300tdi serpentine belt

my serpentine belt snapped the other day,my mate gave me a belt, its spec is as follows 7pk1575, the correct spec should be 7pk1580. Anyway i fiitted the 7pk1575 and found that the tensioner could still move upwards by about 40mm. My question is this. Can i use the 1575 belt or do i have to fit the 1580 belt cheers.

you have to fit the correct belt - they're different lengths

thanks for the quick reply, but there is only a difference of 5mm in the two belt lengths and the tensioners still has plenty off free movement upwards. cheers

I'd agree with Trewy, but it's your call, your engine. Might be worth buying the correct belt and keeping the other for an emergency .. or to pass on to some other poor sod who's belt breaks at the side of the road!

Happened to me and a chap gave me a dodgy old belt he kept in his boot .. I now carry my old one when i replace them, hope to do someone else the same favour one day.

i suppose for the price of a couple of pints i may as well get the correct belt and keep this one as a spare cheers

Early 300tdi’s had a 61mm alt pulley which took the ERR3287 = 1595mm belt which can also be used on the later 49mm pulley (the tensioner will pull it to the same tension) although it uses the ERR5911 = 1580mm, using the 1575 will be fine, 5mm, the tensioner can take it, not like your are putting the 1575 onto the 61mm pulley.

Its also worth noting its the SAME tensioner that was used on both the 61mm and 49mm pulleys - although the belts was slightly longer the tensioner was still pushing further up. So buy putting a belt a mere 5mm shorter onto the smaller pulley version the tensioner is still well within limits.

thanks disco i thought it would be ok but its always best to check , cheers

Are we saying the alternators run at different speeds then with the different size pulleys or am I getting confused, I ask because I have a 200tdi alternator with the 61mm pulley running on a 300tdi engine 95, all seems to run ok, serpentine belt where the 200 was a single v pulley

Regards Pete

I believe the reason land rover fitted the smaller pulley to the alternator was to make sure the alternator still charged the battery even at tick over.

Interesting that there are two different belt sizes, I was doing some work on my 300 TDI Disco over the wekeend (timing belt change) and found that the new auxillary/alternator belt I had been given was too short for me to get the auto tensioner in place after re-fitting.

My car is a 1995 N registration, so I'm assuming it has the larger pulley and therefore belt. Suprised I was provided with the wrong one, bought from a reputable independent LR dealer and they entered my reg on their parts system.

Hi all, new here and I hope you don't mind me slightly hyjacking this but I keep getting home too late to ring a well known land Rover parts supplier to find out the serpentine and aircon belt correct belt part number for my lovely Disco called Pricilla.

She's a '97 on an 'R' reg 300 tdi ES auto with aircon.....am I Correct in thinking it would be ERR5911 = 1580mm for me too?

Many thanks

Kate