Alternator trouble

[bleh]

Hey there been having issues with charging the starter battery, I'm going to replace the alternator belt as the alternator was as far as it could be on the tensioner bolt. When checking the tension I noticed the mount the alternator sits on has some movement.

What would people suggest to stop this from happening? I've been told try squeeze in some copper washers but wondering if anyone has any better ideas! Thank you 

[Tony Brooks]

What engine is that, and I can't see the alternator in that photo so not sure what has the movement. It looks to me as if the bolt is undersized or worn, or the hole on the end of whatever it is, is worn. The "bolt" might be a hexagon set screw where its threads have been squashed by constant movement. If it is a set screw try using a proper bolt with a length of plain shank.

 

I don't think it would be sensible to try to squash the two mounting lugs on the engine together to try to grip the "thing", I fear one may split or break at the weld.

[bleh]

I think it's the Volvo penta MD21? I know it's an indenor xdp 4.90 engine base I think then marinised by Volvo. What I'm holding in the video is the alternator and the movement is from where the alternator mounts (that attach alternator to the engine) attach to the engine. 

 

Yep good point about it potentially being a threaded bolt, I've just been avoiding taking it off in the hopes I was missing something obvious. I'll remove and have a look at the bolt holding it! 

 

The last thing I need would be broken mounting lugs so won't be trying to squish in a washer!! 

[Tony Brooks]

21 minutes ago, bleh said:

I think it's the Volvo penta MD21? I know it's an indenor xdp 4.90 engine base I think then marinised by Volvo. What I'm holding in the video is the alternator and the movement is from where the alternator mounts (that attach alternator to the engine) attach to the engine. 

 

Yep good point about it potentially being a threaded bolt, I've just been avoiding taking it off in the hopes I was missing something obvious. I'll remove and have a look at the bolt holding it! 

 

The last thing I need would be broken mounting lugs so won't be trying to squish in a washer!! 

 

Unless it is a very odd alternator the part you are waggling is not part of any alternator I know. 

 

Alternators typically have three or two mounting points. A long single one or a pair (front and back) that are bolted to a bracket rigidly fixed to the engine in the same plane as the alternator end plate mounting points. The alternator swivels on these for belt adjustment. The other fixing is the adjusting arm that the remaining alternator end bracket can move along and be clamped to.

 

The arm you can waggle has its web at 90 degrees to the alternator bracket and is a totally separate part. It can't be an adjusting arm because as far as I can see there is no means of moving the alternator to different positions along it. 

 

If it is supposed to be a fixed rear alternator mount then what stops it simply swivel and dropping down, so the alternator goes out of line with the belt.

 

At best, on the present information it seems like a bodge to me and I can't see PSA doing it, so presumably a Penta part.

 

I would like to see some more photos showing the way the alternator is mounted on the engine and adjusted, both from the front and back.  I don't know if anyone else thinks it all looks odd.

 

 

[Peugeot 106]

Should it have a sleeve in it? 

[bleh]

19 hours ago, Tony Brooks said:

 

Unless it is a very odd alternator the part you are waggling is not part of any alternator I know. 

 

Alternators typically have three or two mounting points. A long single one or a pair (front and back) that are bolted to a bracket rigidly fixed to the engine in the same plane as the alternator end plate mounting points. The alternator swivels on these for belt adjustment. The other fixing is the adjusting arm that the remaining alternator end bracket can move along and be clamped to.

 

The arm you can waggle has its web at 90 degrees to the alternator bracket and is a totally separate part. It can't be an adjusting arm because as far as I can see there is no means of moving the alternator to different positions along it. 

 

If it is supposed to be a fixed rear alternator mount then what stops it simply swivel and dropping down, so the alternator goes out of line with the belt.

 

At best, on the present information it seems like a bodge to me and I can't see PSA doing it, so presumably a Penta part.

 

I would like to see some more photos showing the way the alternator is mounted on the engine and adjusted, both from the front and back.  I don't know if anyone else thinks it all looks odd.

 

 

Yep it's definitely a bodge, whoever was putting this engine together wanted to do it quickly! What I'm holding onto in the photo is this homemade lump that the alternator then attaches to 

 

18 hours ago, Peugeot 106 said:

Should it have a sleeve in it? 

Do you know anywhere I could find sleeves? It's a M10 bolt. The only problem I'm thinking is that it's a homemade part and the holes are a little irregular 

Just if anyone has any ideas how I could make this work I would really appreciate it! 

[Tony Brooks]

Thanks for that. It is what I suspected it was.

 

I expect the holes are worn by constant vibration as is the thread by the look of it, and regrettably I can't think of a simple/easy way of solving it. I think even if you fund a dowel bolt that has a slightly oversized shank to take the play out there would still be problems because there is nothing to clamp that arm it the correct angular position.

 

I don't know how PSA fitted the alternators in vehicles, but am all but sure it was not using that. 

 

Looking at the double lug where the bolt with the play runs through. It looks as if those lugs have been welded to the engine block that seems an odd think to do.  Can you find three screws/bolts, or two at a pinch, that you could use to fix a rigid bracket to the engine with it outer hole in the same position as where the movable arm's one is. It would have to be made from say 6mm plate and bent at a right angle so one side fits tight against the block and the other is in the correct position for the alternator mount. 

 

I think that I can see the top of an engien mount stud in your video. Another way could be to make up a long and strong strap, bent up and twisted to fit, that runs between the mount stud (nutted down tight onto the mount nut) and the back alternator bolt, so that arm is held in the correct position.

