Centering differential Mount - How?

[PeterW113]

Hello all and Happy New year!

Having completed flushing and bleeding my brakes after fitting a new master cylinder, whilst the rear of the car was still on axel stands I thought I would replace the Differential mount as this had been flagged as being in need of replacement.

With the help of this thread:

https://www.sl113.org/forums/index.php?topic=806.msg3842#msg3842

I thought I would give it a go.

Progress was moving ahead in the right direction until i tried to unbolt and remove the mount itself. Whilst with some force I can rotate the mount by hand, I just cannot get it to release from the diff carrier as it seems to jam on the body work.

I put this down to two possibilities -

1) The diff carrier is not centred correctly as the mount is clearly off to one side.
2) A build up of rust on the carrier is preventing the mount from separating from the carrier.

To illustrate with the use of a clock face, 12,00 being the front of the car and 6.00 the rear, the diff mount is off centre in the 9.00 direction preventing the bottom of the mount clearing the hole and releasing.



I am using a trolley jack to support the diff but I just cannot get the diff to move in the 3.00 direction to centre the diff.

I was wondering:

If I am doing something fundamentally wrong.

or is the a better position to place the trolly each so the diff carrier will move towards 3.00 / centre position.

I look forward to any suggestions.

Many thanks

Peter

[PeterW113]

I managed to centre the differential carrier by using a strap.

Job done, my approach may not be conventional but worked and may help others who tackle this job.


Peter

[Pawel66]

Peter, I am sorry, maybe it is a stupid remark from me, but this trunk matt looks like an original - very rare these days and expensive if I remember correctly... You may want to save it...
Unless I am wrong - then sorry.

[PeterW113]

Pawel,

No worries, I am pretty sure it’s original. It’s in two sections. It’s in good condition for 50 years old. The only downside is being rubber/plastic it traps moisture so yo have to keep an eye on it.

Peter

[Pawel66]

I saw it on the picture, it looked original and I thought "Gosh, you are doing some heavy stuff there (great you done it!), you might have forgotten to take the matt out and you may ruin it unintentionally as you paid attention to the serious task at hand." 

[PeterW113]

That’s a fair point, it’s easy to forget that even a boot / trunk Matt is part of the cars heritage and should be respected.

What I love about our cars is that in general, most previous owners would have just maintained their cars and not fiddled with them, so they are largely as they the factory.

A point I should make sure I remember and look after everything, including the boot Matt.😀

[enriquegarcia]

By following the thread and the ideas suggested by PeterW113, I just replaced the differential support in my '68 280SL. Just as others have described, whenever I took her out for a drive, I kept hearing unpleasant grinding/squeaking/clunking sounds coming from the rear, over my shoulder. And just as described in PeterW113's thread, a quick look in the trunk to check the differential mount revealed that the rubber was in fact collapsed, allowing metal-to-metal contact.

I got the new part from AuthenticClassics (https://www.authenticclassics.com/Rear-Axle-Mount-230SL-280SL-108-110-111-p/auth-008801.htm). Replacement was straight forward, though a bit more involved than the posted description. Removing the old mount required significant muscle and a crow bar. Inserting the new mount required a variation of PeterW113's "strap technique" to center the differential while inserting the four corner bolts. For both removal of the old and inserting of the new parts, it was helpful to jack the rear axle up and down (at the differential) while the body of the car was supported by jack stands (at the swing arm support points).

The "before and after" feel of the car is quite dramatic so the effort was well worth it. The car now rides much more smoothly, quieter, and noticeably more stable. Makes one appreciate our wonderful Pagodas all over again!

Thank you PeterW113 and all others that contributed to this thread!
-Enrique