Bosch Distributor Refurb

The Bosch distributor on the 1800’s is part number 0 231 115 048 and is made of cast iron.  They typically remain in benign neglect since they apparently continue to work with no issues.   However the precision of your timing will be impacted by the play caused by wear in the moving parts, which is caused caused by all the dirt and grit.

There is a rebuild kit sold under the Bosch part number 1 237 010 007 for “2002 distributors”.  I purchased mine from 2002 AD since I could actually see a photo of the kit and its components.  I suspect this is the same kit sold under a BMW part number through BMW.  The kit is made to work with many different types of distributors therefore there is a large number of parts included not all of which are needed for a single distributor.  As well, many of the washers which appear to be the same are actually of different thicknesses since they act as shims to take axial play out of the rotating center shaft.

All parts in the rebuild kit

Here’s what the typical distributor looks like after years (decades…?) of duty:

Some distributors have c-clips inside the hollow cam shaft retaining it in place; not the 048.  You remove 3 of the 4 visible screws and the assembly pulls up: The screw holding down the points, the one retaining the points wire to the body and the screw holding down the vacuum advance shaft.  Remove the two screws holding the vacuum advance diaphragm housing to the distributor body and it pulls off.  You can now pull out the camshaft and the two plates sitting on top of it.  Those two plates are still held together by the black metal retainer under which there is a small steel ball.  This retainer is held to a vertical threaded eyelet with a screw.  Although my photo shows this screw off while the assembly is still in the distributor, it is much easier to undo this once the assembly is out.  Photos below will help visualize all of this:

Below is the camshaft assembly.  Carefully note the order of the three washers: Thick at the bottom, thinner and then the fiber on top.

Below you can see all the parts and the rebuild kit once they have been cleaned and some of them painted.  

Note that I have already removed the drive gear off the main shaft.  This gear is help in place by a 4 mm pin mushroomed at the ends.  It can be seen in the photo below.  The pin needs to be drilled out.  Be ginger when driving it out since you don’t want to be banging too hard on the main shaft and ruin the bushings it runs on.  This one had no radial play and I wanted to keep it that way.

The shaft, cleaned and de-greased with new shim and fiber washers.  On top of the shaft you can see the plate where the weights slide in and out.  The thin fiber shim provides a low friction, durable surface for the weights to slide.  Mine was not too worn out so I reused it but you can easily cut one of out of Teflon or some such modern, low friction material.

Here you can see the new red fiber washers included in the kit. They go on the weights pivot shafts as seen here.

Weights in place with new retaining clips

One of the weights (right on in the photo) has a longer shaft underneath that fits in an opening on the shaft plate.  This prescribes how much the maximum advance will be.

There is a rectangular piece of oil-retaining felt between the main shaft bushings set in place such that it forms a cylinder wrapping around the main shaft.  You can somewhat see it in the picture below.  It comes out easily and is surprisingly resilient as mine was in perfect condition and sturdy enough to be cleaned with dish washing soap and water and after dry, re-oiled with engine oil and put back in place.

See the felt between the bushings?

After the main shaft is in place comes the task of placing the drive gear back in place and re-pinning it.  The drive pin is spec’ed out at 4 mm x 20 mm.  You can find a roll pin this size at a good hardware store.  It will stick out about a mm on each end but it won’t hit anything.  If you hammer the new pin in you risk damaging the bushings and or shaft and introduce radial play in the main shaft.  This will be manifested as a difference in timing cylinder to cylinder (your timing mark jumps around when setting timing with a timing light).

Use an arbor press to drive the new retaining pin in.

Prevent the shaft from turning while pressing the pin in

This is as far as I could press it since the gear and distributor body get in the way of the press ram.

Use anything that fits in between to continue driving the pin.

The 20 mm pin is a bit longer so it protrudes about one mm on each end but this is not a problem.

Check for axial play on the main shaft. Should be .004. Not perceptible by hand.

Now the camshaft can go back in.  Those little springs are the key to accurate mechanical centrifugal advance.  If they get lost or overstretched, I have no idea where they could be sourced so be very careful with them.  Unless you have a vintage distributor testing machine the only way to test they are performing properly is with a timing light once it is installed in the vehicle.

Camshaft in place with springs attached to the weights.

