Torque Setting.

[Mike Heagney]

Thanks for your reply on the licence lenses Bob.
Can someone advise the torque setting for the socket head screws which hold the alloy crank case to the bottm of the block ?
The workshop manual is not telling me !
Thanks,
Mike.
 64 230 SL. rhd auto....in boxes.

[Ben]

I never found a reading for this either and i suspect its one of those things you do by feel. It's probably in the same region as a spark plug, nipped up but not forced.

The more experience guys here will probably either correct me or chime in later. As far as I recall there is no gasket here and a sealant is used so there isn't much to squeeze !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[Jonny B]

I will check the data manual and see if there is anything listed in there. It is at home, so it will take a day or so to get the information posted (if there is any)

Jonny B
1967 250SL Auto

[Naj ✝︎]

Hello Mike,
230SL book says 'Fastening Bolts for oil pan sheet metal sump' 0.8 mkp.
Oil pan to crankcase not mentioned as you found.

280 book says 'Fastening Bolts for oil pan sheet metal sump' 1.0 mkp
Fastening bolts oil pan to crankcase 1.3 mkp.

Hope this helps.
naj

65 230SL
68 280SL

p.s: I make 1 mkp = 7.35 ft.lbs (3.2808 feet/meter X 2.24 lb/kg)

[A Dalton]

My info shows 8.6 ft/lbs-103 in/lbs

 1 mkp = 7.233 ft/lb
 A spark plug would be 3 times as much..

[Benz Dr.]

I tighten them well and use all new hardware - always. These are socket screw so they're grade 5 in hardness. Ordinary screws are grade 3 I think. I had to remove 3 broken ones yesterday in a 220SE ( early ) engine and you can hardly drill them out. Took about an hour of careful work to get them out and not damage this very rare block. I always use a tap to chase the treads before I even start to asemble.
I use copper silicone as my sealant of choice - use can use this on exhaust pipes. THE SURFACES HAVE TO BE REALLY CLEAN with no oil or rust on them. I run a file over the surface and make sure there's no burrs or anything. I then use an angle grinder and a pad with small fingers to clean the metal. The rear seal has to be cut right and the front one should be placed on before you fit the pan.


Daniel G Caron

[Jonny B]

I checked the data book (Aug 1969)

"Mounting screws for intermediate flange at cylinder crankcase"
5 mkp (kilo pound meters) X 7.233 to convert to foot pounds.



Jonny B
1967 250SL Auto

[Benz Dr.]

I don't think that's right - in fact I know it's not. The numbers are right for the flange but this is the piece at the back of the block that sits between the bell housing and the engine. If you tightened those little screws to 36 ft lbs they's all snap off.
The oil pan screws are only 6mm screws. The other 2 at the front and back are 8mm so they could take a bit more twisting. When they get tight they stop and then continue to turn a bit as they pull a little. This when you stop turning.
This definatly a '' feel '' thing and if you break one off you find out quickly what that feels like too. Hold the ratchet close to the head so you lower the amount of tourqe you apply.

Daniel G Caron

[Jonny B]

Benz Dr. thanks for the clarification. I did double check the data manual last night, and there is no other listing for the engine crankcase screws.

I re-checked the verbiage I had in quotes, and that was correct (from the data manual that is)and it was the same setting for the whole range of cars in the period of the 60's.

Proving once again the power of having many eyes looking at the information.

Jonny B
1967 250SL Auto