Mercedes-Benz Parts Catalog Mercedes-Benz Accessories Catalog Mercedes-Benz Technical Articles Mercedes-Benz Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
Replacing the Steering Rack on a W220 S-Class
 
Bookmark and Share

Pelican Technical Article:

Replacing the Steering Rack on a W220 S-Class

Steve Vernon

Time:

5 hours5 hrs

Tab:

$340

Talent:

**

Tools:

Metric wrench set, two 18mm socket sets, E8 Torx socket, breaker bar, small pliers

Applicable Models:

Mercedes-Benz W220 (2000-06)

Parts Required:

New steering rack

Hot Tip:

Get oil dry as some steering fluid will spill

Performance Gain:

Quiet steering

Complementary Modification:

New Tie Rods

Mercedes-Benz W220 models are known to have issues with the steering racks as the cars get over ten years old. While this can be a messy job to "Do it Yourself", you can save a lot of money in labor verses having a shop do it. The hardest part of the job is seeing what you are doing while the rack is still in the car. Lucky for you we have taken pictures of everything out of the car so you will know what you are feeling around for.

Begin by safely raising and supporting the car off the ground. Please see our article on raisings and supporting your Mercedes. Give yourself as much room to work under the car as you can. The steering rack is a tight fit and you will appreciate any extra room you can give yourself once you start working under the car. You are only going to be unplugging one electrical connection, but I always disconnect the battery whenever I am working on any car, so go to the trunk and disconnect the ground terminal and make sure it can not make incidental contact with the battery post while you are working. Note: the steering wheel and front wheels should be straight before removing anything.

Open the hood and remove the driver side air inlet. It simply compresses and pulls away from the engine, then pulls out from the cold air inlet by the radiator.

Clean around the cap of the power steering reservoir so you do not get any dirt into the power steering system and then remove the cap. Use a turkey baster or hand pump to remove as much fluid from the reservoir as possible.

Move to underneath the car and remove the under body trays. There are two trays that are held on by eight 8mm screws. It is a good idea to remove the trays before you disconnect power steering line so you can put a drip pan under the car to catch any extra fluid.

While you are under the car you can detach the tie rods from the steering rack. Use a 21mm wrench and loosen the nut on the steering rack back towards the rack itself, then using a 15mm wrench turn the rod on the steering rack until it unscrews itself from the tie rod. Note: you will need to have an alignment preformed after this job, but it is a good idea to note how many turns or the length of threads showing on the old rack so when you install the new rack you can get the alignment close enough that you will not damage your tires driving the car to an alignment shop.

Move back to the engine compartment and use a 17mm wrench to disconnect the upper line from the power steering pump. Be prepared to catch the remaining fluid that will drain out of the reservoir.

Working from under the car again separate the steering coupler from the steering shaft by removing the bolt that attaches it to the diaphragm.

It is very hard to see the next few steps so be prepared to feel around, use our pictures for reference and take your time. Begin by removing the wiring connector on the solenoid at the top of the steering rack and then remove the cover over the coupler. The cover is held on by two female Torq E8's: one by the solenoid on top, and one by the fluid lines on the side. With the cover off you can remove the nut and bolt holding the coupler to the steering rack. With the nut and bolt removed the coupler will slide straight back and off.

Using a breaker bar remove the four 18mm nuts and bolts holding the rack to the sub frame. Use caution as once these bolts are undone the rack is free and will fall if you do not support it. Pull the rack forward and disconnect the line on the very back of the rack. You do not have to remove the line towards the front of the rack if you don't want to, as it will come out of the car with the steering rack assembly. With the rear line disconnected you can remove the rack from the car.

Take the rack to your bench, remove the forward line and transfer it to your new rack. The new rack will come with a safety circlip and protective sleeve over the shaft. Remove the clip and sleeve and install the rack into the car, there is a cut out groove in the spindle that needs to line up with the coupler so you can get the securing nut and bolt through. Do your best to line the coupler up on the new rack as close as possible to how it came of the old one. This will help keep the steering wheel level when reinstalled. Feed the attached line through until you get the rack in far enough that you can connect the rear line. With the rear line connected loosely bolt the rack in place. From this point installation is the reverse of removal. Once you have reconnected the power steering line and filled the reservoir, reattach the battery but DO NOT start the car. With the ignition unlocked turn the steering wheel curb to curb 30 times. This will help purge the air from the system, failure to do this will cause air to be trapped in the system and result in a noisy and improperly working rack. Make sure you fill the reservoir to the correct level as the system is very level sensitive.

Remove the ground terminal (yellow arrow) from the battery located in the trunk and secure it so it can not make contact with the battery while working.
Figure 1

Remove the ground terminal (yellow arrow) from the battery located in the trunk and secure it so it can not make contact with the battery while working.

Open the hood and remove the driver side air inlet.
Figure 2

Open the hood and remove the driver side air inlet. It simply compresses and pulls away from the engine (green arrow), then out from the cold air inlet by the radiator (red arrow).

