how to release tension to remove/install serpentine belt

[wslthompson]

I have a 1990 300E and need to replace the belt. Any information would be greatly apreciated.

ie.
Manuals pdf format
website links,etc


Thanks

wslthompson@comcast.net

 

[television]

Have a look at your car here.

http://www.detali.ru/cat/oem_mb0.asp?TP=1

Go to engine cooling, then belt tensioner, I believe that I am right in saying that you un hook the spring, if I am wrong here, someone will soon tell you.

Malcolm

 

[Bolide]

Tensioner

On my 250TD there's a black plastic block at the front of the cylinder head that's attached to the spring. If you remove the bolt that holds the top of the block in place you can release & retension the belt using a 10 mm rod in the hole in the top of the block. The block pivots on the bottom mount. Just use the rod as a lever to retension it

Bear in mind that high-mileage cars may well have noisy and/or worn idler bearings and now is the time to change them. Ditto water pump, tensioner and tensioner damper

Though if it's anything like my 250TD was the original water pump will be perfect at 230k miles...

Nick Froome
www.w124.co.uk

 

[mike65]

I imagine its very simliar to the 190e which is to loosen a 17mm bolt head just by the rad fan and then to turn the tensioner arm sticking up out of the tensioner body.

ah here it is - http://www.detali.ru/cat/oem_mb2.as...GM=717.433&CT=M&cat=14K&SID=20&SGR=045&SGN=03

Mike.

 

[tom7035]

Here's the routeing if it helps;

 

[Stevie A]

The big bolt / nut holds the tension. The smaller nut is used to adjust the belt tension before tightening the larger bolt. Slacken off the small adjuster nut first then the big one to completely release tension.

On replacement add tension by turning the small adjuster, then once the belt feels tight enough (there is a small plastic tension gauge) tighten the large nut. There is a good description in the Haynes manual how to do this correctly.

Check for tension before you replace old belt to see correct play in belt.

I am presuming the adjuster set up is the same as a 190E.