 

I wonder if this is the result of fitting a non-standard, larger, alternator or fitting twin alternators. If you look carefully you might find the now redundant original back mounting point.

 

[ditchcrawler]

3 minutes ago, Tony Brooks said:

Thanks for that. It is what I suspected it was.

 

I expect the holes are worn by constant vibration as is the thread by the look of it, and regrettably I can't think of a simple/easy way of solving it. I think even if you fund a dowel bolt that has a slightly oversized shank to take the play out there would still be problems because there is nothing to clamp that arm it the correct angular position.

 

I don't know how PSA fitted the alternators in vehicles, but am all but sure it was not using that. 

 

Looking at the double lug where the bolt with the play runs through. It looks as if those lugs have been welded to the engine block that seems an odd think to do.  Can you find three screws/bolts, or two at a pinch, that you could use to fix a rigid bracket to the engine with it outer hole in the same position as where the movable arm's one is. It would have to be made from say 6mm plate and bent at a right angle so one side fits tight against the block and the other is in the correct position for the alternator mount. 

 

I think that I can see the top of an engien mount stud in your video. Another way could be to make up a long and strong strap, bent up and twisted to fit, that runs between the mount stud (nutted down tight onto the mount nut) and the back alternator bolt, so that arm is held in the correct position.

 

I wonder if this is the result of fitting a non-standard, larger, alternator or fitting twin alternators. If you look carefully you might find the now redundant original back mounting point.

 

Could the engine end be welded once iys it the correct plane 

[Tony Brooks]

1 minute ago, ditchcrawler said:

Could the engine end be welded once iys it the correct plane 

 

Yes, but I would not like to try it with either a cast iron or aluminium block. Too close for my liking.

Edited April 7 by Tony Brooks

[ditchcrawler]

4 minutes ago, Tony Brooks said:

 

Yes, but I would not like to try it with either a cast iron or aluminium block. Too close for my liking.

The present end looks welded to the block and with the bolt through you would only need to part way round the pipe bit and the lugs.

Another option to get a bolt made and ream the pipe to an exact or interference fit 

Edited April 7 by ditchcrawler

[Tony Brooks]

Just now, ditchcrawler said:

The present end looks welded to the block and with the bolt through you would only need to part way round the pipe bit and the lugs

 

I agree, but can the OP weld, or is whoever he employs used to doing that kind of welding. I suspect it would have to be stick welded because of the thickness of metal involved.

[Eeyore]

Well thats a fun thing!

Of more concern to me would be that the bores at each end of that link are not even close to parallel.

This suggests that the welded lugs on the engine are not holding the bolt parallel to the crankshaft.

A photo looking forward towards the back of the alternator might be useful.

[ditchcrawler]

14 minutes ago, Eeyore said:

Well thats a fun thing!

Of more concern to me would be that the bores at each end of that link are not even close to parallel.

This suggests that the welded lugs on the engine are not holding the bolt parallel to the crankshaft.

A photo looking forward towards the back of the alternator might be useful.

Maybe that bit of the engine block is not parallel to the crank 

[Peugeot 106]

3 hours ago, bleh said:

you know anywhere I could find sleeves? It's a M10 bolt. The only problem I'm thinking is

It might be easiest to

 

1) measure the distance between the lugs accurately. You could sand away at a piece of wood, plastic pipe or whatever to find a snug fit and the best length

(this is so that there is no risk of breaking the lugs when you tighten up)

2) take your bracket and bolt to a fabrication shop

3) cut off the wrong size pipe and weld a new correct sized one on. Inside dia to fit bolt correctly and length the same as your template. The correct sized pipe could actually be a slightly larger diameter bar drilled to suit the bolt than the present one 

 

you are best in this scenario keeping to a fully threaded bolt so it is the same diameter for all its length

 

Make sure you position the new pipe axially the same as the old on so that the pulleys are lined up

[Eeyore]

3 hours ago, ditchcrawler said:

Maybe that bit of the engine block is not parallel to the crank 

Yes, they must of had some fun tacking it all together whilst holding the alternator in the correct position to maintain the belt alignment. 

[Tony Brooks]

14 hours ago, Peugeot 106 said:

It might be easiest to

 

1) measure the distance between the lugs accurately. You could sand away at a piece of wood, plastic pipe or whatever to find a snug fit and the best length

(this is so that there is no risk of breaking the lugs when you tighten up)

2) take your bracket and bolt to a fabrication shop

3) cut off the wrong size pipe and weld a new correct sized one on. Inside dia to fit bolt correctly and length the same as your template. The correct sized pipe could actually be a slightly larger diameter bar drilled to suit the bolt than the present one 

 

you are best in this scenario keeping to a fully threaded bolt so it is the same diameter for all its length

 

Make sure you position the new pipe axially the same as the old on so that the pulleys are lined up

 

However, the two fixing eyes on alternators, not the adjusting eye, need to be in line with each other and permanently kept in line. I can't see how that strap that is fixed to the engine at one end can ever be relied on to keep the back mounting point in the correct position unless it is braced or fixed to prevent rotation on the engine end bolt in same way. Just getting rid of the play can't be a long term answer, simply relying on friction between the two engine lugs and the boss on the strap can never be reliable, especially in view of the thickness of those lugs.

[Tony Brooks]

Added for clarity:

 

If that arm drops on the pivot at the engine end while in use it is likely to snap one of the alternator end brackets, I suspect the front would be the most likely, and the pulley would run out of alignment, causing rapid belt wear.