Tuesday, October 4, 2016

The Ultimate BMW E46 Suspension Refresh Guide with Complete Parts List

BMW E46 Suspension Guide
by E46Mango

This guide will provide essential information to refresh your non-M E46 suspension.

I realize a lot of people are on budgets so I'll divide this list into three stages in order of most important (failure prone) to least important (more durable). Start with Stage 1 and work your way up to Stage 3.

Stage 1: 

At 50,000+ miles, these bushings are well on their way out, if not completely expired. Symptoms can and will include play in steering at any speed, click/clunk as you sharply apply the brake, or steering wheel vibration under braking or general looseness in the steering.

Front control arm bushings w/ bracket, link to buy OEM Lemforder or Meyle HD

BMW bushings are great and they maintain the supple yet firm steering feel BMWs are known for. You can take it a step further in both feedback/feel and durability and get a solid rubber design like Meyle HD.

Associated hardware (optional):

Bracket bolts (four per car), link to buy x4 (Meyle HD units come w/ new bolts. If Genuine BMW does too, then no need to order new bolts for the brackets)

Install tips:

If you're replacing just the bushings, you'll need a gear puller to separate the bushing and bracket from the end of the control arm. To reinstall, lube up the control arm and bushing with 1 part soap to 20 parts water and firmly tap onto the arm with a rubber mallet. The end of the control arm should be flush with the end of the bushing. Don't tap on too far and don't tap on too little. When you reinstall the reinforcement plate, make sure you purchase 8 new bolts. These are designed to be changed every time you reinstall the plate. They shear in the event of a crash. You don't want to compromise these very crucial items.

Reinforcement plate bolts: Part number Link to buy all 8 bolts



Struts are in front, shocks are in back. If you have 50,000 or more miles on your E46, your Original Equipment (OE) Sachs-Boge Struts and Shocks are severely degraded, if not totally blown out. You won't notice this because your BMW is stiffly sprung and sway-barred. It will still ride firm, turn sharply, etc. The struts/shocks are crucial in wheel control. Your directional stability is severely compromised when your struts and shocks are failed. This will also cause excess and uneven tire wear. The parts listed below are OE Sport Suspension units. (I'll probably edit this list to include ZHP as well) Keep in mind these part numbers are for OE/OEM units. Many people, including myself, go aftermarket. Personally I went with Bilstein.

BMW performance ZHP, Strut left, link to buy
BMW performance ZHP, Strut right,link to buy

Sport suspension 9/01+ Strut left, link to buy
Sport suspension 9/01+ right, link to buy

Associated hardware

Strut mount (2 per car), link to buy
Bump stop (2 per car), link to buy

Again, these are for stock replacements. Some people go aftermarket as the firmer shocks tend to eat at and destroy the stock design as it is too flimsy. I went with Rogue Engineering.

Strut tower reinforcement plates (VITAL--must install!) two per car, link to buy


Shocks BMW performance ZHP, (2 per car) link to buy
Shocks sport package, (2 per car) link to buy
Shock mount (2 per car), link to buy

Associated hardware

Bump stop (2 per car), link to buy
Paper gasket (2 per car), link to buy
Shock tower reinforcement plates (2 per car), link to buy (VITAL--must install!)

If your bump stops are in good condition, you may reuse. If soft, deteriorated, or chunks missing just replace it. If you go aftermarket Bilstein, they feature internal bump stops. No need for external bump stops.

Install tips:

Perform this work at your own risk. Do not engage in any work that is beyond your comfort and/or skill level. Always secure car on level ground using quality jackstands. Use quality jacks to lift car only, not support.

You will need a quality set of spring compressors, a variety of heavy-duty tools such as a breaker bar, heavy duty ratchet, large socket set and an allen key set (I believe you'll need a 6mm allen key to prevent the strut piston from turning as you undo the top nut.) You'll need a 21 or 22mm socket to undo the top nut. Make sure the socket has a hexed-head on it so you can turn it using a 21 or 22mm open end wrench as you hold the piston stationary using a 6mm allen key. This is self-explanatory as you begin to do the work. A nice electric or air-powered impact gun can also do the job quite nicely.

For installation and torque specifics, consult TIS or a Bentley owners' manual.

Always reuse all washers in correct orientation.
Always replace suspension components in pairs.
Always replace any hardware that is severely corroded or otherwise compromised or damaged.
Always install quality name-brand parts.

