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    
 >  >
Removal and Installation of Tachometer and Clock
 
Bookmark and Share

Pelican Technical Article:

Removal and Installation of Tachometer and Clock

Time:

2 hours2 hrs

Tab:

$200 to $900

Talent:

**

Tools:

10mm Allen socket breaker bar, 6inch socket extension, 2ft long/1inch diameter pipe, flathead screwdriver, Phillips head screwdriver, 6mm socket

Applicable Models:

450 SL R107 (1972-80)

Parts Required:

Tachometer

Hot Tip:

Disconnect battery

Performance Gain:

Working tachometer

Complementary Modification:

Replace the speedometer

There are several reasons why the tachometer or the clock isn't working. The most reasonable explanation is that the gear mechanism has failed. Both instruments are on the same unit.

In order to replace the unit, the instrument cluster has to be removed. Removing the instrument cluster requires removing the steering wheel first. This is a simple task if you use a breaker bar and a steel pipe to counter-act the force needed to loosen the 10mm Allen screw holding the wheel in place. It is estimated that there is greater than 65ft-lbs of torque holding the steering wheel in place. Without the leverage of a breaker bar and a pipe to counter-act the force you will have to use to loosen the screw, you will not be able to loosen it using conventional means.

Before you do any work on your car it is important that you wear safety glasses, work gloves and dispose of all fluids in a safe manner. Protect your eyes, hands and body from dust, debris as well as sharp objects and edges while working on your vehicle. Disconnect the battery before beginning work. Never work on your vehicle if you feel the task is beyond your ability.

Before the steering wheel can be removed, the sheering wheel pad must be removed.
Figure 1

Before the steering wheel can be removed, the sheering wheel pad must be removed. To do this, simply lift the pad off the clips holding it in place.

An alternative method to remove the steering wheel without removing the pad involves the removal of the emblem in the center in order to access the Allen screw.
Figure 2

An alternative method to remove the steering wheel without removing the pad involves the removal of the emblem in the center in order to access the Allen screw. If you do not want to remove the pad you can loosen the Allen screw but you will need to have someone hold the steering wheel in place as you attempt to loosen the Allen screw. Removing the emblem is easy and done so by lifting it off with a flat face screwdriver. 

Once the pad is liberated from the wheel, simply lift it off the clips.
Figure 3

Once the pad is liberated from the wheel, simply lift it off the clips.

Once the pad is removed you will have access to the lead for the horn switch.
Figure 4

Once the pad is removed you will have access to the lead for the horn switch. Disconnect the lead from the wheel.

Slide the pipe through the steering wheel as pictured.
Figure 5

Slide the pipe through the steering wheel as pictured. This will help to provide leverage when loosening the Allen screw. Use a 10mm Allen wrench with a six-inch extension on the breaker bar. If you line up the breaker bar with the pipe, simply force the breaker bar down as you pull the pipe up. Using equal force will allow you to loosen the screw without turning the wheel. After the screw is removed the steering wheel can then be removed. 

Once the steering wheel is removed, the instrument cluster can be removed by lifting the top edge.
Figure 6

Once the steering wheel is removed, the instrument cluster can be removed by lifting the top edge.

Once the top edge is lifted up, pull the instrument cluster forward.
Figure 7

Once the top edge is lifted up, pull the instrument cluster forward. There will be several cables attached to the instrument cluster.

The speedometer cable is attached to the instrument cluster with a cable screw.
Figure 8

The speedometer cable is attached to the instrument cluster with a cable screw. Unscrew the cable from the back of the instrument cluster.

The back of the instrument cluster has a few other cables that are various indicator lights and fluid level indicators.
Figure 9

The back of the instrument cluster has a few other cables that are various indicator lights and fluid level indicators.  

Disconnect the tachometer lead.
Figure 10

Disconnect the tachometer lead.

Disconnect the sensor indicator.
Figure 11

Disconnect the sensor indicator.

There is a plastic part that has to be installed prior to fitting the instrument cluster.
Figure 12

There is a plastic part that has to be installed prior to fitting the instrument cluster.

After the Instrument panel has been removed, flip it over and expose the back.
Figure 13

After the Instrument panel has been removed, flip it over and expose the back.

Using a 6mm socket, remove the screws holding the tachometer to the back.
Figure 14

Using a 6mm socket, remove the screws holding the tachometer to the back.

There will be several screws that have to be removed.
Figure 15

There will be several screws that have to be removed. Make sure you put them in a safe place. Finding replacements is not easy if you lose them.

A plastic harness holds on the instrument cluster wires.
Figure 16

A plastic harness holds on the instrument cluster wires. Take care in removing the plastic harness from the housing.

The tachometer/clock can now be removed and replaced with a working unit.
Figure 17

The tachometer/clock can now be removed and replaced with a working unit. Installation is the reversal of removal.

Bookmark and Share

  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: Wed 12/7/2016 03:06:35 AM