Mercedes-Benz Forum banner

1 - 13 of 13 Posts

·
Registered
1979 450SL
Joined
·
156 Posts
Discussion Starter #1
I have the factory service manuals and am surprised by the lack of torque specs listed for various fasteners (like the water pump bolts among other things). Raised in Porsche-land, where there is a spec for everything, I default to using 7 ft lbs on M6 bolts, 15 ft lbs on M8 bolts and 33 ft lbs for M10 bolts, assuming normal 8.8 fasteners, unless otherwise specified. Does Mercedes assume/default to these values as well (or others)? Even the dreaded Haynes manual seems to only publish very few torque specs and says, for example, to tighten the water pump bolts "securely"... Am I missing it, or does Mercedes just not publish many torque specs?
 

·
Premium Member
1983 380SL, 2000 S430, 1991 420SEL (retired) - RHD
Joined
·
5,194 Posts
My manuals give the torque for tightening bolts within each particular job description. The 450 iron motor would not be as sensitive as the alloy motors?
 

·
Outstanding Contributor , Bob's Your Uncle!
-----'83 280 SL----- 5 speed....The PIG
Joined
·
29,192 Posts
My manuals give the torque for tightening bolts within each particular job description.
Same....beginning of the section gives the torque specs and special tool requirements.
 

·
Registered
1979 450SL
Joined
·
156 Posts
Discussion Starter #4
Yes, I have the factory manuals (full print versions) and am just surprised by how few torque specs it gives. For replacing the water pump, for example, the only torque spec it gives is for the radiator drain plug. Maybe Porsche is more paranoid due to all the aluminum as you say. If you still think I'm missing the torque specs somehow, please point me to them and/or tell me what you see for the water pump bolts...
 

·
Premium Member
1983 380SL, 2000 S430, 1991 420SEL (retired) - RHD
Joined
·
5,194 Posts
Torque for water pump.

Yes, I have the factory manuals (full print versions) and am just surprised by how few torque specs it gives. For replacing the water pump, for example, the only torque spec it gives is for the radiator drain plug. Maybe Porsche is more paranoid due to all the aluminum as you say. If you still think I'm missing the torque specs somehow, please point me to them and/or tell me what you see for the water pump bolts...
My manual only shows torque for assembly of the pump itself, not the actual bolts holding the pump to the block.
 

·
Registered
1979 450SL
Joined
·
156 Posts
Discussion Starter #6
My manual only shows torque for assembly of the pump itself, not the actual bolts holding the pump to the block.
ok, thanks, just wanted to make sure I wasn't missing the torque spec volume or something. I saw the impeller torque spec and see a few others sprinkled throughout the various procedures, so guess that's all MB thought worth specifying. Porsche give you a torque spec for turning up the radio volume practically, so it's almost refreshing to see MB rely on common sense.
 

·
Outstanding Contributor , Bob's Your Uncle!
-----'83 280 SL----- 5 speed....The PIG
Joined
·
29,192 Posts
The only thing that I've used a torque wrench for is the spark plugs! Steel plugs in an aluminum head.

I should also add, that I've never had the heads off....I would use a torque spec for that, as well. Everything else is just by "mechanic's feel".

1 grunt or more. :)
 

·
Registered
1978 450SL
Joined
·
333 Posts
Having the same issues with torque ??. Installing the water pump tomorrow. Fingers crossed. Today was scheduled to install but the water heater decided to over flow the pan & we had water everywhere. All of the bolts I have for water pump are 8.8 different lengths, the 3 that hold the tStat housing to the water pump are 8.8 1" long & the 4 that hold the viscous fan on are 8.8. Any thoughts on torque? I may just tighten as "securely" as I remember them being when I took it off. Thanks, TB
 

·
Registered
1985 380 SL
Joined
·
49 Posts
Here is an excerpt from the internal company standard that we used for our industrial diesel engines. Most fasteners fell under class III, this would apply to things like water pumps, intake manifolds, valve covers, brackets, and the like. These are general recommendations, the class II and III apply regardless of the material. Class I is a recommended "check torque" when using a calculated angle rotation tightening method.

2617044
 
1 - 13 of 13 Posts
Top