Author Topic: Tightening torque thermostat housing 6.9  (Read 86 times)

Jan S

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Tightening torque thermostat housing 6.9
« on: 22 November 2021, 05:01 AM »
Engine M100.985 6.9

Anyone have information on the tightening torque of:

- the four M6 bolts on the thermostat cover-to-housing?
- the two M12 bolts on the thermostat housing-to-water pump?

Steel bolts and aluminum alloy threads.

Any tips would be welcomed.
1975-mod W116 450 SE with 6.9 engine

TNNBENZ

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Re: Tightening torque thermostat housing 6.9
« Reply #1 on: 22 November 2021, 08:18 AM »
     You may find info in the Forum Library.   I have the M117 service manual .  ::)
Neglected ~ Rescued ~ 1977 450SEL 4.5L  U.S.A. ver.
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rumb

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Re: Tightening torque thermostat housing 6.9
« Reply #2 on: 22 November 2021, 09:43 AM »
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

Jan S

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Re: Tightening torque thermostat housing 6.9
« Reply #3 on: 22 November 2021, 03:51 PM »
Thanks, TNNBenz, I found the tightening torque for the two M12 bolts, with 8.8 grade If I remember correctly = 23 Nm ("Thermostat housing to coolant pump bearing housing") - on page 158 in the "Manual_100-985_Mechanical_04_82.pdf".

Thanks, rumb, great table in general. However, it seems that the torques in the table you forwarded are too high compared to the workshop manual, probably due to the soft aluminum threads?

I couldn't find the torque for the four M6 bolts. Probably around 10 Nm?

1975-mod W116 450 SE with 6.9 engine