Tensioner Pulley Allen Wrench?
 

I've looked around the forum, on google, in my manual, and I can't seem to get the answer I need.

I noticed today that the assembly that holds the tensioner pulley looks like it may need to be tightened. It's possible the bearings are just worn, and it needs to be replaced. It uses a pretty big allen wrench, bigger then anything I have. Does anyone know the exact size so I can pick one up when I go to town again?

It doesn't seem to be affecting the belt at all even though it's at an angle. It's not squealing or looking worn on one side of the belt. I even accelerated and watched it to see if anything looked really bad, and it's riding okay for now.

I know it needs to be looked at, but I need the allen wrench to try to tighten it, and even pull it off later if it needs to be replaced.

The biggest allen wrench I have, I use for changing the brakes out on the front of Chevy's. It's no where close to the size I need.

10mm

Thanks a lot for the fast response I just called a friend and he said he has one so I'll do that instead of buying one.

I guess I should have mentioned it's for an 86 Mercedes 300SDL because 10MM is not the right size I'm glad I didn't go buy one. I tried a 10MM and a 12MM and 12 was too big so I guess it's an 11MM. My buddy didn't have an 11 for me to try so I dunno.

Mine was 12 on my 603,but if yours is actually 11mm a 7/16 sae one should work. Don

Well a 12MM was just a little bit too big it wouldn't fit. 10MM seemed to be way too small. Only other guess is 11MM. Only problem with SAE is hardly anyone has those. Everyone has the Metric ones.

12mm is what it should be, nothing else.

I got mine here

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=98229

I picked up a 12 and 10 from a buddy just today and the 12 was a little too big. It wouldn't go into the hex slot.

For anyone planning work... good ol' ebay sure can be good. I picked up the needed 14mm for the differential plugs and several others in one listing for about $6 delivered. Most supply houses want around $10 for just the 14mm.

I can't really wait for shipping and all that. This is my only vehicle at the moment. Not my only one but the only one registered and legal to drive. Waiting for something to take three to four business days to get to me is just not an option. I'll just have to pay when I get to town today. I'll just buy a few different sizes I need some big allen wrenches anyways.

The 12 point tool for the head bolts has 12mm shank and thats what i used to take the belt tensioner off with. Its pretty long so only would work with the radiator out,if you happen to have one of those give it a try. Don

I was able to borrow another 12MM from the same friend and I guess the one he had before wasn't any good. It wouldn't fit but this one slide right in so it is 12MM. It was as tight as can be. So I guess the bearings are no good that's just my luck. When I'm broke things keep breaking lol.

I even tried to loosen it and it is extremely tight. I will have to put a breaker bar on it when I do finally replace it.