I'm having a bit of trouble keeping the engine from turning when I try to break the bolt loose. What method did you use to lock the cam sprocket in place when loosening the bolt?

I've tried wedging various things in the sprocket, however I couldn't find a solid way of anchoring/wedging the tool on the head. I also tried having a helper apply opposite force on the crank pulley, but no luck.

Also, how hard is it to loosen the bolt? Mine seems very hard to break loose.

Am I missing something?

Page seven

I used a 1/2" drive 10" long extension through the sprocket on a 617 when I was replacing the chain guides and tensioner....worked fine. I used an impact to loosen the bolt though.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
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'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I wonder how I'm going to hold the cam still on my SD, since the sprocket disintegrated...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

In that image, there appears to be a bracket bolted to the head that allows for a good place to brace the mandrel. Is this a special tool I can buy?

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1991 300d

Use wood as a spacer if needed. I used a extension or drift pin.

Just tie-wrap the chain to the sprocket in several places, then slide a drift in there so it doesn't move, and loosen the center bolt--impact works best.