Rear axle pivot shaft - how to remove wedge bolt?

[star63]

I'm trying to remove the wedge bolt that keeps the pivot shaft in place.
Any advise how to get it loose?

[mbzse]

.../... wedge bolt .../...Any advise how to get it loose?

Clean area, soak in penetrant (for some days, soak every now and then).
Remove nut, hit end of bolt with a substantial hammer/small sledge...  You can use a drift in between if you like.
/Hans in Sweden
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[star63]

Thank you, Hans.

I'm doing this without taking the axle assembly out of the car. The bolt end is behind the "fork" structure. I don't know how to hit it with a hammer (no access).

Does the bolt clear the "fork" if I lower the differential closer to the floor?

[mbzse]

..../...doing this without taking the axle assembly out of the car../...

Interesting. What task are you going to perform on your SL?
I have not done any similar thing on a 60's swing axle M-B with axle remaining mounted to the car.
/Hans in Sweden
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[Benz Dr.]

I'm not thinking that you can. I'm pretty sure you will need to drop the axle to take the hinge apart. You can remove the front cover to replace the pinion seal and I've replaced the main bushing on a 6.3 once without dropping the axle but that was only because a 6.3 has air suspension and I had more room to move the axle around. Even so it was a very tight fit going back in.

[ja17]

I like to leave the nut loose but flush with the threaded pin, so the threads are protected from hammer blows. Once the hammer blows loosen the pin, you can remove the nut the rest of the way and finish removing the pin. A soft metal hammer or hardwood rod may minimize damage to the tapered pin also. Moving the axle housing all the way up will give you a straight shot at the tapered pin.

Re-installing the axle half while the rear end is still mounted in the car will be a real challenge. Alignment of the big hinge pin, the washers, spacers, rubber seals and axle boot will be very difficult this way. It is challenging enough when out of the car. 

[star63]

Thank you all,

My plan was to change just the rubber sleeve without taking the pivot shaft out completely.

[tel76]

You can replace that rubber bush without removing the pin.
Remove prop: shaft, pinion flange, large nut at front of pin,  pinion flange seal holder (you can renew the seal whilst in there), remove strut assembly to vertical support,  place jack under axle, remove support bolt in boot, lower axle until you can move the support forward.
It is easier said than done but it is doable and you do not need to touch the clevis pin, if you attempt the job this way make sure you understand how to re-fit the pinion flange and pre-load the bearings correctly, you will find how to do this task on this site.
Have a look at the SLS rear axle page this will help you understand the above.
If I have missed something out I feel sure we will be told.

[mbzse]

.../...replace that rubber bush.../...
If I have missed something out I feel sure we will be told

Well, perhaps the matter of the longitudinal positioning of the upright support, i.e. where to clamp the rubber bushing... It is +/-1mm .
Discussed previously; see for example http://www.sl113.org/forums/index.php?topic=12503.0

Hard to measure, when axle is mounted in car.
Se for instance this thread http://www.sl113.org/forums/index.php?topic=19920.msg140662#msg140662
/Hans in Sweden
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[jameshoward]

Thank you all,

My plan was to change just the rubber sleeve without taking the pivot shaft out completely.

Just to clarify, are you referring to the axle boot (which is a rubber sleeve) or do you mean the steel and rubber bushing that folk here are talking about. If the latter, and having refurb'd my rear axle, I would suggest you remove it from the car and do the whole thing all at once. It's far easier to replace the brake lines, and other misc bits of rubber with the axle off the car and it's not a massive job if you have space and some help to mount and dismount the thing (which weighs a ton).

[star63]

I'm referring to the steel and rubber bushing.

My car made an irritating noise (not very loud) when lifting the gas pedal a little bit. I changed the rubber piece in the boot. This reduced that noise but did not totally eliminate it. I'm hoping to get rid of the remaining noise by replacing that rubber bushing.

I'd hate to drop the whole assembly down. The brake lines are already new.

[ja17]

Be sure to check out the large square mount in the trunk. This along with the two rubber bushings at the trailing arm/chassis connection are most often the source of noises.

[star63]

Thank you again!

It sounds like it would be possible to replace the steel/rubber bushing without removing the axle from the car.
Would it be possible to slide the pivot shaft rearward enough to see if the inner bushes of the slide bearings are in good enough shape?

[Benz Dr.]

I could easily become frustrated with the direction you are trying to go........... 

  Take the axle out of your car and do it properly. While you may be able to do some things that you're considering, you will end up dropping it anyway when you realize it has to come out of the car. This is hard enough to do while out of the car and impossible while in the car. You will not be able to set the pin to 90 degrees unless the axle is out.

 The main shaft will need to be removed to replace the steel bushings in the pivot which means the axle must be removed. You may be able to detect some amount of play in these bushings while the axle is still in your car but since everything will be under load, it won't be a very accurate test. If your car has a lot of miles on it I can pretty much tell you that they will be worn out.

[star63]

I lowered the differential as much as the brake hose allowed. After that it was easy to hammer the wedge pin off.
I pushed the pivot shaft rearwards for about 50 mm in order to see the condition of the rear most slide bearing.
To me it looked quite good and well greased. I might be able to measure the clearance with a feeler gage. How much should it be? (or how much is too much?)

I think I can set the pin to 90 degrees by measuring the the pin and the left axle separately with a digital clinometer.

[ja17]

Did you check the trunk mount? Your problem might be there.

[star63]

Yes Joe, the trunk mount was the first thing I checked (and replaced). It reduced the noise but did not eliminate it completely.

[ja17]

Good, replace the rubber trailing arm/chassis rubber bushings also if you have not. They are inexpensive (even from the dealer) and will also make noise. You get metal-to-metal contact, when they go bad.

[star63]

I will do that also. I have already bought the rubber doughnuts...

[Benz Dr.]

You will need to make a jig to remove the retaining clips on the trailing arms. A shop press is required.

[jameshoward]

A press is seriously helpful, but it isn't vital. A vice and a couple of bolts will achieve the same effect pretty well.

[Benz Dr.]

I used a piece of pipe about 3'' high and cut a section of it out from top to bottom so that I had clearance to pry the clip off. Removing the clips really isn't the main issue and installing them is. The new bushings will be difficult to compress and the clip is impossible to assemble unless you can compress the bushings.I can see where a vice could be used.

[ja17]

I use my home-made tool also, but I like your design better James!

[Shvegel]

I have something close to the factory tool for the press and I just did mine in the vice.

[star63]

To conclude this thread I'm proud to report that the bushing has been changed. 
This took a long time because I also installed a 5-speed Getrag and had to wait for some parts.
(Still missing a bushing for the speedo drive...)

With the great advices from you wonderful Pagoda enthusiasts the job was easier than I expected:

- I placed the car on stands
- Dropped the exhaust pipe a little lower
- Removed the horizontal spring (used Benz Doctors jack trick = very easy)
- Unbolted the center mount (the big bolt in the trunk)
- Lowered the axle as much as the brake hoses allowed
- Removed the front bearing cover of the differential
- Removed the tapered pin and (carefully) hammered the pivot shaft out about 2" to check the rear most slide bearing
- Hammered the pivot shaft back (don't damage the shaft end!), installed a new tapered pin
- Changed the bushing
- Checked the distance to the propshaft flange
- Adjusted the angle (90 deg) with a digital clinometer
- Lifted the differential back to the trunk mount
- Installed the spring
- Exhaust...
- ...done