Alternator pulley and belt

Mr Angry

Mr Angry

A2OC Donor
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Hi Guys,

I'm in the process of checking some threads regarding my current problem.

Yesterday the drive belt snapped while my wife was driving the car and upon inspection everything else seemed ok so i replaced the broken belt today. My wife had only driven about 1 mile before power steering light came on along with a burning smell and a weird clattering noise from engine bay :/ When she got home i checked where i had replaced the belt only to notice that the alternator pulley had sheered off with new belt resting on the metal bar/pole/rod from alternator. That would be the burning smell that she experienced with it rubbing lol

So....my question is what is the best option to take here... buy a complete alternator or get a new pulley with whatever attachments/tools i need for the job?

Will i need to get another new belt because of what happened with the pulley?

A special thanks to Devans for providing help with belt change :) I would've posted on forum but checked a thread of his and managed to change successfully :)

Have a good xmas and new year everyone :D

TIA

Cammy
 
Assuming the alternator is OK A new override pulley will fix the problem. You will need a special tool to do the changeover.
 
i've seen a photo in another thread showing the rod has tapered inwards to a point, mine is still intact and looks ok but i will take a photo and upload. Is there anything else suspicious to check on the alternator?
 
If the bearings are ok which you can hear/feel as you rotate the shaft. Electrically checking is a bit more problematic. If the diodes are breaking down then a slow current drain can occur. The output voltage can also reduce which gives charging problems. Generally alternators are robust and reliable, until they go wrong!
 
Generally alternators don't go wrong, unless the bearings are worn out, people are tricked into spending a vast amount on a new one when all they need is the regulator module which is in the region of £20-30. The pulley is cheap too, changing it can be tricky though even if you have the correct tool, an air impact driver is often also needed. I had to admit defeat with mine and take the alternator to a local workshop to get the remains of the old pulley off and they installed the new one at the same time.
 
With the belt off, if the alternator spins smoothly and quietly then you should be fine with just the pulley. Also, it doesn't look like the belt is damaged but it would be worth checking the inside face to make sure.
 
Tip for the tensioner. Use a spanner to rotate the tensioner until the two holes meet, insert a THREADED bolt through the movable portion into the fixed part. Replace the pulley and belt, get it all lined up and gently unscrew the previously inserted bolt. It will suddenly go ping and the belt is tensioned again.,
The tool you need to replace the pulley drive is this one
 

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It is anti clockwise to undo, just fitted a new pulley to the tdi i am doing up. i had to cut the old one off.
 
I had the same problem where my alternator pulley actually flew off, luckily I was in a garage with the bonnet removed inspecting it at the time and it went rolling on its merry way along the garage floor, fortunately without causing any damage to me or the car.

I personally decided to go the route of having a new original equipment INA pulley fitted to my original Bosch 140 amp alternator (2003 tdi 75) which I removed and also had reconditioned at the same time just for peace of mind (although there was nothing wrong with it other than being 17 years old at the time). The original pulley from memory was around the £30 mark but I didn't have the correct tool to replace it so took it to a company called Rotating Electrics in Birmingham and tbh I'm glad I did as the chap told me he broke two spline bits removing the remnants of the old one before fitting the new one, reconditioning and repainting the alternator whilst I waited, all in about an hour and for around £70 all in (again from memory). I did post it in a thread on here at the time but not sure where.

I decided whilst refitting the alternator to also replace the auxiliary belt and the belt tensioner whilst in the area and for a complete job, which was again replaced with the same original part made by INA/Schauffler which was around £35 off ebay (£70 from Euro Car Parts) just so i knew it was something that shouldn't then need any attention again for the next 15 years or so.

I would definitely recommend them if you decided to go a similar route 👍
 
I had a new INA bearing put on mine under a month ago, because it was the OEM fitment. The garage had fun getting the seized old one off. However the replacement has already started making a noise like a loose belt under electrical load from a cold start, except it's metal on metal not rubber on metal. I think it's actually slipping internally - if it was slipping on the shaft it would have come off by now! Hopefully it makes it through to get further attention early in the new year.
 
simufly said:
Tip for the tensioner. Use a spanner to rotate the tensioner until the two holes meet, insert a THREADED bolt through the movable portion into the fixed part. Replace the pulley and belt, get it all lined up and gently unscrew the previously inserted bolt. It will suddenly go ping and the belt is tensioned again.,
The tool you need to replace the pulley drive is this one
Click to expand...
Hi is this the tool for the alternator belt pulley. I had to replace my drive belt and think I may need a new pulley as well . I did replace the tensioner but not the pulley

Sent from my Nokia C01 Plus using Tapatalk
 
Simon, i've seen a few similar tools like yours but some people have complained about the flange at the end of the torx shaft, as the only way to use a ring spanner rather than an opened end, is to grind the flange off. Did you have any issues with ring spanners when using your own? The only reason why i'm looking at other options rather than the options above is Amazon can deliver the tool for Thursday, which is useful as i'm only off this weekend.

here is the amazon one....

https://www.amazon.co.uk/BGS-Intern...32?keywords=m10+spline&qid=1672177128&sr=8-32

Just trying to source the pulley so i can get it for Friday latest

Thanks for your help on this guys :)
 
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I managed to get the belt back off and rotate the shaft as you guys have mentioned, belt looks ok and intact with no tears, rips etc... There is a slight noise when turning. I would say you need to be very close to hear it though but it does move freely. Does the shaft look ok in these images? I ordered a 16mm angled tool from Amazon for better use when moving the tensioner however, Amazon have sent a 19mm instead of a 16mm...idiots!


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I doubt there is anything wrong with the shaft, that is the remains of the pulley that you have to remove. You'll need the alternator out to do it.

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That spline you can see is the inner core of the pulley.
 
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Mr Angry said:
Simon, i've seen a few similar tools like yours but some people have complained about the flange at the end of the torx shaft, as the only way to use a ring spanner rather than an opened end, is to grind the flange off. Did you have any issues with ring spanners when using your own? The only reason why i'm looking at other options rather than the options above is Amazon can deliver the tool for Thursday, which is useful as i'm only off this weekend.

here is the amazon one....

https://www.amazon.co.uk/BGS-Intern...32?keywords=m10+spline&qid=1672177128&sr=8-32

Just trying to source the pulley so i can get it for Friday latest

Thanks for your help on this guys :)
Click to expand...
I did not have a problem removing the old pulley. An open ended 17mm was fine.
From memory I did use an impact driver. It is much easier to replace the pulley with the alternator out of the car. It probably can be done in situ but torquing it up would be a nightmare.
Looks like the inner pulley on your alternator is still on the shaft. This will need to come off first.
You are more than welcome to borrow the tool if you want.
 
AndyP said:
I doubt there is anything wrong with the shaft, that is the remains of the pulley that you have to remove. You'll need the alternator out to do it.

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That spline you can see is the inner core of the pulley.
Click to expand...
The spline part that is on the shaft, should that just slide off or will this be stuck? should i use a pair of grips back and forth to remove it? Is it much harder to install the pulley with alternator in position? I might just buy a 2nd hand alternator with everything in situ avoiding this procedure...

I will see if anyone has a spare working 2nd hand alternator on the forum.

I will keep you posted.
 
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