OM606 Viscous Fan Bolt
 

Anyone know if it is hex or torx, planning on this R&R next week. I ask because PP sells a replacement torx---not too fond of them so far.

As far as I know it is hex (8mm I believe).

Yes 8mm hex. Torque to 33 ft lbs. The stubby short 8mm hex socket and pulley holder tools make this a 4 minute job.

Great I have the tools then, WP pulley holder and I used a 8mm hex wrench and cheater bar on the 603. Not 4 minutes but quick and easy. Seems I can also unbolt the rad support for more room too.

Now which clutch does not roar like a truck?;)

Definitely get the shorty 8mm hex socket bit, or you will be calling it the vicious fan coupling bolt.

The official MB one sure does, when my engine hits 82 degrees it locks in and it sounds like the engine on a garbage truck...

Replacement bolts are indeed Torx. PITA to find a tool that fits in the available space; you end up buying a whole set for one driver. Last visit to the junkyard I robbed a few cars of their hex-head bolts for my spares kit; hopefully I'll have enough to last a lifetime (mine and the car's).

Jeremy

Replacement bolts are indeed Torx. PITA to find a tool that fits in the available space; you end up buying a whole set for one driver. Last visit to the junkyard I robbed a few cars of their hex-head bolts for my spares kit; hopefully I'll have enough to last a lifetime (mine and the car's).

Jeremy

Its in and sounds like a truck!! That was actually a lot easier on the 606 than the 603. The trick is undo the rad support and voila plenty of room to work with and thankfully no vicious radiator cuts.:D 8mm allen with a cheater pipe, pulley holder and room to spare made this R&R a breeze. I think it took about 40 minutes, not counting a phone call and fixing some other things.

Now, I have hopes this will also help the AC work better by keeping the coolant temps in check. I noticed the AC seems to be definitely not as cold at around 90C vs 80C. Interestingly, temps never got above that w/o a good fan clutch even in stop and go city traffic.

Well ready for summer anyway.

Fan Bolt
 

You cannot use a hex wrench there is not enough room. I used an 8mm viking socket a 1/4" breaker bar with a deep socket in 3/8" extension. Just barely enough room to get the socket in. You can cut off a hex wrench but unless you do it is too long. Make sure the hex is all the way in the bolt is very soft and easy to bugger up. I threw mine away and bought a hard bolt to replace it.

I beg to differ, unbolting the rad. support and moving it forward provides plenty of room, more than available than on my W124. After it is loose, the bolt can be turned by hand and goes back in the same way.

Agreed, make sure the tool is in the bolt head fully so as to not strip/bugger it up.

treetops,

Did not unbolt the radiator so it was tight next time I'll try that thanks for the info. How do you move the radiator forward on a 606.910 I just went and looked at mine and there is no way I can see to unbolt the radiator support. Would like to know so I can do it next time. Sounds much much easier.

In the second photo the two bolts at the top of the picture are for the rad support there are a total of 4 unscrew them and you can pull the radiator forward. I would assume it's the same for your model.

The radiator support for a W124 is welded on, its not removable unless you wish to cut it. User JRMrie claims an OM606.910 engine - which was only installed in W124 models.

The way I remove it from a W124 with 6 cyl diesel is to first crack it loose with a regular 8mm hex key with an 8mm socket and small extension on its tail to gain leverage.

once loose

I use the little shorty socket I have to undo it all the way

to install it one has to hold it like a cigarette to push it in and then use the shorty socket to complete the threading.

Ahh, my bad. It is always helpful to have a sig that denotes from where and model(s)

x2

The bolt is just a standard metric cap screw. I forget which threads, but you could get one from boltdepot.com. Get a high grade one and use anti-seize -- I think the OEM ones have some sort of fancy coating...

Bolt
 

The bolt is M10 1.5 45mm long. I could not fit any 8mm hex wrench in there myself they would not fit needed about 1/2" cut off to fit.

Interesting. My w124 with the 603 was tough, but I got a hex key in there.

I have a made in china allen wrench set, titan branded I think, the 8mm key fits the bolt and clears the radiator fins too (best use a pizza box to save those fins)

I use the key to just crack it loose - my pulley holder is a water pump pliers which I use to hold the water pump pulley with belt on it.

After its loose I use the shorty socket to remove the bolt. You can buy this bolt from ace hardware if you want. You might need to polish off the sides of the new bolt head if its not a MB purchase.

treetops,

I got mine at Fastnal they are M10 1.5 45mm long. The ones I got were 8mm hex head. You can probably buy different heads.