M271 alternator freewheel

[tor_ake]

Getting squeeks from the belt on low rpm when e.g. turning to full lock, belt is new and tightener roll also.

Therefor suspecting the alternator freewheel. When i replaced the belt a while ago i spun the pulley by hand and couldn't feel a difference in spinning CW and CCW. In hindsight that probably means the freewheel has seized.

How do I go about replacing it? There are a few different tools on ebay, with concentric torx and xzn grips, is that all I need? Will there be any kind of violence involved in persuading it?

It's a C180 kompressor therefore the M271 engine, 120 Amp generator unsure wether it's valeo or bosch.

 

[grumpyoldgit]

Having never replaced, or worked on one of these I can't be much help to you I'm afraid. However, I did find a video on YouTube that may be helpful.......

Alternator Pulley Remover/Installer Kit ('Freewheel' Pulley) - AST4955A - YouTube


As an after thought....... If you only get a sqeak on full lock, isn't that more likely to be the power steering pump?

 

[duncanh]

As an after thought....... If you only get a sqeak on full lock, isn't that more likely to be the power steering pump?

It's more likely to be the alternator pulley.

 

[tor_ake]

I also had some trouble getting to grips with what was the likely fault. As I said, I have replaced the belt, and doing so, I examined all the wheels and pumps and whatnot, and they all move smoothly and without noise.

I am _guessing_ that since the tightener has no damper, the rotational vibrations from the crankshaft in combination with the alternator inertia causes the tightener to bounce, so the belt gets insufficient friction and starts slipping once you try to transfer any more than idle power.

There is also some short squeaks immediately on engine start (when rpm rises from cranking speed to idle)

 

[tor_ake]

Upon closer inspection, the inner socket is T50 and the outer probably the 33 XZN. I tried turning the alternator axle with a T50 socket and sure enough, the freewheel is totally seized.
Ordering new parts.

 

[tor_ake]

The T50 grip in the alternator stripped almost immediately, but 10-12 hits on the XZN spanner, emulating an impact wrench, loosened it.

Total operation time was about one hour.