alternator

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kevin2

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Hi,
Have twin engine installation - Ford New Holland 160 hp each - I'm currently going through two alternators on each engine per year. Bearings keep collapsing probably due to pre tensioned belts being very tight and the alternator on the small side - currently AC127
What I need is replacement, heavy duty alternators possibly Bosch or similar, can anyone point me in the right direction - any suggestions?
Kevin.
 
If the New Holland Engines are fitted to agricultural machinery what do they use? I dont think Framer Giles would be too happy one two new ones a year.
A boat alternator does not have a lot to do as compared say to a lorry engine, so why use a pretensions belt. I would check the alignment of the pulleys.
 
There could be several issues here.

If the bearings are collapsing it is a sign of incorrect loading or a side loading caused by the pulleys being out of line, if the belt tension is too high it will accelerate wear, but not to the tune of two alternators per year.

Are you cleaning or spraying anything like degreaser into, or near the alternator? if so it could literally be cleaning out the grease from the bearings and leave them unlubricated, not an uncommon problem. Waterproofing compounds sprayed into alternators is often solvent based and can thin down the bearing lubrication and force a quantity of it out of the bearing.

Are the replacement units new or reconditioned units? many recon units have fallen foul of replacing the bearings with cheap copies of very poor quality from a number of third world countries. These are basically badged as a quality bearing, but are simply fakes, ask any Land Rover owner who services their own vehicles, fake parts have been a common problem for them.

If you have the old units you have two options, find the bearing size or part number, either will suffice, and go to your nearest bearing stockist, they will have heavier duty variants which you can replace yourself very easily. The heavier duty bearings should prevent this problem with the belt tensioned correctly.
Get a reconditioner to fit the bearings for you, you supply the heaviest duty bearing so you know they are the best bearing and it costs you only labour.
 
kevin2 said:
Hi,
Have twin engine installation - Ford New Holland 160 hp each - I'm currently going through two alternators on each engine per year. Bearings keep collapsing probably due to pre tensioned belts being very tight and the alternator on the small side - currently AC127
What I need is replacement, heavy duty alternators possibly Bosch or similar, can anyone point me in the right direction - any suggestions?
Kevin.
Click to expand...

Kevin,

Something real screwy here!

Let me make some assumptions...You have a pair of Ford NHD 675's OK. When the NH 6.75 was done front end was upgraded from earlier Ford motor with Polyvee belt and Dayco tensioner replacing nasty old twin V belt arrangement. This set up is maintenance free and should give alternator relief from being over tensioned, which is clearly not happening here.

I do not think Lucas AC AC127 was standard rotating electric dress on the the NH 6.75 so must have been fitted by the mariniser, Lancing, Mermaid? The Dayco self tensioning idler will have come set up for standard NH alternator dress. This is a case of learning basics of engine upfit, or more logically go back to Lancing/Mermaid and explain your problem, either way set up appears incorrect. May require Dayco idler with less tension, however experimenting different models can be expensive at £70/90 a pop.

Messing with different alternators is not the answer, root cause of problem needs to be addessed. No magic about Balmar alternators, all made by Leece Neville, same people who make Lucas design alternators these days.
 
kevin2 said:
Thanks guys that was most helpfull, could well be the re-conditioned alternators.
Click to expand...

Sorry Kevin, but you do not seem to have digested a darn bit of what I am saying..........

New pair of re-conditioned alternators may well leave you in exactly the same hole! Different flavour of the same ****.

I give up! Sorry to be rude but talk about trying to educate pork!
 
Could be the pulley too small.

So alternator spinning too fast and running the bearings too fast.

My kad42 replacement alternator came with a smaller pulley, so we changed it for the original one before fitting.
 
Who said:
Could be the pulley too small.

So alternator spinning too fast and running the bearings too fast.

My kad42 replacement alternator came with a smaller pulley, so we changed it for the original one before fitting.
Click to expand...

It could be a number of issues, but absolutely no point in stabbing in the dark.

I went to the trouble to drag out my Ford 'Genisis' CNH engineering notes in order to try and assist this guy, it is pretty clear this is all about understanding the belt set up and working the numbers, not just playing musical chairs with different alternators pully sizes or idler tensions, or perhaps alternative belt lengths. Just a simple matter of back to basics, understanding the issues and coming up with a solution........it is called engineering.
 
The root cause does need identification, and ihave assumed the original pulleys were the correct size for the alternator, and fitted to the new units, however this may not be the case.
 
Do the alternators run hot on the casing, are they rotating clockwise as viewed from the front? are they getting enough air over the fans to cool the casing, all will contribute to premature bearing failure.
 
Latestarter1 said:
Sorry Kevin, but you do not seem to have digested a darn bit of what I am saying..........

New pair of re-conditioned alternators may well leave you in exactly the same hole! Different flavour of the same ****.

I give up! Sorry to be rude but talk about trying to educate pork!
Click to expand...

yes i did get that, will try speaking to lanceing who did the engine
 
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