Camshaft in place with new shim washers in place

The plate on the right is upside down so you can see the mating surfaces that slide to provide mechanical advance.

Both plates assembled and held in place with ball and black spring steel. Now the complete assembly can be slid in place over the camshaft. That's Bosch distributor grease on the steel ball.

In place.

Notice the small felt cylinders placed inside the shaft. There are two. This is service item. They should be oiled (engine oil) until moist but don't flood it. Use distributor grease on the cam itself. It is thick and fibrous so it won't fling all over the distributor.

Kit includes new felt plugs for the camshaft center. New vs. old.

This is the Bosch distributor cap that is now impossible to find. A bit of TLC and it's ready for some more service.

In place and ready to go!

The original style yellow wire capacitors are NLA but they seem to go for a long time. The new ones have a thinner green wire.

Capillary temperature gauge and fuel pump

The early NK cars had a capillary, or mechanical, style water temperature gauge.  I think it changed to electric around ’66 or ’67.  The capillary gauge works on a principle similar to that of a thermometer and bulb where a fluid, ether in this case, expands when heated and acts on a Bourdon gauge which is still found on your basic $20 “mechanical” temperature gauge found at Autozone.

Capillary gauge bulb and receptacle

The temperature sensor, or bulb (top element on the picture above), on these cars is screwed into a hollow cylinder (above picture, bottom) receptacle which itself is screwed onto the cylinder head at the thermostat housing.   The thing missing from the picture above is the capillary tube connecting the bulb to the Bourdon gauge.  When removing these bulbs from the head one must unscrew the bulb off the receptacle by turning the knurled ring since this avoids the capillary tube twisting as it would if you simply unscrew the whole receptacle.  Mine was almost ready to snap having been twisted too many times in the past and when I tried to remove it it snapped.  Immediately you could smell the sweet smell of ether.

The capillary tube is very small and the orifice within it even smaller.  It’s incredibly small.  I have no idea how you’d manufacture such a small-orificed tube.

Can you see the orifice in the capillary tube stump? Click on it to enlarge...

Some folks have detailed online how to go about repairing these by grafting a new  tube and bulb from an off-the-shelf mechanical gauge ( ) I tried to do it *twice* but it didn’t work.  The new gauges’ capillary tube is much larger in ID than these are and although I was able to mechanically match everything as they describe, I don’t think the pressures from the new gauge/bulb combo have enough force to activate the old BMW gauge.  I was able to source an identical gauge on Ebay with a working bulb/tube.  It was also stamped “1965”, something which makes me feel all warm and fuzzy that I’m doing right by my car.

Capillary tube


Below are some pictures of the mechanical fuel pump in various stages of disassembly as I was in the process of cleaning it up and visually inspecting it.   This pump is the same ubiquitous design of seemingly all cars of the era that I am familiar with (Fiat, Citroen and BMW).  It has a built in screen filter plus the carburetor also has a fine filter in it which makes me wonder if a third external fuel filter is needed as these cars were never fitted with one.

Visit to the BMW Museum

Three weeks ago my wife and I had an opportunity to visit the remodeled (2008) BMW museum.  To any fan of the marque, particularly for those of us with an affinity for vintage BMW’s, this was quite a treat.  Only a tour of BMW Classic would top it.

The four cylinder building and the museum 'bowl'.

1500 (model year 1963), the first of the "Neue Klasse" models. The styling of these cars was a departure from prior BMW's and is what's easily recognized as a BMW, with many characteristic styling cues carried forward virtually to this day.

A cloud of model nameplates hangs over the 1500

The gorgeous 3.0 CSi coupe finished in Turkis is placed in a dark room with spotlights shining directly above making it very difficult to photograph well.

A BMW tour guide mentioned that every designer is required to study the coupe as it incorporates so much of the brand's DNA.

Another favorite, the E3 3.3 Li.  The “L” models were long-wheelbase where 100 cms were added between the B and C pillars.

A stack of late 70’s BMW’s: 3, 5, 6 and 7 series.

The timeless 507.  Built between 1956-1959, only 252 were built and MW losy money on every single one of them.

I didn’t read the identifying text, but this 2002 looks to me like the one Mobile Tradition built from scratch a couple of years ago.

