K12GT2 Front Strut Installation

[Limecreek]

Wilbers Strut Installation – Front Strut

 

Part 1

Removing the BMW ESA Front Strut

 

 

I want to warn you right up front—this is neither a quick nor an easy task. It is not complicated, just involved.

 

Before you begin review the entire procedure in the BMW Repair Manual for K Models. After reading the procedure, you may decide it is more than you want to take on. Stop here, pick up the phone and call your dealer for an appointment.

 

Must Have Tools

Torx T30, T55 Thin Wall Socket

Hex H12 Socket

Hex H12 Key

Sockets 18mm, 21mm, 27mm

Cut Out Socket – BMW Part # 90886336641

Torque Wrench with 150 Nm capability

Impact Wrench – Optional but suggested

External Torx Sockets

Scissor Lift

Motorcycle Scissor Lift

 

Note: My old trusty tank bag camera has seen better days and did not consistently function for me, so I am going to use a combination of digital pictures and images from the BMW Repair Manual.

 

Note: I am going to skip any detailed explanation of the more routine tasks that lead up to the front strut removal and replacement. I’ll offer up a few illustrations and a comment or two, and leave it at that.

 

Refer to the BMW Repair Manual for a complete set of instructions on the routine tasks I skip over.

 

Step 1 - Remove the Rear and Front Seats

Step 2 – Remove the Engine Spoiler.

Step 3 – Remove the Left and Right Side Panels.

 

Step 4 – Install the Engine Lifter

BMW repair manual require the use of a proper engine lift and an engine fixture to support the entire weight of the bike. You can purchase the engine fixture from any BMW dealer Part # 90886001573 for $315 or you can build one like I did. (Contact me for a plan and dimensions). There may be other more creative means of supporting the bike and I am sure several of you will use them. I chose to follow the manual and support the bike from below the engine.

 

The fixture has 3 legs; each is secured to the engine. Use 3 cap screws M10-1.50X20. Loosely bolt up the two front legs first and then the rear. Snug them up. Use washers as need to take up excess play.

 

Engine Fixture

 

Engine Fixture Mounted and Supported with a Sears Motorcycle Lift

 

Step 5 – Disengage the ZFE Control Unit Holder

Find the ZFE on the right hand side of the bike. Two screws and a rubber grommet hold it in place. Remove the screws (T30) then pull it from the grommet and let it hang by the wiring harness—don’t worry, it will not damage the harness.

 

ZFE Installed

 

 

Step 6 – Remove the Intake Air Pipe

Behind the ZFE control unit is the Air Intake Pipe. Press and remove the retaining loops up by the Air Box. Work the Air Intake Pipe off the grommet as you slide the base from the Air Box

 

ZFE Disengaged and Air Intake Pipe Removed

 

 

Step 7 – Remove the Wheel and Mud Guard

Check to make sure the entire weight of the bike is supported by the lift. Is the bike stable? You do not want a 600 pound bike falling over, so take your time before going to the next step.

 

Remove the front brake calipers.

Remove the front ABS sensor on the left side of the wheel carrier.

Remove the front beak and mud guard.

Remove the front wheel and then reinstall the axle.

 

 

 

 

Step 8 – Protecting the Wheel Carrier Paint

To remove the strut, you will lift the entire wheel carrier all the way until it comes in contact with the bottom of the oil cooler on the front of the bike. Place some masking or duct tape to bottom of the oil cooler. The tape prevents scratching the paint on the wheel carrier when it contacts the oil cooler in a later step.

 

 

Step 9 - Removing Cables and Brake Pipes

Next you will need to find and remove the brake pipe distributor on the back side of the wheel carrier. Remove the screw (T30). And then trace the brake line back toward the engine where you find another clamp supporting the brake pipe. Remove that one too (T30). And lastly, release the ESA cable, by opening the plastic clamp with your hand. It is to the right of the brake pipe clamp. See the image.

 

Brake Pipe Clamp and ESA Cable Clamp (I do not have an image of the Brake Pipe distributor that is attached to the Wheel Carrier)

 

Step 10 – Unplug the ESA Cable

Trace the cable leading from the bottom of the ESA strut to the plug end. Cut the zip ties along the way. The plug is mounted to the left side of the ZFE control unit holder you removed earlier. It is the second plug from the top with red, green, white, yellow wires. Squeeze the plug and disconnect it.

 

 

 

Step 11 – Removing the Strut Bolts and Link Quick Release Axle

The oil cooler hoses, plastic pipes and the radiator overflow hose on the right hand side of the bike need to be moved out of the way to access the quick-release axle. Disconnect them and push them out of the way. Fluids will drain from them so have a couple of rags at hand.

 

 

Remove the nut (21mm) from the bottom leading link. You will find the nut on the left hand side of the bike. Then go over to the right hand side of the bike and remove the quick-release axle lock nut (27mm) and quick-release axle (H12 hex).

 

Removing Nut (Quick-release Axle)

 

Removing Lock Nut (Quick-release Axle)

 

Removing Quick-release Axle

 

Next remove the lower nut (18mm) and bolt from the lower spring strut. The bolt is an external torx. I did not have the correct size in my tool box, so I improvised.

 

Bottom of Spring Strut – Bolt Gone

 

 

Step 12 – Raise the Wheel Carrier and Free the Strut

Place a scissor lift under the front wheel carrier and lift it until it touches the oil cooler.

