051 Distributor Drive Dog

[George Des]

I'm rebuilding an 051 Distributor for the 230SL and installing the Pertronix ignitor. Replaced all the shims and hardware and beadblasted the body. Looks great with it's new coat of paint. Couple of questions. Every post I've seen mentions that the drive dog on the end has an offset set of drive lugs that must be positioned correctly to mate with the slots on the drive off the oil pump. Got to tell you, I've got two distributors sitting in front of me and the two drive lugs on both not only look exactly alike, but they also look like they are exactly in line with one another. Am I missing something or does this offset apply to other Bosch distributors. I fully understand the problem of putting the distributor in 180 degrees out and will make sure when I pull out my current 09 distributor that I take note of where the rotor is pointing and make sure that the 051 rotor is oriented the same way. The second question is about the vacuum connection. Looks like the stock method of attaching the vacuum tube uses a very small "crush" sleeve that fits over the tube and "crushed" under the screw fitting. The "crush" sleeve on mine is already attached to a very, very small piece of tubing and will in all likelihood not be useful. Anyone figured out a better way to attach the vacuum tubing to the vacuum box on the distributor. Thanks fo all the help guys.  

George Des

[mdsalemi]

George,

Without a doubt, the king of distributors is Dan Caron, Dr. Benz.  Suggest getting on the telephone with him.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[Naj ✝︎]

George,
The lugs are not offset but off-center (if u get my meaning   )
Very difficult to determine when off the distributor. Maybe measuring would help or a 'dummy' pin to test install that the rotor is pointing correctly before fitting the correct (very tight) pin.

New 'olives' are available for the plastic tube. Part # N 003862 004000

naj

65 230SL
68 280SL

[Benz Dr.]

I have a way to do this but it will cost you.....

  The dristributor drive is definately offset. One side is over farther than the other. It may not look like it, and you can force it back into the drive in the housing, but it should just drop in or it's out 180 degrees.

  I always mark them with a punch or sharp chisel before I take them apart. This is very hard metal and won't mark easily. Don't use paint - it won't be there by the time you put it back together.
Put the marks side by side and not all the way cross the bottom. I only made this mistake once - I learn best by mistakes.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org

[George Des]

Dan/Naj,

I must be going crazy because I still can not see the offset you guys are talking about. I'm sure you are right, I just can't tell by looking at it. Maybe I'm not looking at the same thing. When I look at the bottm of the drive, I see a slver circular fitting with two lugs, a wound spring fitted to a slot and the oin that goes through it. Is it the lugs that are offset or are they a different size? It can't be this hard!

George Des

[jeffc280sl]

Hi George,

I missed this myself the first time so don't be concerned.  The base of the round distributor shaft has two rectangular shaped male protrusions.  These male pieces fit into the female slots on the round object in the base of the engine shaft where the distributor fits and locks into position.  Turn the distributor upside down so you are looking at the base piece that I describe above.  If you spin the rotor shaft so that the rectangular male pieces are horizontal you should see that they are not aligned with the horizontal center line of the distributor shaft.  The center line of the protrusions will be either slightly above or below the horizontal center line of the shaft depending on the rotation of the rotor shaft.  Rotate the shaft 180 degrees and the offset will switch from above the center line or below depending on where you started.  

If you were to take the female piece out of the engine shaft and mount it onto the base of the distributor you would see that it only aligns correctly in one position.  If you spin the female piece 180 degrees without changing the distributor shaft you would see that one side of it extends outside the cylinder of the distributor shaft.  The opposite side would be slightly inside the cylinder of the distributor shaft.

I hope this helps

Jeff C.
1970 280SL 4-speed

[A Dalton]

Simply put , the drive dogs are off-set from the drive collar center-line...

[Naj ✝︎]

Pictorially speaking:

Lugs right of center??

Download Attachment: DizDrv02.JPG
27.69 KB

naj

65 230SL
68 280SL

[A Dalton]

quote:Originally posted by naj

Pictorially speaking:

Lugs right of center??


