What's the deal with 45A/90A alternator brackets?

[Rusty84]

Hello, 

is it possible to use the alternator bracket for the 90A, the one with the the tensioner bolt, on a 45A alternator?

I'm asking as the belt keeps loosening off on mine and doing my head in. 

The water pump spins freely, so does the alternator, it has the 10 x 1075 belt (i've tried various brands), I've used belt dressing spray, all the pulleys are perfectly in line. But i have to readjust the damn thing every other journey. 

And so the 90A bracket looks appealing, but will it fit?

Searched the forum but couldn't find anything.

Thanks.

[silverbullet]

Should fit ok, you need the special pinion bolt that goes with it obvs.
Its important to loosen the alternator pivot bolt before tensioning and then retighten afterwards.
Also check that the alternator bracket itself is secure on the engine case.

[lefty67]

Should it have a biggish spring under the alternator to act as a tensioner? Mine has but this was missing when I first got the van and was having to do the same thing as you.

[ExploreElysium]

From what I've seen, the 90A bracket with the tensioner bolt should work with a 45A alternator, as long as the mounting points line up. It's definitely worth trying since it might help with the belt tension issues you're having. Just double-check the fitment before committing.

[Aidan]

have you had your pivot bolt out to take a good look at the threads on that and the nut, they may well be poor (ie worn out threads at the point the nut is doing the clamping work), and there should be a spring washer under the nut, unless you have the Syncro stone deflector version of the bracket with the square rear hole at the back and which uses a coach bolt instead of the plain bolt fitted to most. I'd modify the bracket to take a coach bolt anyway as it saves having to get a spanner in on the back of the bolt whilst nipping the nut up, if you have power steering the access is pants so you need a socket and extension to get on the back of the bolt anyway - frankly I don't know why the coach bolt set up wasn't universal, maybe they felt that 2 opposing spanners meant that peeps wouldn't overtighten the nut and damage the threads, but since it is easy to lean on the tightening tool it is actually counter productive I feel

Also check to see if the bracket is fractured, it is quite common for them to crack, and then it is the pivot bolt holding it all together

And you may need to replace the locking bolt with a fresh one and check threads in alternator aren't also worn, if in doubt use a longer bolt and put an extra flange nut on the exposed thread

there shouldn't be a spring or anything under the alternator taking up slack that's just a bodge imho