Help please with stuck fan bolts - PeachParts Mercedes-Benz Forum

blueriomedina · #1 03-14-2011, 01:12 AM

I need to change my serpentine belt, belt tensioner and tensioner shock but two of the three bolts to the fan they are stuck hate to say it they are strip I just can get them out.

If anyone has, any ideas on how to get these two bolts out I will really appreciate your help

I am also doing the engine mounts (which I will post some pictures) but that has been a relative easy job compare with the fan bolts

Oscar

sptt · #2 03-14-2011, 01:47 AM

I had the same issue and they all stripped out on me as well. You can turn it over and try to drill them out but I ended up buying a new fan clutch and got the fan off Ebay for $25.00 ($45 to $100 everywhere else). I have no idea why they are in so tight like that! Good luck.

engatwork · #3 03-14-2011, 07:35 AM

Are you trying to remove the three small allen head fasteners? If you remove those you still won't get the fan off. You have to remove the large allen head fastener in the center of the fan to get the complete assembly off and then you should be able to drill the small allen head fasteners out to remove them.

sptt · #4 03-14-2011, 09:19 AM

Oh yes....I didn't look at the picture close enough to see that it is still in on the engine. You have to get the fan clutch/ assembly out first...sorry. You may need the pulley lock tool to lock the pulley from spinning when you turn the allen head bolt (counterclockwise) depending upon the year.

Duner · #5 03-14-2011, 10:11 AM

This are notes for myself to remove fan. I have early M103 with one piece fan shroud. Finding the magic hole was fun. There are fotos in the archives so you can see what you are looking for.

MB front of engine access
#1 remove 2 clips holding 1 piece shroud at top with cotter pin tool.
#2 19 mm ½" socket with adapter to 3/8" and breaker bar to loosen

auxiliary drive belt bolt tensioner .
#3 Back off tensioner adjusting nut to remove auxiliary drive belt.
#4 Use special tool to find "magic hole " in fan hub to hold it from turning.
#5 8mm allen wrench in center of fan viscous coupling to remove fan and fan hub assembly.

#6 Fan shroud can now be removed.

sptt · #6 03-15-2011, 12:45 AM

So...I took mine out after finding the magic hole and could still not get the bolts out to remove the fan. I threw it away. It was so akward to hold while trying that I finally gave up and bought new parts.

JohnM. · #7 03-15-2011, 01:06 AM

My "magic hole" tool is a valve cover bale from an aircooled volkswagen engine, one of the ends is bent. But the diameter of the bale is perfect to fit the hole. I've used it many times to remove the fan clutch.

The early one piece fan shroud is a real b!tch, requiring removal of fan before shroud removal. The later (90-up) two piece plastic shroud is much better design and doesn't require the fan to be removed.

EricSilver · #8 03-15-2011, 08:51 AM

Go to Sears, get the $19 Bolt-Out set, problem solved.

tilac1 · #9 03-15-2011, 06:17 PM

I had the same problem on my '88 300E. I used a wizz-wheel (cut-off wheel) to slot the stripped allen head bolt and then a flat-blade screwdriver to remove. I also used the wizz-wheel to divide the shroud into two halves and siliconed it back together afterwards.

sptt · #10 03-15-2011, 08:35 PM

Tried the Sears "Bolt Out" and it did not work. Problem not solved...at least with me. Returned it.

EricSilver · #11 03-15-2011, 08:46 PM

Quote:

Originally Posted by sptt

Tried the Sears "Bolt Out" and it did not work. Problem not solved...at least with me. Returned it.

The trick with the bolt-out to to either 1) come at the bolt pressing hard from an angle; or 2) tapping it with a hammer or mallet. The goal is to get the helical ridges to bite into the bolt a bit. Once they do, it's coming off.

JohnM. · #12 03-15-2011, 10:07 PM

Also, if the bolt is already trashed, I've had luck using a slightly bigger "star" or "torx" bit than the allen head that is stripped. That sometimes gives enough bite to break it loose.

blueriomedina · #13 03-16-2011, 11:53 AM

Thanks to all for the comments,

I am still working on this, actually today I will attempt get the bolts out, and will be following some of the suggestions.

Changed both of the motor mounts and that job seem like a piece of cake compare with these two stuck bolts, amazing

Once again thanks and I will let you all know of the outcome

Oscar
1995 E-320 167,000