How to Check and Replace the Starter Motor in a Car

How To Replace Starter Or Dynamo Bearings?

If you’re keen on learning how to replace starter or dynamo bearings, we have curated the perfect article. From testing the dynamo bearings using a battery to replacing the bearing, this article will cover all the basics involved for anyone willing to learn how to replace starter or dynamo bearings on their own.

Signs you need to replace a starter or dynamo bearing.

One of the most prominent signs that your vehicle’s starter or dynamo bearing needs replacement is that you will start hearing loud clicking more frequently. You’ll hear this noise with the key turned. The click sound will often be a single noise or persistent oud clicks.

Other common symptoms you’ll observe include buzzing and grinding noises. In addition, the car’s engine will either not crank consistently, or the car will not start properly.

How to replace starter or dynamo bearings

Starter bearings are mostly composed of graphite and bronze. Furthermore, heavy-duty starters’ pinion end has ball bearings. Now, check for wear and tear on your starter, remove after removing and before dismantling it. Now, push the shaft from both sides while gripping the pinion. This lengthways movement is referred to as end float. The end float shouldn’t be more than 3 mm.

Get new bearings before replacing the older ones. You can easily find them at auto-electrical stores. Riveted covers are installed at the end of the commutator. They need to be drilled or jerked out if you want to replace them.   

Now, start dismantling and stripping the motor. Firstly, take the endplates and bearings off. Then separate the commutator and the dynamo brush assembly.

Dynamo Bearings

Dynamo bearings are very similar to starter bearings. They consist of a ball bearing at the end of the pulley. Now let’s begin with the right way of removing dynamo bearings. Before fitting a dynamo bearing, it’s important to repolarize it. However, you need to repolarize when the dynamo is fitted in place. Connect the car battery terminal to a cable. Then, for two seconds, connect the terminal and the other end. Lastly, normally connect the dynamo and test it. (Check out How to Fix a dynamo)

Take the bushes out

Push the bushes inside. Some bushes are capable of moving only in one direction. So, push the new bush from the endplate’s inner side. The simplest way of removing a bush is to make the endplate stand. It should be stood inner side down with open jaws leaving ample space for the push to go through. Then, use a hammer to knock it out.

Cut the bush using a chisel if it doesn’t budge. Cut inside one of its sides to split it. However, be careful not to damage the alloy housing. Screw it to the point it has a tight grip. Then, pull out the bush and tap simultaneously.

New bushes

Before you press them in, the new bushes should first be soaked in engine oil for at least a day. You can also tap them in by drifting them in through a socket. Keep the bush straight while tapping it inside. Ensure that the bush fits the armature’s shaft tightly. In addition, the shaft shouldn’t be worn out, and it should be gouge and groove free.  

The most convenient way of fitting a bush is to press it using a vice. However, this method requires you to have a tool with a diameter similar to the bush. Now, the bush and housing should be lined while being accurately square with each other. Then, press the bush in. If you don’t place the bush in line with the housing, it will distort. In addition, no damage or signs of wearing should appear on the end. Lastly, you can also use a socket spanner to gently tap the bush inside.   

Bearing removal

Firstly, pull the armature from the starter. Remove the retaining key, pully too, and finally the front bearing. Now, the bearing’s inner race is firmly fit on the armature’s shaft. However, it’s slidable. Now, tap the shaft out gently using a hammer. While holding the front plate, the inner race will be free.

Another method is to grip or support the front plate and then tap out the shaft from the bearing. An internal clip or a retainer plate usually holds the bearing in the front plate. However, whichever method you choose, make sure the armature doesn’t fall off.

If a circlip holds the bearing, use pliers to remove the clip. You can also use a screwdriver and tap it out.  Underneath, no felt washers or spacers should be left. However, you need to reassemble them back in the exact order. Lastly, separate the rivets from the retaining plate using a drill. You will also have to replace the washers and place them back in the previous order.

Bearing replacement

The last step involved in learning how to replace starter or dynamo bearings is to learn bearing replacement. Firstly, fit the spacers and felt washer back. Then, replace either the retaining clip or the circlip. To keep the rivets firm on the plate during retaining plate replacement, ensure they are properly splayed 

Estimate the cost to replace a starter or dynamo bearing

Each part has a different cost. Some parts cost only a mere $50, while some cost a whopping #350. Furthermore, if you assign the replacing or rebuilding to an experienced mechanic, the cost will range from $150 to $1000.

Is learning how to replace a starter or dynamo bearings difficult?

  Learning how to replace starter or dynamo bearings isn’t very difficult. Anyone with a general overview of the engine can do it easily on their own. However, you might have difficulty with large vehicles as their engines are much more complex and difficult to handle.

Final words

If you’re an avid driver, you must know car maintenance like the back of your hand. If learning how to replace starter or dynamo bearings seems complex for you, start with simpler things. You can start by learning basic skills like refilling a sealed cooling system, replacing core plugs, or checking your car’s instrument. Then, when you’re ready, you will be able to wrap your head around much more complex tasks.

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