Front swaybar endlinks

Chances are your front swaybar endlinks are torn where the rubber boots hold the grease at the balljoints. Replace. link to buy (2 per car).

Rear swaybar endlinks

These are typically solid and last a lifetime. link to buy (2 per car)

Install tips:
Both front wheels have to be unloaded before you begin to remove/install these. Use one 16mm socket and ratchet and a 16mm open-ended wrench on the other side to counter hold the bolt as you loosen the nut. No special tools are needed. These need to be installed TIGHTLY or you WILL hear a clunk or pop while driving over bumps. I can't stress this enough.

Front swaybar bushings
These definitely need replacing. Worn bushings will compromise the response and stability of side-to-side maneuvering. Two per car.

23.5mm for 4/01+ vehicles with sport package, link to buy
23mm (non-sport?) link to buy.

Note: I ordered 23.5mm bushings but received 23mm bushings. I installed them without any problems. Slightly tighter fit.

Rear swaybar bushings


18mm all sedans 4/01+, non-sport sedans up to 4/01, link to buy 
19mm all sedans with sport suspension up to 4/01, link to buy
20mm for convertibles, people who have upgraded, and I believe XIs, part number 33551096669
Bonus: 20mm rear swaybar part number 33556751267

Stage 2 

Control arms

Theres an inner and outer balljoint. Typically the outer balljoint fails first and is encased in nylon (less durable) on non-M and non-ZHP models. It is recommended to replace with ///M ZHP arms or Meyle HD arms.

Control arm left, link to buy
Control arm right, link to buy

Or you can just order the Meyle HD set.

Install tips:

Tools recommended: Front of car on jackstands, medium and large pickle forks, plenty of extensions, wobbles, step-down adapters. Access drivers side control arm inner nut from top and passenger side from down below.

Always buy brand new genuine BMW nuts for the control arms (two per arm) part number, 31106774714 x2, and 32216769539 x2. Do not skimp on these. Do not use the ones supplied by Meyle.

Tierods (complete assembly)

Self-explanatory. Any signs of play, damage or leaking of rubber balljoint casing, replace.

Tierod left link to buy
Tierod right link to buy

Tierood boot kit
Two per vehicle, link to buy

Rear trailing arm bushings:

Replace these at 60,000+ miles. Worn bushings will degrade rear-end stability and basically cause your rear wheels to excessively and unexpectedly to steer. You'll notice this especially when accelerating from a stop.

link to buy (two per vehicle)
Install tips:

Use MIS RTAB tool. Nothing else. Don't even think about it or attempt it. Use large hose clamp in center of bushing to completely compress the split joint as you begin to press it into the trailing arm. Once in, remove clamp.

Be sure to unclip/unscrew main brake line and associated lines clipped onto the trailing arm. Have heavy duty breaker bar and torque wrench ready with two 18mm sockets. Pre-load bushing carrier by aligning the same way it came out. For me the carrier was lined up PERFECTLY with a line naturally casted into the trailing arm. You'll see what I mean when you eyeball it. Worked like magic.

Get an alignment immediately after. Your toe will be WAY out of spec no matter how much you try to get it lined up perfectly.

Steering Coupler/Flex-Disc/Universal Joint

link to buy. Apply blue loc-tite when reinstalling the bolts. Make sure threads are cleaned on all bolts and the two splined shafts which the coupler installs on.

Install tips:

Do this part at the same time as the control arm bushings. The reinforcement plate will have to come off.

Stage 3 

These require tons of labor and special tools. These are for the pickiest of picky. You'll need an E36/E46 rear axle service kit which can be found online.

Rear control arms/trailing arm (except main RTAB because it's listed under stage 2)



Differential Bushing Bolts:

link to buy x2 (Two small diff bolts)
link to buy x1 (One large diff bolt)
link to buy x1 (Self-locking nut for large diff bolt)

Popular Upgrades:

E46 M3 ST Coilovers
E46 M3 Koni Suspension
E46 Hotchkis Sway Bar Set

Thank you for using my links to support me in helping you. Every time you use my links I earn a small portion from your purchase and it doesn't affect you at all. Appreciate it!

Prices, parts, availability, and listings/links subject to change. Do your own research before buying. Thank you!

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