Thread: Alternator failure without warning - can it be anything else?

Originally Posted by sheerluck

If it was anything like my fan, Grant, you would have had great fun. I ended up cutting through the hub nut (where it attaches to the pulley) with a reciprocating saw

Hi Dave,
If the fan was fitted properly, it shouldn't be too tight, so a 10mm spanner on one of the nuts rested against the fan nut (to prevent it undoing the 10mm) is usually enough to crack it. I've had to do this a few times now and each time I mean to measure up to get a special tool made, would make life so much easier!
Cheers
Grant

Originally Posted by Presto

Hi Dave,
If the fan was fitted properly, it shouldn't be too tight, so a 10mm spanner on one of the nuts rested against the fan nut (to prevent it undoing the 10mm) is usually enough to crack it. I've had to do this a few times now and each time I mean to measure up to get a special tool made, would make life so much easier!
Cheers
Grant

I think mine was so awkward because the hub itself was slightly bent. I spent nearly a whole day trying to undo it. Even trying to shock it with a two pound hammer wouldn't do it, after heating with a torch.

It was only the heat and vibration from the saw that did it in the end. And then I found out how much a new one costs

Originally Posted by Presto

I found that the faulty alternator had a dead short

Did you investigate where the short was and if so, was it one of the main rectifier diodes?

Hi Graeme,

I haven't investigated that far yet, as I had to get the car running asap, so quickly checked across battery terminal before throwing it in a box and fitting the new one.

I'll take a look as soon as I get some spare time and report back.

Cheers
Grant

On D3 2.7 (trying to change alternator) Cannot find for certain whether the vicous coupling is a left or right hand thread. Hard enough to get undone without trying to make it tighter through going wrong way. Have seen various comments saying right and others left (may depend on LR models).
So can anybody tell me for certain which way I should be "persuading" it to get it off. Clockwise if LH thread?
Anybody know of any Australian suppliers for the tool to hold the pulley, while I encourage the coupling to detach?
OK, have found a definitie that says LEFT hand thread undo clockwise

Hey vbrab,
The link posted by Rich above suggested a left hand thread, and I used the procedure detailed there to remove mine. If you follow that procedure, it comes off easier than you would imagine.
Good luck!

Originally Posted by Graeme

Did you investigate where the short was and if so, was it one of the main rectifier diodes?

Hi Graeme,
Unfortunately, I caused a fair bit of damage trying to take it apart, and by the time I got into it, the short was gone
Without knowing what it should look like, there certainly seemed to be some melted connections which broke as I tried to dismantle it.
Now belongs in the bin!!

It seems that someone is now replacing the diodes in these alternators. Not sure I'd want a repaired one that had been potentially subjected to a short across it's windings though.

Landrover Discovery 3 Alternator | eBay

Regards,
Tote