Restoration Difficulty Level

[bsimaz]

If you still need any info... I came across this in an old workshop manual.

[Rodolfo]

Andy,

Thanks a lot for the measurement. I can use that info, Glad we helped each other. That is really  where this great forum is about, Rudy

[andyburns]

Thanks Bill, thats really kind of you to supply that breakdown.

Things have move on somewhat.  ECS Tuning have come back and refused to tell me who is supplying them with their parts and have told me quote 'That part is shown in the system as being on Back Order. There are no alternative parts to order for it. Considering it is for an older Mercedes it may be months before we would receive the part."

I have told them to refund my money immediately and have politely suggested they change the way they do business.  Probably wasted 3 or 4 hours of my time including the initial phone call in the middle of the night.   Be careful of these guys if you are looking at buying part off them.  Will be interesting to see how quickly or if I get my money back.

Thomas at MBUSA has been fantastic and has put me onto the fact that the backing plate was also used on 220b, 220Sb, 220SEb, 230S also have the same part. 1964-1967.   So I am off to a couple of breaking yards in the upcoming days to see what I can find.  I am picking the 230s is my best chance here.

Am sure the problem will resolve itself one way or another.

[andyburns]

Starting the assembly of the axle tubes today.  Worked on the fixed axle as it by far the simpler of the two to install.  All went well.  Spent ages cleaning the flanges to ensure the best possible seal.  Used wax and grease remover before I applied the sealant to both flanges.  I do not want this to leak and have to pull it apart again so hopefully this attention to detail will sort this issue out once and for all.

Applied a very thin smear of bearing grease to the bearing running surface in the tube.  I dont know how long it will be before the diff is refilled so this should protect the surface from surface rust.

Before I started the whole process I thoroughly cleaned the inside of the tube.  Even though I cleaned out the tube prior to bead blasting there was still residual oil present inside the tube which attracted and soaked up a good layer of blast media.  This stuff is not what you want in any internal car part.  Would quickly mix with the oil and get transported into moving parts and seals, accelerating any natural wear.  I learnt this lesson the hard way with work I had outsourced.

[andyburns]

Also working on the swing arm shaft installation order.  I got really really confused when looking at the mercedes parts break down schematics.  They just dont have enough details to accurately identify bits and pieces.  Also the breakdown I have seems to have more parts than I took off.  

In the end I have just applied some common sense looking at what moves and where the grease is suppose to be retained.   If anyone thinks I have mucked up the order please sing out.

I also am having problems figuring out the orientation of the main clunk bush in the carrier arm.  Its not symmetrical and must go in the carrier arm in a certain way.

[andyburns]

Rodger has done it again and created yet another superb machined tool to help with the axle refit.  This time he has put his considerable talent towards creating a tightening tool for the large slotted nut that holds the wheel bearing tight on the axle.  The bearing is torqued to 20mkp or around 200nm which is really quite tight.  Without the tool I would not be able to achieve this.   

He has taken my spare nut and made a mirror image impression on his lathe and then machined out the side relative to where the slots are and then welded in two pieces of square steel that exactly match the slot.  After which the new tool has been welded to a long piece of round steel with a large torquing nut welded to the top.  Hey presto 200nm here I come.

As soon as I have sourced a new backing plate I will gratefully put this little sucker into use.  So once again a big thanks goes out to Rodger and his exceptional engineering talents.  As the younger generation often seem to say.. 'You Rock'



 

[rutger kohler]

Hi Andy, happy to help,  I might need it myself one day.  Just to let the rest of the world know I do have more sophisticated vices in my workshop but the old blacksmiths vice in the photo is ideal for all my welding etc.

[andyburns]

Rodger, don't know why your embarrassed about your vice.  As the old adage goes its not how big it is, its how you use it! 

 

[andyburns]

Decided to proceed with my diff arm refit this morning.  Was quite unsure of exactly what I am doing but just needed to push on.  I didn't have any special tools to help slide everything but just decided to give it a crack and see where it would take me.

I was pleasantly surprised at how easy it was.  The biggest issue I had was sliding in and aligning the two copper washers as the rubber o rings obscured them from view all the time.  Got around this by hooking up the o rings on the grease nipple.  This one simple technique made everything so much easier. 

The two coppers washers were slightly different thicknesses.   One was 1.85mm and the other 2.15.  I spent ages deliberating which one went where and finally decided the thinner one should go on the rear of the diff which effectively tightened up the tolerances between the clunk bush and the either end of its mating surfaces.  Dont know if this is correct but at the end of the day we are only talking .3 of a mm so hopefully the diff wont fly apart any sort of catastrophic manner.

