I need the torque figures for the drive belt tensioner and idler pulleys on my E220 CDI W211

Rich20

Senior Member
Joined
Jan 22, 2018
Messages
49
Reaction score
10
Your Mercedes
Mercedes e220 cdi
I need the torque figures for the drive belt tensioner and idler pulleys on my E220 CDI W211. I need the torques for the 2 bolts holding the tensioner and the bolt holding the idler pulleys. I keep hearing about people stripping the bolts. Which bolts are they talking about?
 

Droverunner

Senior Member
Joined
Aug 2, 2017
Messages
395
Reaction score
159
Location
West Cambridgeshire
Your Mercedes
2007 CLK 220 CDI Sport AMG pack.
When I changed the idlers, water pump and tensioner on our 220cdi I was happy to use the figures in Haynes as they were in line with what I expected from those fixings and a lifetime of working on cars.

Haynes say 35Nm for the central bolt on the pulleys and 25Nm for the bolts that hold the tensioner to the engine. On some forums I've seen 25Nm mentioned for the central bolt but with no source quoted.

Even if the figure of 25Nm was correct 35Nm will not strip out a bolt of this size. However when looking just now I've found forum figures as high as 68Nm for the central bolt... now that does stand a very good chance of damaging something.
 
OP
R

Rich20

Senior Member
Joined
Jan 22, 2018
Messages
49
Reaction score
10
Your Mercedes
Mercedes e220 cdi
  • Thread Starter
  • Thread starter
  • #3
Do you know if any locktite is needed on the tensioner
 

Droverunner

Senior Member
Joined
Aug 2, 2017
Messages
395
Reaction score
159
Location
West Cambridgeshire
Your Mercedes
2007 CLK 220 CDI Sport AMG pack.
I used just a dab as I could see traces of it when I took the bolts out.
 
OP
R

Rich20

Senior Member
Joined
Jan 22, 2018
Messages
49
Reaction score
10
Your Mercedes
Mercedes e220 cdi
  • Thread Starter
  • Thread starter
  • #5
I finally found the figures on wis
As far as i can see its 30nm for the 2 pully tensioner bolts and 35 nm for the 2 sheave pullys

Think i will just do them to 25nm and 30nm just in case though with some loctite

Torques.jpg
 
OP
R

Rich20

Senior Member
Joined
Jan 22, 2018
Messages
49
Reaction score
10
Your Mercedes
Mercedes e220 cdi
  • Thread Starter
  • Thread starter
  • #6
Just checked the bolt size of the tensioner, they are supposed to be m7, according to charts on the internet the torque of 30nm on wis are too much for that size bolt, I'm now confused
 

Droverunner

Senior Member
Joined
Aug 2, 2017
Messages
395
Reaction score
159
Location
West Cambridgeshire
Your Mercedes
2007 CLK 220 CDI Sport AMG pack.
Are you sure they are M7? I thought they were an external TORX socket sized E12 bolt with an M10 thread???
 
OP
R

Rich20

Senior Member
Joined
Jan 22, 2018
Messages
49
Reaction score
10
Your Mercedes
Mercedes e220 cdi
  • Thread Starter
  • Thread starter
  • #8
Just checked the 2 bolts that hold the tensioner and they have a E10 head, Tried a m8 bolt through the hole on the new tensioner - Doesnt fit so its definatly m7.
Also found a diagramon epc

Belt tensioner.jpg
The strange thing is these m7bolts, In wis apparently should be torqued to 30nm
 

Droverunner

Senior Member
Joined
Aug 2, 2017
Messages
395
Reaction score
159
Location
West Cambridgeshire
Your Mercedes
2007 CLK 220 CDI Sport AMG pack.
Ahh OK I must be misremembering these bolts as chunkier than they were if really only M7.

But I know you are trying to get this right but perhaps over thinking it a bit?

In post #5 your chart gave the torque as 30Nm... my Haynes gave it as 25Nm so same ball park. Also you could use a 1/4" drive ratchet when tightening and a firm tightening with average hand strength would be very close to the mark too, in truth not many folks would bother with a torque wrench on such routine fixings.
 
OP
R

Rich20

Senior Member
Joined
Jan 22, 2018
Messages
49
Reaction score
10
Your Mercedes
Mercedes e220 cdi
  • Thread Starter
  • Thread starter
  • #10
Finally all done. The Tensioner bolts I did them to 25nm seem ok. The idler pulleys i torqued to 35 nm- like u said not much chance or stripping them
 


Chris Knott Insurance, see oursticky posts here!
www.ckinsurance.co.uk
Top Bottom