65 230SL
68 280SL

 In your pic, they are to the right of C/L

[George Des]

Thanks all. I'm finally able to see it. What makes this tough is finding a reference to see the offset from. Looks like someone put a punch mark on the one in the photo and that really makes the offset stand out more noticably. Now I really believe you all. I'll try to go back and sort out the Pertronix now. Had it in this morning witht he 051 set up. It started right up and idles fine but was really missing when I brought it out on the road and brought the RPMs up. Put the 09 distributor with points back in and the missing stopped. I'll need to ck what size ballast resistor I've got. I'm using the silver Bosch coil and I believe the resistor is the beige one. Would really like to get this to work because the points routine has been a real PITA. If it doesn't, I still plan to repalce the 09 with the rebuilt 051 and I'll put points abck in this if i can't sort out the Pertronix. Also solved the vacuum connection on the 051 w/o having to use the little "olive". Thanks again guys.

 George Des

[Cees Klumper]

When I rebuilt my 051, I took a bunch of photos during the process. Here's a photo of what this thread is about. Hopefully you can see the offset in this photo + the way I did what Dan has warned us not to do (mark across the bottom, not just on the ends - car purring well though):

Download Attachment: mark it!.jpg
56.02 KB

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[n/a]

George Des

It appears you have the lug discussion settled, but you may have another problem that will definitely prevent you car from running right.  Most of the 230's I have seen came with an 046 distributor.  The 051 distributor came along later.  The 046 distributor is a vacuum advance distributor and the 051 is a vacuum retard distributor.   They will  not interchanage without changing the throttle body as well.  If you put an 051 distributor on an engine that had an 046 distributor without changing the throttle body, the ignition timing will be retarded instead of advancing as the rpm's increase.  

On the subject of electronic ignitions, I put a Crane unit in my 230 SL and helped install a Petronix unit on a friends car.  Both worked well after the installation.  The Petronix was a breeze to install.  The Crane unit was much harder to install because they sent the wrong mounting hardware.  Even with the right hardware, I had to make more modifications to the distributor in order to make it work.  As far as performance, I cannot tell the difference in the two units.  

Good luck on your project.

Iverson

[A Dalton]

The easy way for the eye to pick up the offset is not to look at the dogs themselves, but to look at the area of the "C" on each side of the dogs .. one can easily see the larger C area from the smaller "C " area of the offset side ..
 The "C " area refers to the flat surfaces contained between the ID and OD of the collar... your eye can see this comparison much easier than it can discern the C/L of the collar/shaft...

[Benz Dr.]

Actually, as long as you put your mark anywhere that isn't directly over the pins hole it should go back together right. You need two marks, one on the collar and one on the shaft that will index to each other.
 I've come up with a way that I can change the starting of advance in as little as 50 RPM increments without moving the advance arms, and I don't have to take the whole distributor apart. I can't increase past a certain point but can lower the starting value about 200 - 300 RPM depending on the unit.

Anyone care to guess how I do this?

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org

[George Des]

Iverson,

I have one of the last of the 230Sls made and it originally came with the 051 distributor. The setup on the intake is for the vacuum retard unit, so I know I have the correct distributor. The 09 replacemnt that i put in over 20 eyars ago is also a vaccum reatrd unit but use different rotor, cap and points.

 George Des

[A Dalton]

quote:Originally posted by Benz Dr.

Actually, as long as you put your mark anywhere that isn't directly over the pins hole it should go back together right. You need two marks, one on the collar and one on the shaft that will index to each other.
 I've come up with a way that I can change the starting of advance in as little as 50 RPM increments without moving the advance arms, and I don't have to take the whole distributor apart. I can't increase past a certain point but can lower the starting value about 200 - 300 RPM depending on the unit.

Anyone care to guess how I do this?

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org

 Low end advance start can be changed with diahragm adjuster tension screw on vac element , under cap....

[TheEngineer]

Now here's an honest man:"-I learn best by mistakes" !!

[Benz Dr.]

I rarely change the vacuum advance start as they almost always work right. I sometimes change the total amount of vacuum advance by moving the pull rod in or out.

So, this answer is correct but not what I was thinking about. Think mechanical advance only.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org