Thread: 300tdi Serpentine belt change

hi all,

I found this post really helpful, especially the diagram. I am changing my a/c belt and serpentine belt on my 98 300tdi and was wondering if there is a diagram/helpful info regarding a/c belt change.

regards to all Jim.

I don't have a diagram, but the A/C belt is a really simple one to change.
Assuming you've already removed the fan etc for access:

Loosen the 3 bolts on the idler pulley mounting flange and rotate it to release the tension on the belt.
Take the belt off, put the new one on, put a 1/2" square drive into the square in the idler and rotate it to put some tension on the belt.
Hold the tension on while you do up the 3 clamping bolts.

Make sure you get the correct length belts. There is a subtle length difference in early and late 300tdi belts (the main belt if I recall correctly). I think the later one is slightly shorter.

Steve

Originally Posted by steveG

I don't have a diagram, but the A/C belt is a really simple one to change.
Assuming you've already removed the fan etc for access:

Loosen the 3 bolts on the idler pulley mounting flange and rotate it to release the tension on the belt.
Take the belt off, put the new one on, put a 1/2" square drive into the square in the idler and rotate it to put some tension on the belt.
Hold the tension on while you do up the 3 clamping bolts.

Make sure you get the correct length belts. There is a subtle length difference in early and late 300tdi belts (the main belt if I recall correctly). I think the later one is slightly shorter.

Steve

I agree with all of this, but just want to add something about the belt length.

If the incorrect longer belt is fitted, it is not immediately obvious to a visual inspection. But the tensioner will not exert enough force and the belt can slip a little - enough to make the steering a little heavier.

Originally Posted by Bush65

I agree with all of this, but just want to add something about the belt length.

If the incorrect longer belt is fitted, it is not immediately obvious to a visual inspection. But the tensioner will not exert enough force and the belt can slip a little - enough to make the steering a little heavier.

The first time I changed the belt I got the wrong one. It was a tad too big.
I didn't notice anything different, the only problem was the belt only lasted about six months, probably due to unnoticeable slipping.

Dave.

hi all,

Thanks for the advice regarding a/c belt length, I made sure I had ordered the right one.

regards to all Jim

Originally Posted by Jim.

hi all,

Thanks for the advice regarding a/c belt length, I made sure I had ordered the right one.

regards to all Jim

I don't know of different lengths for the a/c belt. The discussion above on belt length difference applies to the other belt.