A pristine E21 316 sitting outside the museum entrance; making sure no homely 1-series sneaks in…

And finally, the 700

I took many more pictures than I posted here so if there’s anything you are looking for letting me and if I have it I can post it.

Flushing the radiator and polishing the gauges

OK, time to get caught up with the blog.  What a great car season this has been.   Before the hot weather driving season I wanted to ensure the cooling system was up to the job.  I thought it would be relatively clear and clean since I drove it over 1,400 miles between Berlin and Milwaukee and it never even came close to running hot.

Funny enough, this is my first non-daily driver car that has a conventional water-cooled engine.  All the other vintage cars I own or have owned are air/oil cooled: Citroen Ami (two of them), Citroen 2CV, Fiat 500 and Porsche 911.  This meant I had to read  up on all the ins and outs of running a vintage water-based cooling system and how to properly maintain it.   In regards to flushing the cooling system, I reached the conclusion that citric acid was the way to go.  It’s what the Mercedes gearheads use and swear by in many threads such as this one:

You can find the stuff locally at health food stores, but at premium prices.  Also at hydroponic supply stores locally or online but the best deal I found was at bio-diesel supply website DudaDiesel, here: What they use it for, I have no idea; I didn’t want to look too much into it or next thing I know I’ll be trolling Ebay for a 1980’s MB 300D…  I must confess that as a scrounger, the thought of running a vehicle on ‘free’ fuel is tantalizing.

So I get myself 5 pounds of the stuff, some hose fittings at Lowe’s and start flushing the block, after pulling out the radiator and doing the same to it.  The first picture shows the hose simply stuffed into the upper hose using a steel fitting.  The lower one is the hose with appropriate fittings to connect to the hose and to the block drain.

Flushing the block

Block flush hose

There was so much crud in the block that when I removed the block drain plug, not only did not a single drop come out but I had to poke a screwdriver into the opening many times to break through the crud seal that had formed on the inside.  Here’s what it looked like under the car:

Draining the radiator and block

Cooling system residue

I flushed both the block and radiator 3-4 times and ran water through it for at least 20 minutes each time.  The radiator was not as cruddy and I don’t feel that it needs rodding or boiling out.  While it was out I did paint it using Eastwood’s thin radiator paint in order not to clog the fins.  It was too shiny for the core so I re-coated that area with high temperature satin black.

The same day I pulled the gauges out to properly polish the bezels.  They appeared to have light corrosion on them hat would require refinishing.  I was amazed when 0000 steel wool removed 99% of the ‘corrosion’ and polished them up very nicely.  Over the winter, I’ll be sending the speedo to a guy in Germany that can replace the crazed plastic with glass and a new bezel.

Speedo before polishing bezel

Cluster gauge before polishing bezel

Gauges after polishing bezel

After polishing


It was very cool to see that all the gauges had date stamps of 12/65 or 11/65.  BMW Classic’s records indicate this car was built December 1965.

See also the tags found under the seats; no date codes or anything else I can make sense of on this one.  Does anyone know what the numbers denote?

Under-seat tag

This one is dated 11/65:

Next time, capillary gauge and fuel pump.

Gas Tank Gasket Repair and Oil Change

For about half the trip from Baltimore to Milwaukee I had a strong whiff of gasoline in the car caused by bad gasketing of the fuel tank sender.  The guys in Dayton kindly made a temporary fix but once I got home it was time to make a proper cork gasket with some material purchased at Autozone.

It’s also time to renew all fluids.  Being new to the car and not knowing for certain how long they’ve been in, it’s out with the old in with the new.  The oil appeared fresh when we picked up the car in Berlin and it’s been driven around 1,600 miles at this point so I’m probably OK for a few more miles but it’s cheap insurance.  BMW called for a 4,000 mile oil change interval in summer or 2,000 during transition months, winter or with short trips.

I placed an order of common maintenance parts through Walloth and Nesch at, German purveyors of parts for classic BMWs.  Their prices, even taking shipping into account and the Euro exchange, were better than the BMW prices, even withe BMWCCA 10% discount my dealer provides.

This car has a canister and cartridge oil filtration system where only the insert gets replaced.  There is a fiber seal (asbestos in the old days) that seals where the canister lip sits in a grove on the flange, a fat O-ring on top of the cartridge and a rubber insert that sits below the filter and on top of a spring that provides calibrated pressure for the filter to seal against the top which in an overpressure situation (dirty filter) would allow oil to circulate around and bypass the filter.  The fiber seal should be replaced every oil change and the I also replaced the other two rubber parts although they didn’t look to be in bad shape.

