Author Topic: Gearbox seals??  (Read 280 times)

Greasyone

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  • Australia, New South Wales, Sydney
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Gearbox seals??
« on: December 22, 2019, 00:51:20 »
Hi everyone! I'm new to this forum. I've owned and maintained several Mercedes including a 1960 220SEb W111 assembled in Australia.

I have the manual transmission/gearbox out to inspect and replace leaking seals.

How do you insert this type of seal without damage?? Picture attached.

Thanks!

Benz Dr.

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  • Canada, ON, Port Lambton
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  • Benz Dr.
Re: Gearbox seals??
« Reply #1 on: December 22, 2019, 03:50:31 »
You need a special installing tool or you will never get it to install correctly. I made my own on a lathe. I'll measure mine and post the sizes later this week.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

ja17

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  • USA, OH, Blacklick
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Re: Gearbox seals??
« Reply #2 on: December 22, 2019, 05:54:51 »
In my case I found a hole-saw, just the right size.  I ground the teeth off the hole saw so it was flat, then used it to drive the seal in place. Worked just fine.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Greasyone

  • Junior Level
  • Australia, New South Wales, Sydney
  • Posts: 6
Re: Gearbox seals??
« Reply #3 on: December 22, 2019, 16:47:49 »
Hole-saw is a good idea. Will investigate.

The small one is for the speedometer drive. The old one did not want to come out easily! Even with heat, we had to use far more pressure to drive it out than I was comfortable with! The thought of cracking the alloy cover....

Greasyone

  • Junior Level
  • Australia, New South Wales, Sydney
  • Posts: 6
Re: Gearbox seals??
« Reply #4 on: December 22, 2019, 16:55:31 »
Found this very informative gearbox schematic on a Ponton website. It's a Daimler Benz training aid. Someone spent many hours putting it together!

Greasyone

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  • Australia, New South Wales, Sydney
  • Posts: 6
Re: Gearbox seals??
« Reply #5 on: December 24, 2019, 04:34:07 »
Following up on your suggestions, my son showed the seal to a machinist at his work who effortlessly made up a brass tool which worked well to drive it in.

For future reference, the tool measures 34.8 mm OD, 32.8 mm ID and 22 mm deep.
Pictures attached.

Benz Dr.

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Re: Gearbox seals??
« Reply #6 on: December 25, 2019, 00:24:47 »
I use a drill a bit smaller than the OD of the speedo seal. There is a void inside the casting with a shoulder in front of it so that the seal will only go into the casting up to the shoulder. After I drilled through the old seal I found that I could easily pick out what was left of the outer shell of the old seal.  The void in the casting is designed so that the shaft that drives the speedometer will expand the seal slightly as it slides through the seal when it's installed. This void is needed so that the seal can expand and stay tight against the shaft.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn