Replace that alternator ducting!
06-18-2004, 09:33 AM
#1
Three Wheelin'
Thread Starter
Replace that alternator ducting!
I'm in the process of "restoring" an '86 951, and as a result I have pretty much disaddembled the engine bay.
One item that really suprised me was the alternator. The case was looking pretty nasty, so i decided to remove the alternator and take it apart for a good cleaning an electrical inspection.
When I pulled the voltage regulator discovered the brushes were worn completely down, and the slip rings had deep grooves.
Further inspection revealed that the rotor and stator windings were covered in a layer of dirt and oil.
Looking at the situation I realized that because the flex pipe was missing, oil mist and dirt were being sucked up into the alternator. Once inside, the oil and dirt became a sort of lapping coupound which caused the slip ring grooving and excessive brush wear.
Luckily I have a spare voltage regulator, but I am having some difficulty finding a shop that can repair the slip rings, which may force me to replace an other wise "good" alternator.
So, a word to the wise: Make sure that flex pipe is in place!
One item that really suprised me was the alternator. The case was looking pretty nasty, so i decided to remove the alternator and take it apart for a good cleaning an electrical inspection.
When I pulled the voltage regulator discovered the brushes were worn completely down, and the slip rings had deep grooves.
Further inspection revealed that the rotor and stator windings were covered in a layer of dirt and oil.
Looking at the situation I realized that because the flex pipe was missing, oil mist and dirt were being sucked up into the alternator. Once inside, the oil and dirt became a sort of lapping coupound which caused the slip ring grooving and excessive brush wear.
Luckily I have a spare voltage regulator, but I am having some difficulty finding a shop that can repair the slip rings, which may force me to replace an other wise "good" alternator.
So, a word to the wise: Make sure that flex pipe is in place!
06-19-2004, 06:53 AM
#3
Race Director
I had to remove my pipe and rear plastic shroud, because it wouldn't fit after I relocated the alternator with the A/C delete kit. What do cars that come from the factory with A/C delete have? I looked on PET and didn't see a different part# for another shroud that would fit. Any ideas?
06-19-2004, 08:41 AM
#4
Three Wheelin'
Thread Starter
It depends on where the alternator is after you delete the A/C. I'd have to physically look at your car before I could even begin to think of an idea, but where ther's a will, there's a way.
06-19-2004, 12:09 PM
#6
Nordschleife Master
Cliff, are you sure those slip rings don't come off? I know they do on many delcos and you can just buy replacements. I haven't looked at our Bosch alternators close enough with that in mind but you may want to.
tifo, I know there are two styles of plastic shrouds for the back of the alternator. One is cone shaped and sticks out rather far which must be the one you have. The other is shaped like a very short walled pan - this one may work for you. I have actually seen one of these before so I know they exist. Where to find them is another matter. Guess talk to the Porsche parts department but even they sometimes have a hard time sorting through PET even if they know what they are looking for.
tifo, I know there are two styles of plastic shrouds for the back of the alternator. One is cone shaped and sticks out rather far which must be the one you have. The other is shaped like a very short walled pan - this one may work for you. I have actually seen one of these before so I know they exist. Where to find them is another matter. Guess talk to the Porsche parts department but even they sometimes have a hard time sorting through PET even if they know what they are looking for.
06-19-2004, 02:40 PM
#7
Three Wheelin'
Thread Starter
To be quite honest I haven't really looked but it would not suprise me.
I wanted to get them truned because other than the wear, the rotor is in real good condition. In fact, I suspect the alternator was rebuilt at some point because the color of the varnish on the rotor does not match the varnish on the stator windings.
The only issue I have with turning the slip rings is the increase in slip ring to brush box gap, which under some conditions can lead to premature brush wear/failure.
Anyway, by going to a local rebuild shop I can get much better service than if I were to hop over to AutoZone and plunk down 200 clams.
Another plus for using a local shop is that some times you can barter, and since I just happen to have a spare stator winding/diode block for an early 90 amp alternator with less than 1 hour of run time, I may just be able to get my rotor fixed for free.
I wanted to get them truned because other than the wear, the rotor is in real good condition. In fact, I suspect the alternator was rebuilt at some point because the color of the varnish on the rotor does not match the varnish on the stator windings.
The only issue I have with turning the slip rings is the increase in slip ring to brush box gap, which under some conditions can lead to premature brush wear/failure.
Anyway, by going to a local rebuild shop I can get much better service than if I were to hop over to AutoZone and plunk down 200 clams.
Another plus for using a local shop is that some times you can barter, and since I just happen to have a spare stator winding/diode block for an early 90 amp alternator with less than 1 hour of run time, I may just be able to get my rotor fixed for free.
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06-19-2004, 08:45 PM
#8
Race Director
Yeah, the one I had was the long cone-shaped one which is the one I have always seen. The alternator is now where the A/C compressor used to be, it uses the A/C compressor belt-tensioning barrell now. I really thought that the shroud was just for cooling, so I didn't worry about removing it as it is now located down lower and has better airflow than before. My car has abosolutely no fluid leaks what-so-ever, but maybe I need to be on the lookout for someone on the PCGB forum that is parting out a GB-spec car that doesn't have A/C.