How to change Harmonic Balancer (crankshaft pulley) V6 petrol

[stargazerplus]

Maybe I was lucky but I found this easy... and it is supposed to be a difficult job, requiring a Merc special tool which costs a lot. I did have to go out and buy a couple of bits and pieces but at £40 was a lot less than the labour.

Tools required, two foot breaker bar, 17mm hex key, 5mm allen key, screwdriver, cold chisel, jemmy bar, 15mm ring spanner.

Remove radiator shroud clips with screwdriver and lift shroud out.

Remove 3 allen bolts holding fan to viscous coupling.

Remove poly belt. The tensioner is supposed to be turned anticlockwise using a torx socket but I found that a 15mm ring spanner on the tensioner pulley bolt did the same job.

Now you have access to the crankshaft pulley. Put the 17mm allen socket into the bolt and wedge the pulley with the cold chisel and the jemmy (this is where you are supposed to use the MB special tool) and heave on the breaker bar. Bolt came free on first tug. I protected the radiator with a sheet of ply in case of flying tools.

Pulley comes off with some very gentle prying. Replacement is reverse of removal. Took less than an hour all in.

I just didn't believe this would be so easy, as these are supposed to be a b***er to remove. Halfords sell the tools apart from the 17mm hex but I used a Laser hex key with 19mm body and a 19mm socket on the breaker bar.

 

[grober]

Stretch bolt???

Well done-job well done. Did see this on the MERCEDES SHOP site courtesy of a DR DIESEL but I'm sure its not strictly necessary.
Like most MB engine bolts, the crank bolt uses a stretch shank and
has a maximum service measurement. when you are dealing with torques of around 400+NM, I tend to replace these things.
Just like steering wheel bolts, why chance it to save $4?
Make sure your guy uses the correct balancer counter holding tool! If not, and he uses a flywheel lock or ring gear cheater,
you can bend or even break these crankshafts.
It takes the correct tool to hold these when loosening and torquing. PN# 112 589 00 40 00.
The torque is very important also.
step 1 ----- 200nm
step 2 ----- 95 degree angle of rotation.

 

[stargazerplus]

Managed to hold the pulley quite adequately! I actually did replace the bolt which has loctite on the threads. New bolt is 27mm head and not 17mm hex.

 

[grober]

On the plus side.

Glad to hear it. Its ironic that items failing early in the life of a car are usually easily replaced because corrosion or thermal creep hasnt locked them solid!! Its the one positive aspect of components with poor longevity. Hope the next one lasts a bit longer.