I didn't need to replace any of the copper bushes so the pin slid all the way through aided with a thin smear of grease.  The central wedge pin which seats up against a machined flat surface on the main pin went strait back in as well.

Another problem which has been thwarting me resolved itself pretty much on it own.  The new clunk bush is aftermarket and bore no obvious markings that are present on the OEM parts.  I think there are normally the word uben indicating which way up the eccentric bush is aligned.

On the front end of the aftermarket bush there is a strike mark.  The first time I saw it I thought it look so much like transport damage or a manufacturer defect that I queried the supplier.  He picked up a number of them and confirmed that they all bore the same crude mark.

Once I slipped the central swing arm pin through the clunk bush it all became apparent.  This mark lines up with the slot in the swing arm pin and orients the thickest part of the rubber in the bush to lowest position on the car.

All in all a satisfying morning.  Just waiting for another final load of plated nuts and bolts and the big reinstall will take place.

 

[andyburns]

Spent all morning at Startech Enterprises, a parts place here in Auckland specializing in all things Mercedes.  I was extracting a backing plate from an early finny rear end to replace my damaged item.  Was a bit of a nightmare as I had to work amongst several tightly packed pellets of miscellaneous diff and suspension parts.  Of course the pellet I was interested in was slap dab in the middle and my diff of interest was at the bottom.

Took a good hour crouched in all sort of weird positions and the axle slipped out.  Certainly helped that I had a bit of practice on my car.  I think I am rapidly getting too old to do this sort of stuff.  The body is screaming this afternoon. 

With the axle on the bench I put Rodgers awesome tools to good use and made quick work of getting the slotted nut off and the bearing pulled off its journal.  Quickly degreased the plate, paint stripped and then into the blaster.

Painted up this afternoon.  Looking forward to seeing the tail end of this diff.  After reading this BBB again last night I suspect I may have to drop the main axle pivot pin and change the orientation of the two brass washers.  The  BBB makes reference to these washers butting up against the non chamfered edge of the steel tubed that run on the brass bushes.  A bit more investigation.   Pretty pissed as I have finished setting up and it pretty much ready to be installed.

The joys!

 

[andyburns]

Decided to tackle my pinion seal prior to putting the diff back in the car.  I am also taking the stance that it was probably correct to begin with.  Mark and take measurements to put the nut back in the same position.  I have read all about how difficult it is to set up if you loose the original setting.  Not something I want to entertain at this point.

I have counted the visible threads on the shaft, marked the position of the nut relative to the shaft and measured the depth of the castle cut outs relative to the top of the shaft.  Am confident I will get it back within cooee

The old seal was a bit of a mongrel to get off.  I eventually collapsed it with a screwdriver carefully hammering the outer lip toward the shaft until the seal imploded.

[andyburns]

I would appreciate some advice about the locking tab cage.  When I took the nut off I could not see any form of locking to ensure the nut wouldn't move once nipped up.  I am assuming the nut is pinched down on the surrounding thin cage and then the well of the cage is collapsed into the nut castle cutouts after the desired torque is achieved.

If I am wrong on this one I would appreciate if someone could put me right.  A good photo of how it is suppose to be would be awesome as well.

Also having problems finding a pipe the right size to push the seal in with.  I am picking an socket between 50 to 60mm would do the job.  Just cant find something lying around thats the correct size.  I did have a very very expensive oversize 3/4 inch drive socket set that went up to 60 or 70mm from memory.   I lent out a couple of years ago to a 'friend'.  It never came back and I cant remember who I lent it to.   Could have done with it this afternoon. Anyone got any good ideas about an improvised tool?

[GGR]

You need to pinch the nut cage in the slot in the flange visible in the first picture of your post No 633, kind of at 8 o'clock. Your cage has a missing part, seen at 12 o'clock in your first picture above. That means your nut was undone before as that part was pinched in the flange slot before it was cut away when the nut was undone. If the cage is tight with the nut it also means the nut was not put back in its original position as this missing part was not matching the slot in the flange. So taking note of where the nut was is only good to put it back where the previous mechanic put it. Now, did he torque it as per specifications, is your guess.

[andyburns]

Thanks GGR that all makes perfect sense including your comments about the last mechanic.

[Tomnistuff]

Andy,

Regarding installing seals, my best friends are my local hardware store and a scale or calipers.  I almost always find a PVC coupling for about a dollar that is the right size to drive in a seal with a block of wood on the opposite end.  If there's a shaft in place, sometimes it takes a piece of PVC pipe of the appropriate length.  Longer makes it easier to keep it in line with the seal bore too.

