Alternator Mountings - Oil Leak??

[UKSteve]

Hi everyone,
In preparation for my summer road trip at the end of June, I'm sorting out worn V belts, disintegrated rubber bushing on the alternator mounts, and an oil leak from somewhere at the front of the block.

I've read a number of interesting posts on the forum including ones about the sneaky bolt by the chain tensioner, and this may be my problem but:

The worst of the oil appeared to be around the alternator bracket mounting studs. Are these possible culprits or has oil just accumulated there from leaks higher up?

Also, I have two empty threaded holes on the corner of the block by the alternator bracket. I guess they might be for Aircon mounts. They seem to be blind. Can anyone confirm?

Fourtunately my crank seal seems OK .

Many thanks
Steve.

[Larry & Norma]

Hi Steve, it may be helpful to say which car you have 230,250 or 280SL.

[UKSteve]

Aha, good point.

1967 230 with a 127 engine.
cheers
Steve

[Naj ✝︎]

Hi, Steve,

Oil can leak from the alternator mounting bolts.
You can remove, clean and replace with a thread sealant. Note that the bolts are short and should not be replaced with anything longer!
Not sure about the 2 other holes. Make sure they are blind.

The 'O' ring seal on the chain tensioner also hardens and leaks with age. That oil can run down the block to the alternator bracket.

Naj

[UKSteve]

Hi Naj,
Thanks for confirming my suspicion, and for the "O" ring tip.
Now for the really stupid question:

The alternator mounts are studs rather than bolts.
Is the removal process to lock on two nuts and then hope they don't buth turn when you try and extract?

Thanks
Steve

[Naj ✝︎]

Hi, Steve,

Yes, I'm sure the two nut method would work.

Check the alternator bracket thoroughly for any cracks.
I've heard a few stories of the 230 bracket breaking on long trips.
The new rubber mounting bushes will help too.

Naj

[al_lieffring]

Also check the bolt hidden inside the timing chain tensioner well. This is a 6mm bolt (5mm allen) inside the timing chain well where the head bolts to the front of the block. one of these bolts is hidden inside the pool of oil that feeds the chain tensioner, and this hole is drilled through the block and comes out behind the water pump housing and will make oil drip appear to be dripping from the right front corner of the block.