Oil filtration parts. The O-ring is not seen here and sits on the flange shaft/tube.

Upon removing the oil drain plug, I inspected the magnetic tip and it showed some ‘fuzz’ but nothing serious.  I’ll have to keep an eye on that in the future and also check compression and leak down of the engine to assess if this might be from abnormal wear but it doesn’t seem to me like it is.

Magnetic oil drain plug as it came out,

Magnetic oil drain plug after wiping the fuzz off

The canister and cartridge came off easily but trying to remove the old fiber seal from the flange was very difficult with the oil filter flange on the engine so out came the flange off the engine block.  Not bad but I had to manufacture a new gasket for the flange-block interface as the old one was toast upon removal of the flange.  Not difficult at all with some cardboard-like gasket material from AZ.  Par for the course with classic car ownership.

Flange with old fiber gasket stuck on it.

Old gasket halfway scraped off

Gasket completely off

Fresh gasket and O-ring in place

Filter paper element spread out for visual inspection. I found no bits of metal or anything else that I could observe.

Back in place

After tightening the canister in place to what felt ‘pretty tight” I had a slow leak  at the canister/flange junction.  I tightened more a couple of times and it would still leak so I pulled out the torque wrench to make sure I wasn’t applying a crazy amount of force.  I went up in force a couple more times until it finally was dry at 30 Lb. Ft. of torque.  Not too much but more than I would have thought.

Pretty satisfying stuff…  But again, simple minds are simply entertained.

This blog sometimes feels like a pretty lonely pursuit; I know that many of you out there are reading it since I see the number of daily hits but I’m getting no comments so feel free to crank it up a little bit and post comments once in a while to spice it up a bit…!

Busted Generator Bushing

As I got to the Milwaukee area and got off the highway exit, I took off my earphones (no ICE on this ride…) and I could then hear a rattle coming from the engine compartment.  I deliberately kept the music volume on my iPod low so I could be fully aware of any noises or other funkiness emanating from the car but this rattle I couldn’t hear.  It was intermittent, loosely corresponding to engine RPMs.  It didn’t sound like big end knocking (thank God!) but I couldn’t pinpoint it; I wasn’t far from home so kept going.  When I got  home I grabbed my mechanic’s stethoscope, one of the most useful, cheap tools you can buy, and determined the noise was coming from the Bosch 6V generator.

The Bosch 6 volt generator (part number 0 101 201 096) has a bearing for the support of the front of the armature (the part that rotates on the inside) shaft and a soft steel (?) bushing for the rear.

Bosch 6 volt generator

Looking down the generator I could see the bushing had worn out to the point the shaft was bouncing around in it and making the rattling sounds.  This photo shows the cavity where the bushing resides, after I took it out with a rented (free; gotta love that program) pilot bearing puller from Autozone.

Where the bushing goes (already pulled out)

Pulled out with pilot bearing puller. The cracks on the bushing developed when pulling it out

Now, here’s where the magic of the internet and Google come in.  I actually found the OEM replacement bearing online.  Wow… this is an obscure part of an obscure component of an obscure car.  How cool is that!  The folks at Wagner Alternators and Supply, have a selection of such parts and the guy I spoke to on the phone was incredibly helpful, spending 10 minutes explaining to me the finer points of getting the bushing out and installing the new one.

Ahhh... brand new bushing. I bought two.

Old vs. New

The shaft got a little buggered up. Some emery cloth and steel wool brought it back to 98% of what it should be

Brushes look good so no worries for now.

I put it back together, put it on the car and was careful to not over tighten the belt.  In fact, it looks a little loose to most people but the generator and water pump put very little load and that belt so keeping it loose, just short of it slipping, is the way to long term bushing happiness.

My next post will deal with the gas leak from the sender which had me breathing gas fumes for the back half of the trip.

The last leg: Baltimore – Milwaukee

Now that I can upload pictures from my camera here are are a few I was unable to post before.  Here’s the meeting point with A-1 Escort, an out of the way semi / container parking lot, where I could have gotten mugged and I doubt anyone would have noticed.

Kelly's blue jeep, getting paperwork ready to hand me off to Naomi

I hadn’t driven more than a quarter mile when I hear the soft muffled sound of something falling off the car. I look in the rear view mirror and make a mental note of where I was to come back after I fuel up not far away.  I go another 1/8 of a mile and now something more significant falls off (what is this a Triumph?!), I glance back and I see the rear “1800” badge and roundel skipping on the road.  I’m in an underpass with no shoulder so I quickly drive a bit farther up and pull into one of the many abandoned, fenced lots.


My badge and roundel are somewhere on that road and the sidewalks are up about 8-10 feet. Traffic was light but it's all cranky semi drivers at twice the speed limit.

I run down the sidewalk up to where I see my NLA badge and pricey roundel laying on the road, just asking for a 10-ton semi to drive right over them.  I climb down the retaining wall and incredibly I’m able to retrieve the runaway parts prior to any semis flattening them.

They were largely unscathed

De-badged 1800...

The badge coming off was a result of many trunk lid slammings all trip long since the seals are still fresh and the latch needed adjustment.  I placed the badge back in place and it seems tight for now and later stop at an Autozone and buy a missing retaining clip.  This day was a real scorcher in DC/Baltimore; it was around 86 degrees and 90+% humidity.  When I try to start the car, repeated cranking attempts get me nowhere; this deja vu all over again!! (see “In Berlin: The Pick up (and the stall) ).

Stalled again

Once I get my head under the hood I see this is only a case of the carb flooding, so I just let it dry out for a while and it eventually starts.   It was never even close to being this warm in Europe.  During the course of this long trip to Milwaukee, the car and I soon understand each other better and it reveals to me that when it’s hot, I need to crank it for a couple of seconds, stop, then crank again and it starts immediately.  We’re good.

I then go back to retrieve the first lightweight, small mystery part that fell off.  It took me a while but I found it.  It turned out to be a short piece of paper-covered air intake tube that German cars of this period have.  It connects the thermostatic intake box and the air filter box.  That whole assembly needed attention in Europe so it wouldn’t fall off and I’ll have to permanently fix it when I get home.

I stay at my sister’s house in DC that night (thanks Susi and Ceci!) and set out for Dayton, OH, 486 miles away, at 9:00 am.

A few weeks ago I had contacted Mike Self, BMWCCA member and Roundel magazine columnist (“02 Cents Worth”) and seeing that I was driving near Dayton, decided to pay a visit the very night the local BMWCCA Buckeye chapter was having thir Spring Kickoff get together at Dave and Deb’s Castle’s home in Troy, OH, just north of Dayton.

Welcome to Ohio

What a great evening spent in the company of BMW enthusiast, and a phenomenal dinner spread, thanks Deb and Dave!  Dave has the sweet set up in his large pole barn with a two-pole lift and when he volunteerd to put the 1800 on it, I jumped at the opportunity.  I had not yet fully seen the underside of the car and I was very pleased with how clean and well finished it looked.  If you look closely at one of the pictures below you’ll see that I lost the “8” in the 1800 badge at some point between DC and Dayton.  It’s killing me…  The badge is “no longer available” so I’m trying to scrounge one anywhere I can find it.

Long neck differential

Dave checking out the loose fan belt

At some point during the drive, the car developed a gas leak and the fumes were pretty strong in the cabin, I just kept going relying on the 4-70 (4 windows, 70 mph) air conditioning to carry the fumes away.  Mike and Dave crafted a provisional gasket; thanks guys!

Dave and Mike Self fashioning a field-improvised fuel sender gasket so i can make it home with minimum brain damage

Over the course of the first leg of the trip to Dayton, the car more than kept up with traffic, as you can make out from the Garmin display below; an average of 64.1 mph for a 498 mile trip; not bad for a 44 year old car with 90 horses.

I stayed in a hotel in the Dayton area that night and headed home the next morning.  The second leg of the trip consisted of 392 miles.  A total of 888 miles, plus 600 in Europe, nearly 1,500 largely trouble free miles.  The engine feels strong and smooth and the car very tight and well sorted.

When I arrived home in Milwaukee the car had an alarming rattle/clunking sound coming from the engine compartment.  I’ll report on what happened and the fix on the next post.