Clean around the cap of the power steering reservoir (red arrow) so you do not get any dirt into the power steering system and then remove the cap.
Figure 3

Clean around the cap of the power steering reservoir (red arrow) so you do not get any dirt into the power steering system and then remove the cap. Use a turkey baster (yellow arrow) or hand pump to remove as much fluid from the reservoir as possible.

Remove the two under body trays by unscrewing the eight 8mm screws holding it in place (yellow arrows).
Figure 4

Remove the two under body trays by unscrewing the eight 8mm screws holding it in place (yellow arrows).Next you can detach the tie rods from the steering rack (red arrows).

Use a 21mm wrench and loosen the nut on the steering rack (green arrow) back towards the rack itself, then using a 15mm wrench turn the rod on the steering rack (yellow arrow) until it unscrews itself from the tie rod.
Figure 5

Use a 21mm wrench and loosen the nut on the steering rack (green arrow) back towards the rack itself, then using a 15mm wrench turn the rod on the steering rack (yellow arrow) until it unscrews itself from the tie rod.

Use a 17mm wrench (red arrow) to disconnect the upper line from the power steering pump.
Figure 6

Use a 17mm wrench (red arrow) to disconnect the upper line from the power steering pump. Be prepared to catch the remaining fluid that will drain out of the reservoir.

Disconnect the steering coupler from the steering shaft (green arrow) by removing the bolt.
Figure 7

Disconnect the steering coupler from the steering shaft (green arrow) by removing the bolt. You will need to remove the coupler cover before you will be able to remove it from the rack (yellow arrow).

This photo illustrates the steering coupler attached to the rack with the cover on while it is out of the car, so that you can see what you will need to do while it is in the car.
Figure 8

This photo illustrates the steering coupler attached to the rack with the cover on while it is out of the car, so that you can see what you will need to do while it is in the car. Begin by removing the wiring connector on the solenoid at the top of the steering rack (yellow arrow) and then remove the cover over the coupler. The cover is held on by two female Torq E8's (green arrows): one by the solenoid on top, and one by the fluid lines on the side. With the cover off you can remove the nut and bolt holding the coupler to the steering rack. With the nut and bolt removed the coupler will slide straight back and off. Also shown are the inputs for where the power steering lines go (red arrows).

This photo shows the steering coupler off the rack and out of the car.
Figure 9

This photo shows the steering coupler off the rack and out of the car. It attaches to the rack by a nut and bolt through the hole shown by the red arrow.

Using a breaker bar remove the four 18mm nuts and bolts holding the rack to the sub frame (red arrows).
Figure 10

Using a breaker bar remove the four 18mm nuts and bolts holding the rack to the sub frame (red arrows). Use caution as once these bolts are undone the rack is free and will fall if you do not support it. Pull the rack forward and disconnect the line on the very back of the rack. You do not have to remove the line towards the front of the rack if you don't want to, as it will come out of the car with the steering rack assembly. With the rear line disconnected you can remove the rack from the car.

The new rack will come with a safety circlip (green arrow) and protective sleeve (red arrow) over the shaft.
Figure 11

The new rack will come with a safety circlip (green arrow) and protective sleeve (red arrow) over the shaft. Remove the clip and sleeve and install the rack into the car. There is a cut out groove in the spindle (yellow arrow) that needs to line up with the coupler so you can get the securing nut and bolt through. Do your best to line the coupler up on the new rack as close as possible to how it came of the old one. This will help keep the steering wheel level when reinstalled.

Bookmark and Share
Comments and Suggestions:
onebadx Comments: nicely written article with good pictures.
Do the 4matic w220 cars use the same procedure?
Thank you,
June 13, 2016
  Followup from the Pelican Staff: No, the procedure will be different. - Nick at Pelican Parts  
Andrew Comments: Is the W210 1999 E320 with servotronics steering rack replacement similar to the W220 procedure on your web site? So the outer tire rod ends do not need to be removed from the steering knuckle for steering rack replacement-i.e., can just disconnect at nut for inner tire rod? I don't have any experience with repair on steering components, but your W220 procedure does seem like it may be the '2' level difficulty that you rate it at. Just wondering, is the steering rack replacement for 1999 E320 similar? Also, should I buy a flare wrench for removing power steering hose? Thanks. - Andrew
July 3, 2015
  Followup from the Pelican Staff: See this tech article:

http://www.pelicanparts.com/techarticles/Mercedes-W211/115-SUSPEN-Power_Steering_Rack_Replacement/115-SUSPEN-Power_Steering_Rack_Replacement.htm - Nick at Pelican Parts
 

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Project/Wish List]
  [Privacy Statement]  [Contact Us] [About Us] [Shipping] [Careers]

Copyright © Pelican Parts Inc. -    DMCA Registered Agent Contact Page

Page last updated: Sat 12/3/2016 02:31:58 AM