easy to get on/off. The new 21mm bushings were not cut and have to be worked onto the sway bay with some grease (its a bit of a pain, especially if you put them on backwards).

Lastly, the factory metal mounts are a bad design utilizing a sort of latch and bolt connection. I have taken them off a few times and reassembly has always been fiddly - so budget an extra 15-20 minutes of swearing and messing around on each side. Also, maybe invest in a new set of mount bolts - one of mine snapped on reinstall. Just remember - don't use hardware store stainless - they have no strength and will fail - ask for the high strength bolts or better yet go to BMW. It may cost you 3-4 bucks for 2 bolts and 2 nuts - but who wants their sway bar to fall off on a hard corner.

Jorgeconrico · « **Reply #7 on:** June 14, 2010, 09:08:41 PM »

Should have thought about new sways before I had rear sway links put on. They will be a bitch to get off.

This is a good option, but where I live we have no decent junk yards. I like having original parts, especially ones that improve handling.

max123 · « **Reply #8 on:** June 17, 2010, 11:48:41 AM »

I don't want to overstate the effects - it is only a modest upgrade with factory parts - but I have really noticed the difference. It has tightened up the front and back end and keeps the nose and wheels planted while reducing the typical body roll.