How to Remove and Fit the Distributor in a Car's Ignition System

How to Overhaul a Bosch Distributor?

A distributor is an essential component of the ignition system that is connected to the engine. Bosch distributors are very durable and are found in most cars. However, after a couple of thousand miles, the mechanical advance mechanism of a Bosch distributor might cause a decreased acceleration. Overhauling a Bosch distributor to free the advance weights is an easy procedure that requires simple tools like a screwdriver. You may also want to look out for other minor replacements during the overhauling process. Read on to find out how to overhaul a Bosch distributor on your own.

Bosch Distributor

A Bosch distributor is similar to any other distributor with some minor exceptions. For instance, in a Bosch distributor, a condenser is mounted outside of the distributor housing.

Some Bosch distributors, depending on your car’s make, also have vacuum advance units attached to them on the side. The vacuum advance unit is usually connected by a circlip and a link rod to the post of the upper moveable plate of the distributor.

Like most distributors, the moveable plate sits on a baseplate and has contact-breaker points.

How to Overhaul a Bosch Distributor?

Overhauling a Bosch distributor is an easy task but make sure you remove your car’s battery to avoid any electric shocks while taking the distributor out of the car.

Removing a Bosch Distributor

Follow the following steps for removing a Bosch distributor out of your car:

Step 1 – Locate the distributor beside the engine block and, using a screwdriver of an appropriate size, carefully unscrew the condenser mounted on the housing.

Step 2 – Disconnect all the electrical connections and the high-tension plug leads from the distributor cap. Make sure you mark the leads using pieces of masking tape so you can remember which lead goes in what slot in the distributor cap.

Step 3 – Now unclamp the cap and take the distributor out of the car. 

Step 4 – Carefully remove the rotor arm and the contact breaker points from the plate.

Step 5 – Using a screwdriver, remove the circlip holding the vacuum advance link in place. Keep the circlip on the side so that you don’t misplace it.

Step 6 – Now, free the vacuum advance unit from the distributor housing using a small screwdriver.

Once the additional components have been removed from the distributor, you can now overhaul the distributor for very specific replacements. If there is major damage like a fault in the mechanical advance unit, it is best to buy a new distributor since the replacements are very difficult to find.

Inspecting Bosch Distributor Components

Follow the following steps to inspect a Bosch distributor:

Step 1 – A small felt pad that retains a small amount of lubrication is present at the very top of the distributor shaft. Remove and replace the pad if it appears worn out. Make sure you add a few drops of machine oil on the new pad before putting it in.

Step 2 – The baseplate and the clips that hold the distributor cap in place are both secured by two secures. Using a small screwdriver, remove the screws to take the clips off and lift the baseplate.

Some baseplates are sealed inside the distributor. If you are unable to lift the baseplate out easily, lever it out using a screwdriver but make sure you don’t end up damaging the plate or the insides of the distributor.

You have to notice the position the baseplate is set in so you can place it back in that exact manner later.

Step 3 – Once the baseplate is removed, you now have access to the mechanical advance unit. The weights of the unit should be able to move about freely without any hindrance. Using a screwdriver and a small amount of oil, lubricate the weight pivot posts until they can move about freely.

Step 4 – Now check the advance weight springs. These springs are held in place by mounting pins. Ensure they are in their place; if not, use long nose pliers to place the springs back on the mounting pins.

Step 5 – If the drive gear at the end of the shaft appears to be worn out, replace it with a new drive gear of the exact same size. You need to take out the rolling pin that keeps the gear in place to remove the drive gear. Use a hammer and a pin punch to tap the pin out gently.

When putting in new gear, you’ll have to hammer in a new rolling pin as well.

Step 6 – Look for any worn-out rubber washers and replace them for a smoother performance by the distributor.

Reassembling a Bosch Distributor

Once the changes have been made, reassemble the Bosch distributor in the exact way you took it apart. When adjusting and fitting the contact-breaker points, make sure that you check the dwell angle; otherwise, you will experience starting issues. Fit the condenser and place the distributor cap, and plug leads back in their place.

Additional Measures

Following are some additional measures that you should consider taking for a better performance of your car:

Now start your car and take it for a test driver.

And there you go, simple and easy steps to ensure that your engine operates at its optimum level. Knowing how to overhaul a Bosch distributor can give you the confidence to make easy replacements on your own. By learning these simple steps, you can not only significantly improve your engine’s performance but can also save lots of money by doing the replacements instead of buying a new distributor.