Rear Axle Bearing Replacement

books

by Shawn Mahoney

Symptoms:

I wanted to replace my bearings to rid myself of a grinding noise from what I thought was he rear hub. The noise was apparent when the scooter was moving, particularly in third or fourth gears.

I wrote this up because the topic was not covered in the Heinkel Workshop Manual. Thanks to Mike McWilliams on where to start the process.

Repair Time: 3 hours (with the right tools).

Tools Required:

Parts Required:

Parts displayed.

The old seal and bearings are at the top of the picture, along with the spacer. The new parts are at the bottom.

I purchased my bearings from Action Bearing in Brighton, MA. The total for the seal and two bearings was about $16.00 with tax. They could not provide me with unshielded bearings, so they sold me shielded bearings and popped out the shields. Shielded bearings are greased, and you should remove the grease before you install them. The fastest, easiest, (and messiest) way to do this is to blast the bearings with compressed air to blow the grease out.

If you are unable to obtain the parts locally, they are available from the Heinkel Club Deutschland.

Repair:

Prep Steps:

Put your new bearings in the freezer to shrink them, which will ease their installation later.

Disassembly

Tough guy picture.

Remove rear body panel. The body panel is secured by two 10mm nuts under the seat and one 19mm bolt under the spare tire. Don't forget to disconnect wiring harness to rear lights and turnsignals.

Drain swingarm oil. The oil drain plug is a 14mm bolt located on the bottom side of the swingarm. If your swingarm doesn't have a drain plug, you must wait until you remove the rear sprocket cover.

Remove the rear wheel. Depending on your Tourist model, there are four or five 17mm nuts that must be removed.

Remove the rear hub. You will need to remove the rubber cover, the cotter pin, and 24mm castle nut. You can remove the nut with a breaker bar or impact wrench.

Remove rear sprocket cover. There are six 10mm nuts that must removed.

Remove rear sprocket. Remove the cotter pin, and 24mm castle nut, rear sprocket and spacer washers (optional).

Remove axle. Bang out rear axle in direction of muffler. Place the block of wood against the axle so you donít damage the threads when you knock it out.

Snap ring displayed.

Remove seal. You will now be able to clearly see the seal that needs to be removed. Remove the seal with the hammer by using the claw portion and prying it out. You can use a block of wood for leverage. With the seal removed you will now see a snap ring that must be removed to remove the bearings.

Remove snap ring. Use the snap ring pliers to remove the snap ring. Use a large size pliers, it is almost impossible to remove with a small set.

Spacer displayed.

Move bearing spacer. There is a spacer between the two bearings, as well as a snap ring on the inside of the muffler side bearing. You need to displace the spacer to give you a good shot at squarely hitting the swingarm side bearing to remove it. An easy way to displace the spacer is to put the 10mm socket on the end of the punch and hit the punch with the hammer. In the picture below the spacer is visible behind the swingarm side bearing.

Heat swingarm.Heat up the swingarm side case around the bearing for a bout 5 minutes with the torch. Expanding the case will ease removal of the bearing.

Remove sprocket side bearing. Hammer out the swingarm side bearing. Use the long punch to attack it, moving the spacer around to get to different areas. Remove the spacer as well

Heat swingarm. Heat up the brake side case near the bearing for 5 minutes.

All parts removed.

Remove brake side bearing. Hammer out the brake side bearing. You can use the block of wood to ease the process.

Clean. Use a cleaner to thoroughly degrease the hub surfaces.

Reassembly

Heat swingarm.Heat up the muffler side swingarm for a few minutes.

Install brake side bearing and snap ring.Take a bearing from the freezer, wipe off any condensation, and hammer it in, making sure it is in straight and against the interior snap wring. Install the snap ring you removed earlier

All parts installed.

Install the seal. You can put a slight amount of engine oil around it to ease the installation.

Install spacer. Insert the spacer from the sprocket side.

Heat swingarm. Heat up the sprocket side of the swingarm for a few minutes.

Install sprocket side bearing. Take the other bearing from the freezer, wipe off any condensation, and hammer it in, making sure it is in straight and almost against the spacer. Make sure you line up the spacer so the axle will go though before you hammer it home tight.

Install axle. Apply some oil to the rear axle and reinstall.

Install sprocket. Thread the sprocket through the chain and reinstall it. Don't forget the spacer washers if they were previously installed.

Install sprocket nut. Install the castle nut and torque to approximately 110 lbs. Install new cotter pin.

Hold that hub.

Install hub. Reinstall the hub, the spacer that looks like a washer, and castle nut. Torque to approximately 110 lbs. The hub holder pictured below (available for the Heinkel club) is very helpful in this step.

Refill swingarm oil. Uh yes, don't forget this step!

Look for drips. I will say that there is nothing worse than finding leaks once the cases have been assembled. Hopefully you will have no leaks.

After I finished and road tested the scooter, it turns out I didnít get rid of the noise. Finding the final solution will have to wait for the winter, when I can remove the engine and check the small bearing at the top of the swingarm (the next likely culprit).

Documentation

Electrical

Specific Repairs

Repair Journals