Repairing worn tongue and groove slot in front brake backing plate

The tongue and groove slot which holds the front brake backing plate on many vintage models of BMWs often becomes worn. This results in annoying click or clunk whenever the brakes are engaged, or when the bike rolls to a stop.  Scottie's can machine these new parts to "like new" condition to repair this problem. Machine shop time is about 2 hours. Call us for details.

Once new metal is added by TIG welding, the part is machined.

The result is a precise "like new" part and a precise fit.

Installing factory style wire ties

BMW used metal wire straps on several locations on the BMW /2 models. There are large ones and smaller ones.  Oftentimes these straps are missing.  I believe the stock locations are as follows.  There may also be a large strap on the right downtube to affix the clutch cable. I am seeking information from those who have original bikes or documentation on the location of these straps.  Please make a comment if you have any information.

The factory straps look like this.  I believe they were painted black.

Benchmark Works has reproduction straps in stock. They are very well made. They come unpainted. 

• 61 11 8 070 114--$3.00--metal wire tie 135mm small
• 61 11 8 070 118--$3.00--metal wire tie 180mm large

To discover how to make the strap "buckle" look the way the BMW factory did it, I unfolded a vintage strap.

Disecting the factory tie, notice that the strap is run through the "bottom" of the buckle and back down into the top of the buckle.  

The strap is cut near the top and then the buckle is pushed down, locking the strap, and hiding the cut end.

To re-create that, the new strap is put in place and the buckle part is lifted up.  The end is fed through the top slot, then back in the bottom slot and trimmed. Then the buckle can be folded down.

A pair of wire rolling pliers helps tighten up the strap.  I decided to use the straps unpainted and see how they hold up.

Unlike the rest of the harness, the engine ground and neutral indicator wire are held to the frame just fore of the rear fender with spring clips.

Reaming out newly painted frame

I reamed all of the tapped holes on Ned's frame. I didn't have a tap for the rear swing arm pivot bearing pin adjusters so I made a tap out of an old pin I had lying around.

Worked great and now I have a new tool!

Replacing brake shoe linings on a BMW /2 Motorcycle

It's not often you replace your brake linings.  They really last a long time. However you should inspect them every time you have the wheel off to make sure that they are clean and dry, and not too worn.

These are getting a little thin.  See how close they are to the rivet?    

The rivets are made from copper which is a soft metal which will not damage the brake drum. 

New Brake Linings. These are new old stock OEM from West Germany when Germany had an East and West, however you can also buy raw lining material and cut your own. The benefit of cutting your own material is that the performance is GREATLY improved due to the new technology employed in the friction surfaces.

Several different kinds of brake linings for /2. My current favorite is the VB3000 lining from Vintage Brake in Sonora CA.



To remove the old shoes, use a SHARP 1/8" drill bit to drill out the head of the rivet. You only want to remove the head. Do no drill too far. Don't damage the shoes, or enlarge the hole in the shoes.  You can also use a lever to pry off the old brake shoe, breaking it apart. Use side cutters to remove the loose rivets.

Clean shoe and line up the new lining.

Grab yo self a box o rivets.

The rivets are inserted with the heads on the lining side.  From underneath, a center punch held in a vice supports the rivet head.

Squeeze the pad to the shoe when peening the rivet. Make sure it is tight!

You can use a pop rivet tool to start the rivet, however I recommend hand-peening to get maximum tightness. I made a small peening tool to form the rivet head, however hand-peening with a ball-peen hammer is perfectly acceptable.

Stock linings last a long time!  I think that date is 12/66 !!

Looking so fine!

When reattaching shoes to the front brake, don't forget to attach the small lever return spring.

And the other side.

The brakes are ready to install.

And I'm ready to call it a day!

BMW /2 Swing arm leaks, final drive leaks

During a routine oil change, it was noted that the drive shaft housing was empty.   Could it have been stolen by vagrants?   A guy works hard for his oil just to have vagrants come and steal it.

Well, before contemplating a move to a safer neighborhood, BMW riders should remember that oil migration from the drive shaft housing to the rear drive is a common problem. 

There are three ways that oil can migrate from the driveshaft housing to the final drive and they all have to do with the input gear on the final drive.  This little guy:

Here are the three ways oil can get around this gear and into the final drive: 

1. Through the seal. 

2. Through the splines.

3. Through the threads which hold the collar in place. 

The solution is to goop them up with non hardening sealant.  Old timers used to use Hylamar, available from S. Meyer in Germany and other dealers.   

Some stores still stock Permatex.  For example, http://automotive.hardwarestore.com/90-558-gasket-sealer/hylomar-universal-blue-sealant-665467.aspx?utm_source=pla&utm_medium=cpc&utm_term=&utm_campaign=rkg

When assembling the final drive input gear, clean parts thoroughly in solvent or carburetor cleaner. 

Apply Hylomar or equiv. to the threads of the pinion gear bearing locking ring. 

Apply a touch of grease to the seal surface of the coupling gear. Don't put any Hylomar on the seal. It's only for the splines and threads.

Next, apply Hylomar to the bottom of the splines on the coupling gear. 

Install the gear and apply more Hylomar. 

Install the locking ring (bent washer with positioning clip) and nut. 

Failure to properly seal the splines and threads will allow oil to migrate from the swing arm into the final drive, over filling it. This is not a catastrophic situation, although it can lead to a leaky rear drive and oil-saturated rear brake shoes if the drain hole in the final drive is not clear. 

If you do have a leaky pinion junction, you may notice that the fill plug of the final drive overflows when you remove it. To correct the situation,  reduce the oil level in the Final Drive to just below the fill plug with a turkey baster and transfer this fluid to the prop shaft. If the fluid is contaminated, do not reuse it: rather empty prop shaft housing at swing arm drain plug and refill prop shaft with 150cc of 90wt gear oil.  The manual says to use motor oil, but I suggest that you use something thicker if you want to live with this issue. 

Installing new tapered steering head bearings and headlamp nacelle mounting

These new tapered steering head bearings should be a standard upgrade on any Slash Two that still has ball bearings in the head stock.

I removed the bearings and races in a previous blog post. Now we are installing the new bearings. 

Tap the bearing races home with a suitable drift and heavy mallet. 

Removing the old races from the nut isn't a problem if you....

Stack the assembly on a 22mm socket.

Then place a 41mm socket on top and tap with a plastic mallet.

Even though the new bearings came greased. I like to thoroughly clean them with solvent and run them in my fingers to check for smoothness. 

Then I grease the bearings in my trusty bearing packer.  Compared to a royal sized mess packing using your fingers, this method only makes a medium sized mess!!

Tap down the inner race on the fork using a brass drift.  Tap only on the inner race and go evenly around to ensure it settles in evenly.

Press the other bearing inner into the cap nut using a vice.

Arrange some support for the fork and front suspension assembly.

Locate the fork in the head stock.

Spin on the nut and cap assembly and tighten down past the point of snugness.  You want to settle the bearings, then back off to the point where the play is eliminated.  Go back and forth a few times to make sure you have it right. You want to snug it up just to the point where the play is eliminated.

When you put the upper fork plate on, check the clearance provided by the old spacer. It may have changed with the new bearings. If so, get a different spacer, or add spacers. You want the plate to settle evenly on the outer fork uppers and the inner nut cap.  You don't want the plate to bend when you tighten down on center nut.

Now we'll mount the head lamp nacelle. Place a piece of rubber hose about 3/8" long in the hole.

Arrangement order: outer washer, rubber washer, headlamp ear, rubber washer, headlamp shell.