Hi,
One of the belts on my 1983 300D Mercedes is loose and wobbles wildly--
I am 99% sure its the belt that controls the A/C. It looks like the
parts are all solid, just needs adjusting. I felt the tension on the
other two belts and they are firm, but the belt in question has
quite a bit of give (about a 1/2 inch or so).
I couldn't find any previous postings on this....
Does anyone have experience tightening the A/C belt? Any help in how to
do this and also in how tight it should be? It looks difficult to get
to. Should it feel like the other two belts' tension?
Thanks,
Kate
T.G. Lambach - 27 Apr 2006 02:48 GMT
The A/C compressor's drive belt should be well tensioned - about like
the belt to the power steering pump.
One needs to loosen the bolts (probably three) that attach the
compressor to its bracket but NOT the bolt that secures the pipes to the
compressor.
My '80 has a tensioning screw with a small hex nut for a wrench, your
car may differ. Start turning it while watching the belt so it is
tensioned not made looser. I have to access the mounting bolts from
underneath but the tensioner from the top.
When you're satisfied with the belt's tension - and don't be shy about
tensioning it, the spec. is 1/4" deflection with a 13 lb push - tighten
the compressor's mounting bolts (to about 40 ft lbs.)
Done.
Be sure to note how many mounting bolts get loosened so the same number
are tightened.
kategrindlay@gmail.com - 22 May 2006 18:28 GMT
Turns out the problem was the screw that holds the AC unit down under
the hood had jostled out and the entire thing was rattling. This ended
up loosening the AC belt, but once I got it bolted down properly, the
belt tension restored on its own. I replaced the 2$ screw from the
hardware store (it was about 4" long), and the major rattle in my car
has gone away!