Alternator type

[Mingus1972]

Hello all.

Alternator pulley on my 09 D5 XC90 decided to seize and undo itself taking out the idler pulley. Looks like alternator FUBAR so ordered another second hand alternator from an 09 D5. Anyhow on checking the part numbers (i know i should have checked first but im used to old landrovers where if it looks like an alternator then it will probably fit) they are different. Old original broken alternator is 30667787, new one is 30667788. Will the new one work OK or should i get the original part number. Bear in mind im selling the volvo asap so lower cost is a plus and i kinda want to get it back up and running asap. Ta

[cheshired5]

Why not just change the pulley? They're replaceable and a lot cheaper.

[Mingus1972]

Originally Posted by cheshired5

Why not just change the pulley? They're replaceable and a lot cheaper.

Alternator looks pretty knackered after the bearing locked up.

[Tannaton]

On things like alternators and a/c compressors there are many different part numbers as manufacturers and specs changed over the years but they generally are interchangeable with maybe a few exceptions.

So as long as the electrical connections are the same and the replacement unit physically fits, I would expect it to be fine.

However I’m not clear on the problem - the alternator pulley is left hand threaded so can’t undo itself?

[Mingus1972]

Originally Posted by Tannaton

On things like alternators and a/c compressors there are many different part numbers as manufacturers and specs changed over the years but they generally are interchangeable with maybe a few exceptions.

So as long as the electrical connections are the same and the replacement unit physically fits, I would expect it to be fine.

However I’m not clear on the problem - the alternator pulley is left hand threaded so can’t undo itself?

Haven't checked yet but think the pully locked up and stripped all the threads from the shaft on the alternator. Pully had moved forward on the shaft about 2 cm and destroyed the drive belt.

[cheshired5]

Originally Posted by Tannaton

the alternator pulley is left hand threaded so can’t undo itself?

If the clutch seizes, the brief clockwise tugging on the pulley through normal operation is no longer absorbed leading to the pulley slowly but surely undoing itself.

Alternatively and more common is the alternator clutch seizing leads to the auxiliary tensioner working overtime to absorb increased vibration and wear out the tensioner pulley leading to derailment.

OP, any part should have cross reference numbers for compatibility and a decent parts supplier should be able to tell you that part x supercedes part y and is also compatible with part z etc.
Who have you bought from and why can't they answer what should be a straightforward question?

[SwissXC90]

Google shows

30667787 12V 140A (your original)
30667788 12V 160A (your replacement)

So the new one can do 20A more output.
Which won't be a problem.

You should be fine.