 

Raised Wheel Carrier

 

Push link down and way to free the strut. The link may hang on the top of the radiator, so use caution. Do not force it, finesse it.

 

Remove the top strut bolt (T55 torx), from the right hand side of the motorcycle. You can source a thin walled T55 socket at Sears. The bolt has thread locker on it and unfortunately there isn’t a way to get in there with a heat gun to soften it up. So, I elected to use a pneumatic impact wrench to free it. Once the bolt is out, the strut is free to come out the bottom.

 

 

 

 

Part 2 Installing the Wilbers Front Strut

 

 

Step 1 – Introduce the Strut and Fasteners

Introduce the front strut and fasten at the top with a new bolt. (I cleaned the thread locker from my existing bolt and used blue locker. BMW recommends a new bolt). Torque to 35Nm.

 

Lower the wheel carrier with the scissor lift and introduce the lower link back into the frame. The link will try to hang up on top of the radiator. Don’t force it, finesse it.

 

Line up the spring strut and introduce the bolt from the left side. Spin on the nut (18mm) from the left side and torque to 50Nm.

 

Clean the threads of the quick-release axle and lubricate the shank with high temperature grease. Install the quick-release axle through the frame and lower link.

 

Torque the quick-release axle to 20Nm, loosen and the torque again to 7Nm.

 

Install the quick-release axle locknut. Use the BMW cutout socket to torque the quick-release axle lock nut to 145Nm while using the inserted the H12 hex key to keep the axle from spinning. This step took two guys. I torque the nut while my helper held the hex key steady—keeping the torque on the axle at 7Nm and no more. This is a critical step. You can damage the components if you over torque the axel.

 

I do not have a picture of this step, but you can see the cut out socket on the end of the pneumatic wrench in this picture. I used it in this way to release the lock nut during disassembly.

Install the quick-release axle nut (21mm) on the left hand side of the bike and tighten to 30Nm.

 

Quick-release Axle

 

Step 2 - Install the brake pipe clamp on the frame, and install the brake pipe distributor to the back of the wheel carrier. Torque each to 9Nm.

 

Step 3- Install the radiator overflow hose and the hoses to the oil cooler. Make sure the oil hoses are proper seated in the plastic clamps.

 

Oil Cooler Hoses and Radiator Overflow Hose

 

Step 4 - Install zip ties previously removed.

Step 5 – Install the Air Pipe

Step 6 – Install the ZFE Control Unit

Step 7 – Install the Front Wheel

Step 8 – Install the ABS Wheel Sensor

Step 9 – Install the Front Brake Calipers

Step 10 – Remove the Lift and Engine Fixture

Step 11 – Install the Spoiler

Step 12 – Install the Side Panels

Step 13 – Install the seats.

 

[smiller]

Wow Greg, excellent write-up. Just superb. Thanks for being among the first to brave this job, I can only imagine that there were points where you were wondering what you had gotten yourself into. Let's hope the shock holds up so that you don't have to do this again too often...

 

I'm definitely saving this thread for when my time comes up. And looking forward to a similar installment for the rear... Thanks for the time and effort to share your experience with all of us.

[Limecreek]

I finally had a few spare hours to pull my notes and photos together into a write-up. I'll leave the rear strut write-up for next weekend.

 

By the way the Wilbers are perfect. I thought I had a problem with the rear preload, but it turned out to be user error instead. Ted Porter's customer service is just excellent.

 

Cheers!

[Semper_Fi]

Wow - simply fabolous - I like the animation of the shock action.

 

Luckily for me I have no desire to change the suspension.

 

Excellent, excellent work!

[Firefight911]

Holy Toledo!! Fantastic job Greg!!

 

So much for the ease of maintenance days.

 

Let's hope the ESA-II suspenders hold out on the K13. I don't fancy doing this just yet.

[tallman]

Time?

 

I really like the Wilbers on my '03 GT.

[yabadabapal]

Im in tears from reading this. How the heck did you figure this out.

Even with the manual, it looks amazingly difficult.

Thanks so much for sharing and congratulations.

I'm curious also, as Tim was, about how much time it took.

[Limecreek]

Time?

 

I really like the Wilbers on my '03 GT.

 

The front strut took me around 3 hours over a period of a few days. The rear strut (extracting the ESA) took much longer. I'll post that procedure at some point in the future.

 

By the way, a couple of requests have come in regarding the engine fixture I used. I will post a couple of pictures and specs here this weekend. It is not difficult to build one.

[Limecreek]

The base is a piece of 1/2" 12x12 steel.

 

The legs are 1/2" thick and an inch wide. Two of them are 4" tall and the other is 5 1/2" tall. The 4" legs have 1/2" holes and the 6 1/2" leg has a 5/8" whole.

 

PM me if you have questions. Use the PBase site for higher resolution pictures if needed.

 

View of the base plan.

 

 

Side view.

 

[Limecreek]

Correction....thx Seth. 6 1/2" leg

 

The legs are 1/2" thick and an inch wide. Two of them are 4" tall and the other is 6 1/2" tall. The 4" legs have 1/2" holes and the 6 1/2" leg has a 5/8" whole.

 

and...in the picture for the base plan. The 3 1/2" measurement used for placemement of the leg....use the top reference, not the bottom one.