Tightening the drive belt

[Karen Lea Rainey]

Hi,

I tried for over 2 hours to move my alternator outwards to tighten the belt but i havent got long enough arms to reach and loosen the sliding bolt because the rear fixed steps are in the way.

The belt is very loose and it obviously isnt charging my batteries and its likely that it wont be driving the water pump very much either.

Its a magnetti marelli A127  55. On a bmc 1.5

There must be 2 inches of play in the belt, it goes round but  its probably not doing the job.

My question is,

If i remove the top 2 retaining bolts on the top of the alternator which i can get to will i be able to lever the alternator up the slide with a stick of wood or similar, will the alternator just roll over so that i can get to the bottom slide bolt.

 

Or do i call a mechanic, i know i can do it but am hoping for access to get easier, then how can i tighten it on the slider sufficiently to stay reasonably tight.

 

Edited July 29, 2017 by Karen Lea Rainey

[cuthound]

After loosening all the bolts, I use a long screwdriver or prise bar to lever and hold the alternator into the correct position with one hand, whilst tightening the  bolts withe the other. However this is on a Beta 43 battery charging alternator, so may not be directly applicable to a BMC 1.5.

[BEngo]

If you undo the top two bolts it is likely the altetnator will pivot about the adjuster bolt.  This is probably loose anyw as the amount of slack you describe is more than you would get from belt stretch or wear. 

If it has been slipping the belt is probably goosed anyway so I would also be prepared to change the belt now and get all the embuggerance over in one go.

N

[tree monkey]

I use a long bar and sorta push with my shoulder,  this leaving my hands free

[bizzard]

Slacken the top nuts and bolts, but you do need  somehow get to and slacken the adjusting bracket slot nut underneath to adjust it, and probably the adjusting bracket anchor bolt which is tucked further in underneath.

Edited July 29, 2017 by bizzard

[Karen Lea Rainey]

What about removing the top 2 bolts completely, then prise the alternator across, tightening the bottom bolt as much as possible, prise the alternator back in position and rebolt, alternatively i will need a very long 13mm ratchet and try to get on the nut, when i put my torch on the nut its very rusty indeed as if its not been moved in a very long time.

[bizzard]

8 minutes ago, Karen Lea Rainey said:

What about removing the top 2 bolts completely, then prise the alternator across, tightening the bottom bolt as much as possible, prise the alternator back in position and rebolt, alternatively i will need a very long 13mm ratchet and try to get on the nut, when i put my torch on the nut its very rusty indeed as if its not been moved in a very long time.

The top nuts and bolts on a BMC 1500 would normally be 1/2''AF spanner size and the main adjusting nut underneath on the adjusting bracket 9/16''AF spanner size. The adjusting bracket anchor bolt 1/2''AF spanner size.  Can you not lengthen your ratchet handle with a length of tube.

[Iain_S]

What tools do you have available? Socket set,  ring spanners, combination spanners, etc?

Some nuts and bolts can be a challenge to get at, but after the first time, it goes better next time because you have a method of doing it and know what works.

 

[Karen Lea Rainey]

Just went back to the boat, released both top nuts, slided the alternator across after undoing the sliding bolt,

The alternator was rusted well onto the brackets sliding arm, hit hit with a hammer to get it to slide, it wouldnt budge, undone the larger nut to get the whole alternator in a more favourable position to slide "AND DROPPED THE LARGER NUT HOLDING THE BRACKET IN THE OIL BILGE, god knows where it is its full of oil, 

Does anyone know what size nut it will be, was this nut the 9/16ths, it came off with a 15mm wratchet socket which didnt hold the nut and dropped out.

Oh where to buy AF size nuts now i wonder.

[bizzard]

10 minutes ago, Karen Lea Rainey said:

Just went back to the boat, released both top nuts, slided the alternator across after undoing the sliding bolt,

The alternator was rusted well onto the brackets sliding arm, hit hit with a hammer to get it to slide, it wouldnt budge, undone the larger nut to get the whole alternator in a more favourable position to slide "AND DROPPED THE LARGER NUT HOLDING THE BRACKET IN THE OIL BILGE, god knows where it is its full of oil, 

Does anyone know what size nut it will be, was this nut the 9/16ths, it came off with a 15mm wratchet socket which didnt hold the nut and dropped out.

Oh where to buy AF size nuts now i wonder.

Sounds like it.   9/16''AF spanner size is 3/8'' bolt or hole in nut size, but AF thread.  I'd dunk my hand into the oil and find it. It will be nicely lubricated. A single nut would be hard to buy, a boxful maybe, yes. The nut should be a self locking type of nut. There should be a big washer there too.

[Tony Brooks]

This is going to be an ongoing problem whenever the belt needs changing or tensioning.

I think the real answer is to deal with the rear fixed steps in some way. If wooden think about making them so you can lift the treads. Id steel  maybe you can cut a hole in the side plate above  a tread to give access and the screw a plate over the hole.

As Biz said you mat well have to loosed both the nut holding the slot and the slotted bracket's pivot bolt.

In some cases you might be able to reverse the bracket so the slotted section is at the other end if it makes access easier.