Is my alternator stuffed?

[Whitey1 Advanced Member Find all posts View Profile Close Whitey1]

I've had one of those voltage boosting diodes in mine for years, replaced it last year because it blew, but my alternator has never given me trouble, 220000 km and still going strong.

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

Alternators will in theory last forever, but in a 4wd which gets mud and dirt baths that lifespan is reduced and reduced.

[Corigator Avid PP Poster! Find all posts View Profile Close Corigator]

Alternators will in theory last forever, but in a 4wd which gets mud and dirt baths that lifespan is reduced and reduced.

Not so sure about that, Jimmy. The bearings will eventually die, unless you have the frictionless variety. If so, please let me know where you get some. - Cheers

[GEEEXL Member Find all posts View Profile Close GEEEXL]

Don't really know. I wouldn't think it was likely to result in excessive duty for the alternator. A 0.8V step increase over say 13.6V is 6% increase, but max power output is only required from the alternator for a short period of time so it seems unlikely, but I don't really know. It's a bit disappointing to have an alternator fail after only 140,000 km but I'm happy to believe its just a random early life failure.

I wasn't having a go at the diode as such, just the manufacturers that are constantly trying to make things cheaper and JJJUUUUUST strong enough to outlast a warranty etc?

G

[andoland Senior Member Find all posts View Profile Close andoland]

JimmyC or anyone else who has done this, I've loosened the bolt on the tensioner pulley, but the belt tension has not released. Is there some trick to it?

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

You need to put a spanner on the bolt, do not undo it! Push the spanner clockwise towards the left fender. This will cause the pulley to move inwards and thus relieve the tension. I use a long spanner with a piece of square tube steel over it to make it nice and long. Some people use a bungy strap to keep the tension on the bolt so the pulley stays across whilst you fit the belt.

[andoland Senior Member Find all posts View Profile Close andoland]

Awesome, thank you bushbasher. I was following JimmyC's instructions and didn't realise he was describing the direction from underneath the vehicle.

[andoland Senior Member Find all posts View Profile Close andoland]

Ok, job done. Only took me about 4 hours lol. Main issues were that I misunderstood which way to turn the belt tensioner pulley (thanks Bushbasher for clarifying, otherwise I would still be there swearing at it ) but then I couldn't get the front bashplate off because a) one of the bolts had a rounded head and b) because of the stupid design of the TJM bullbar the bottom edge of the bullbar lower guard was preventing the bashplate from lifting up enough to get the little retaining lugs out of the holes. I seriously think I spent more time getting that @$%ing thing off than any other part of the job. I had to go to Bunnings to pick up one of these http://www.irwin.com.au/tools/extraction/bolt-grips - man how good are they for pulling out bolts with rounded heads!

Once the old alternator was out it took literally 5 minutes to get the new one in, bolted up and the belt back on. The car is now running fine with the alternator putting out ~14V.

[Razorback81 Advanced Member Find all posts View Profile Close Razorback81]

good work mate !

we had to sort out a 79 series wagon on our last trip
did the big mud splash and drove through 40ft of muddy water
next day we heard "Gee's now my alternator light has come on"
we poured water over it an it went out then 1/2hr later back on
so we ended up pulling it off to clean the brushes out
( for those interested there is 5 bolts holding a V8 alternator on)
( 1 is hard to find !! because you can only feel for them, 2 of the studs need to come out of the block to let the unit come out !! )

2 x little screw on the back and the brush holder comes off, we sprayed CRC and air in to them and they freed up,
then you need a thin wire to hold them (through a little access hole) while you fit them back on

does the unit still spin freely ?

now you need to undo the the rear brushes and see if they are stuck

or

check the front pulley has let go

[andoland Senior Member Find all posts View Profile Close andoland]

Yeah it still spins freely. CBF doing anything with it, the new one is in and working so that's all I need.