Tom Kizer

[andyburns]

Thanks Tom that sounds like a good plan to me.  I had never thought of using plastic.  I suppose come to think about it not much force is required so it should be fine.  Love it.  Thanks for the tip.

[Naj ✝︎]

I would appreciate some advice about the locking tab cage.  When I took the nut off I could not see any form of locking to ensure the nut wouldn't move once nipped up.  I am assuming the nut is pinched down on the surrounding thin cage and then the well of the cage is collapsed into the nut castle cutouts after the desired torque is achieved.

If I am wrong on this one I would appreciate if someone could put me right.  A good photo of how it is suppose to be would be awesome as well.

Here's an original

[rutger kohler]

Andy, I made a tool up for this and have it here if you want.  Ring me fist to make sure i am home.

cheers

Rodger

[andyburns]

Big Day...  pulled apart diff pivot arm pin again and changed the orientation of the two brass washers.  Reassembled and then pushed in the new pinion seal.  I ended up using a large piece of 60mm pipe.   Set up the support arm as per the BBB.  Installed the new main hanger rubber bush then decided to haul the diff under the car on an old sleeping bag and try and use the jack to hoist it into position.  Had difficulties with the diff falling off the jack and ending up using rope to tie everything in place.  With foot pumping the trolly jack after about 4 attempts I managed to get it into the right position and it popped through the main hanger bush in the boot.  Got a bit hairy at this point as I had to wedge the diff on the body so I could get out from under the car and put the bolt in.  I only had a set of axle jacks holding the whole back of the car up and when I cranked the diff it start to rock a bit... so a bit naughty on my behalf.  Dont recommend this practice.

End result was what I am after.. one new sparkly diff in place and ready to receive newly painted axles and backing plates.

I used Rodgers swanky support arm alignment tool.  It worked well but if we ever make a mark II I would recommend that the OD of the tool as it butts up to is  slightly to narrow as 'stepped lip' is created which tends to roll the edge of the rubber as it starts to get pressed off the tool.  I made a couple of subtle modifications to the tool (sorry Rodger promise they are for the better) and with a little bit of plumbers grease both the rubbers located.  Couldn't have done it without the tool so a big shout out to Rodger.  You should manufacture and sell these little puppies Rodger!  There would be hundreds of Mercedes workshops and private owners that could benefit.

So there you have it.  One happy punter.  The diff has been a really arduous endeavor and physically seeing it back in the car is a huge psychological milestone.  Well chuffed.

[Garry]

That looks a great job Andy, well done.  I have not had the dif out on my 230SL and only did a full swap in my 280SL for a 3.69 ratio many years ago. Probably all beyond me now

Garry

[andyburns]

Garry I am almost certain the job was beyond me as well.  Have no idea how I pulled it off.  My body feels like its been pulverized with a huge meat cleaver.  I am almost certain this will be the last car I am capable of doing. 

Still need to pick up the last load of silver and gold plating and do the final fit up.  I am **** scared the large round clamps that hold down the big rubber boot cant be put on 'afterwards'  and I will have to pull out the entire diff and pull the main swing arm pin.... again.  Imagine that!

[mbzse]

.../... scared the large round clamps that hold down the big rubber boot cant be put on 'afterwards'

You can be assured about putting the clamps on . The present day method is to use 9mm wide band and large type split roll pins, available from M-B or other vendors. You can mount these clamps with ease on your rear axle when assembled.

From factory, the special Beru toggle type clamp hardware S9 N was used. This is no longer in the EPC, and to source it today is somewhat expensive. See this thread, reply #6,  9 and 10
http://www.sl113.org/forums/index.php?topic=19920.25
Picture is below
/Hans in Sweden

[andyburns]

Hey Hans,  the bands on it were what it shipped from the factory with.  I have restored these.  Are you saying I shouldn't put them back on?  I can imagine they cause quite a bit of the 'leakage' issues. 

[andyburns]

Hans,  thanks for the photo.  I have the same early Beru toggle clamps.  So hopefully this can be pulled apart and hooked over the diff.  The BBB specifies that they are put on while your assembling the swing arm.  I couldn't find any other reference to them being installed after the event which made me a little nervous as I dont currently have the clips and cant remember exactly how they work.  Pretty confident it should be ok.  I read your thread about 4 or 5 times during my rebuild.  It really helped so thanks

[mbzse]

../... I have restored these.  Are you saying I shouldn't put them back on?.../...

You determine. Usually the bands are corroded so one puts fresh band metal on, the 5 or 9mm wide bands are bought in rolls so low cost.
See Gemi instruction sketch B for how band is looped
/Hans in Sweden
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