Diffrential crown nut torque tool

[mbzse]

In order to loosen the crown nut on the diffrential, most often with the purpose of exchanging the seal for the pinion shaft,
there is a special M-B tool. However, hard to get hold of. People have often resorted to using a hammer and chisel to loosen (and tighten) this crown nut.
Now there is a tool which can be bought that fits, vendor is company Rahmenschmiede in Germany
http://www.rahmenschmiede.de/
Tool needed is "Werkzeug Kupplung Honda CB 750/900/1100 F & R"  See picture 1.  You can also find this tool for sale on e-Bay, item 1130399183809
Note: I have no affiliation with seller

Here is how I work with this:. Due to the rather high torque needed to loosen or tighten the crown nut for the pinion, the nut tool easily slips off, hard to govern.
I have made a device to hold the crown nut remover tool in position during the torque manouver.
A pipe some 60cm (2 feet) then gives ample strength on the 19mm hex for loosening the crown nut. (picture 1)

In picture 2 the parts are at work, the silver metal bar you see is attached with a M10 bolt and anchors the flange, to prevent it from rotating.
With this method you can apply a rather precise torque when tightening the crown nut

Picture 3 shows the crown nut that anchors the diff flange onto the pinion shaft (borrowed picture)

/Hans in Sweden

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[IXLR8]

Thanks, Hans.

Great tip and pictures.

I suggest that this be posted in the WIKI.


Joe

[don p]

I have removed the Crown nut using Hans method.  Now having trouble getting the pinion flange off to get to the seal. what is the best way to remove the flange?

[George Des]

Hans,

That pin socket is readily available through  Samstag Tools and some others as well. I bought one for about $50.00 US sometime ago when I did my pinion seal. The real tricky part of this seal replacement is getting the correct pinion bearing pre-load. There are all sorts of tricks to getting it "near" correct, but my guess is once the original pre-load is released all you can hope for is to get it close without overdoing it and deforming the crush sleeve that sits between the two bearings. The only thing you can do at that point if you go too far is to replace the sleeve and that means a very laborious teardown of the entire axle to get at it.  I've torn apart two 230SL axles and it isn't much fun!

George

[Benz Dr.]

I use an impact gun to remove the nut - zips them off easily. I mark the position before removal and put it back to the same place. This usually works because you're duplicating an original position.
Once you distrurb the crown an pinion, you're in deep do do. I leave that stuff alone or start looking for another axle ( seriously folks ). Unless you can find someone with the tools and know how to set it up properly, you might play with it for a long time and never get it right again.

[don p]

I marked the nut and pinion shaft before removing it but having a hard time removing the pinion flange to get to the oil seal. Is a  puller reguired to remove  it?

[George Des]

Don,

I don't recall having too much trouble pulling the flange. You may be able to find a piece of angle iron you can drill and bolt on to the flange so you can give it some light raps with a hammer--the angle iron not the flange0hitting on one side then rotating 180 degrees to hit it again on the other side--same method some people use to pull the axle shafts from the tubes. I think Joe Alexander has a post here that shows how he does that. Also, some slide hammers have an attachment you may be able to bolt onto the flange to coax it off. I'd coat the area with something like PB Blaster too. Hope this helps.

George