88 300CE serpentine belt tensioner - PeachParts Mercedes-Benz Forum

Kyle Blackmore · #1 11-16-2002, 03:08 PM

I'm in the middle of replacing the drive belt and I believe the tensioner is hooped.The pointer is 180 degrees out and doesn't seem to move when I tighten up the 13 mm adjusting belt.The belt seems as tight as it was before but....To remove the belt I tried unsuccessfully to remove the fan,the wrench just kept slipping off

,so I pulled the rad

,now before I put it back together I'm wondering is there any MM fixes I can do to make it last a little longer.I'm going to try the fan bolt again now that I have a little more room,but what a PITA!!

Mick J · #2 11-16-2002, 04:45 PM

Did you loosen the big (17mm?) bolt that goes through the centre of the tensioner first? If not you probably broke the adjusting rod.

Correct tightening procedure is to turn the pointer to the zero end of the scale then tighten the adjuster until it aligns with the mark.

Kyle Blackmore · #3 11-16-2002, 07:41 PM

Thanks Mick,yes I did it correctly,loosening the 19mm bolt first,then turning the 13mm hollow bolt.Before I took it apart though,the pointer wasn't there.The inner and outer parts of the tensioner have spun as far as I can figure.
I still couldn't loosen the fan bolt,that bolt was already stripped out a bit and I wasn't going to totally ruin it.I know a trick for stripped screw heads is to put a little valve grinding compound on the screwdriver,next time maybe I'll try that on the allen key.

Gilly · #4 11-16-2002, 10:54 PM

Kyle:
If you still need to remove the central bolt for the fan, what I do if the bolt head is stripped is use a Torx socket instead of an allen, there is one size that you need to tap in to the head, and it works great. I think it's a T47 or T50 torx, hasn't failed me yet. I assume you have something inserted into the fan pulley to hold it locked. Be sure to get a replacement bolt for the fan, and it's supposed to be torqued to 40 nm.

Gilly

Kyle Blackmore · #5 11-17-2002, 12:22 PM

Thanks Gilly,good tip, i'll have to try that.I have it all together now and the belt seems tight and quiet,now onto the 123 for belts(I know the Turtle will be easier,except that bolt that rattled off the A/C compressor).I'll look into a tensioner for it next week,any other parts I should do while it's apart again?

Gilly · #6 11-17-2002, 02:56 PM

Kyle:
The tensioner itself and lots of times the small shock absorber is worn out too, the eyelets and the end loosen up. Possibly, as someone mentioned earlier, you may have broken the threaded rod that operates the tensioner, unless you know this to be false.
Also the central bolt for the fan.

Gilly

Kyle Blackmore · #7 11-17-2002, 10:29 PM

Thanks Gilly,I'll check on those parts this week at the dealer.The adjusting rod seems fine and not stripped,unless it can snap off down below at the tensioner,but I don't think so.Thanks again for the help.