Setting belt tension ... special tool or feel?
 

... going to do the accessory belts on my 240D in the next few days and was wondering about setting the tension ... is it OK to do it by feel, or is there any advantage to using a tool? If you do it by feel, is it pretty much common sense as to what the appropriate tightness is?
Right now it has the wrong belt on the A/C compressor and its squealing. Other two belts look OK but I'm replacing them anyway due to unknown vintage.

I've never used any special tool. Feel works for me. Tight.

I like to have mine set a little bit tighter than the point where they squeal under acceleration. Tight enough to not squeal, loose enough to keep the bearings happy :).

NAPA sells a tension gauge called a Kriket for a reasonaable price. Once I started using a gauge, I was shocked at how inaccurate the various "rule of thumb" methods are.

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=NBH&PartNumber=KR1&Description=Belt+Tension+Gauge

It can be done without the gauge.

The V-belt system provides a good bit of latitude with regard to tension. Over the years, I've come to realize that the tension set by most folks is way too tight. The belts can transmit much more torque with lowered tension settings than one would initially believe.

After installing a new set of belts, they'll typically stretch a bit, sometimes to the point of being visibly loose. No hint of slippage on the component.

I set them to that there is a good 1/2" of movement when the PS and ALT belts are pressed in the middle. The a/c belt will be less, possibly 1/4", due to the short distance between the two pulleys.

Just remember............tighter is NOT better.

Which is precisely why using a gauge is such a fantastic idea!!!

Think of all the crank pulley bolts that could be saved.

I should pick one of them up......what's the cost?

NAPA webside lists $13.99. Click the link in post #4.

Thanks......that's cheap enough to make it worthwhile to have.

I bought one of the gauges at Napa and a set of belts but I still haven't had a chance to put the belts on. At work I do a lot of belt changes and I have done it with and without a gauge and for consistency it's best with a gauge.

Thanks for the advice, all. Looks like the tool is a cheap way to get extra assurance I've done it right, and I like my local NAPA guys, so I'll pick one up.

I got all the belts yesterday from the dealer, so hopefully I can actually get to this job soon. I don't know how you guys with like 10 cars can do it all. I have a growing list for just three. I like doing it all but it's hard to find the time with my funky work schedule. 4 a.m. isn't really a good time to change belts, is it?:eek:

Why not?

Dark, damp, rabid raccoons.:cool:

Actually I've done quite a few things at that hour, but usually things I'm more familiar with (e.g. oil change) or things that can be done inside (repairing door lock tumbler for example). Now that I'm living at my parents house I kind of have to be considerate about waking them and the neighborhood too.:eek:

time to get a garage...

It's high on my checklist whenever I decide to buy a house. Big garage, big driveway ... if there's a house attached to it, bonus.;)