Disco 2 TD5 10p engine......are the belt tensioners self tensioning?

Hi All,

I know this question has probably been asked before, but the search function isn't working and I don't have time to scroll through the threads to find the answer (at work you see ), but, as per the title, I'm looking to find out if the belt tensioner on the 10p engine are self tensioning or not?

I'm needing to replace the alternator and need to loosen and slacken off the belt tensioner. Its my first time tackling this (abs pump next), and getting to the bolt on the tensioner is a real bitch when you don't have the right spanner to get to it.

Cheers

The bolt in the middle of the tensioner pulley needs a 15mm ring spanner or socket. This bolt is a left hand thread so to take the tension off you need to turn it in the clockwise direction (RHT tighten).

To remove the tensioner unit from the front of the block you will need a 14mm multipoint thin walled socket to fit on the head of the bolt which is sunk in the unit. RAVE points to this bolt and has it marked as left hand thread, but it's an error. The bolt holding the unit to the engine block is right hand thread. The bolt in the centre of the tensioner wheel is left hand fred.

With the viscous fan removed it's a pretty straightforward job.

And yes, the belt is automatically tensioned. A new tensioner is about 22 quid.

Many thanks Brian, well written and informative post. I'm guessing it's always better to replace the tensioner rather than just sticking with the original?
I didn't think it looked a difficult job, just more awkward if I didn't remove the fan.
Funnily, I'm finding this more daunting than changing the abs unit over.

Yes, it is a lot more awkward if you don't remove the fan, I'd go so far as to say it's almost impossible without taking the fan off. It's a reasonable idea to replace the tensioner while you've got access to the front end of the lump.

That job itself really needs the proper set of spanners but once you have them it's just a bit of a fiddle to hold the spanners and get the removal of the fan started. Such a pair of spanners will cost about 20 quid upwards, depending on where you get them. But once you've got them the won't eat nor drink until the next time you need them.

Just out of interest, why are you considering changing the ABS unit?

Grim said:

Many thanks Brian, well written and informative post. I'm guessing it's always better to replace the tensioner rather than just sticking with the original?
I didn't think it looked a difficult job, just more awkward if I didn't remove the fan.
Funnily, I'm finding this more daunting than changing the abs unit over.

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abs is quite straight forward all easy to see and get to alt is a lot trickier, youll find it better to remove the egr unit,and when refitting lower alt securing bolt get someone to hold the nut in the rear of bracket as its not secure and can drop out or go cross threaded

brian47 said:

Yes, it is a lot more awkward if you don't remove the fan, I'd go so far as to say it's almost impossible without taking the fan off. It's a reasonable idea to replace the tensioner while you've got access to the front end of the lump.

That job itself really needs the proper set of spanners but once you have them it's just a bit of a fiddle to hold the spanners and get the removal of the fan started. Such a pair of spanners will cost about 20 quid upwards, depending on where you get them. But once you've got them the won't eat nor drink until the next time you need them.

Just out of interest, why are you considering changing the ABS unit?

Click to expand...

I did used to have a decent set of tools, but the ex-wife had most of them when we split (she’s better under the bonnet than me!!). I’ll have to invest in a new set of spanner’s ‍.

Needing to change the abs pump due to the three amigos. Had a fault on pump 2 (actuator not working properly), so needs a new unit. Once that’s on, it’ll need plugging into a nanocom again (power bleed etc).