Voltage spikes on '88 911
#16
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ontario: I know the drop technique sounds a little scary, but I've done about 500 alternators that way! Also, at 129K miles this will probably be your car's third alt. rebuild, at the very least its second. At my shop Carrera alternators had a typical life expectancy of between 40-50K miles, it's possible that the first rebuild was a very good one, and that unit outlived the original.
And no, you're not imagining things, I've seen quite a few alternators of your vintage, when the regulators fail, cause spikes to occur between 17 and 18v. We've had customers call from the road with bouncing tachs, glitching stereos, rotten egg smell filling the cab, and some we told, based on their symptoms, to park the car and call a tow truck.
And no, you're not imagining things, I've seen quite a few alternators of your vintage, when the regulators fail, cause spikes to occur between 17 and 18v. We've had customers call from the road with bouncing tachs, glitching stereos, rotten egg smell filling the cab, and some we told, based on their symptoms, to park the car and call a tow truck.
#17
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Which way does the alternator come out? Does it come out through the pully side or through the side with the electrical connections. And when you say to lightly grease the shaft, are you talking about the part where the pulley wheel attaches? The threaded part? Is that just to keep the pulley and nut from seizing?
#18
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It can only come out one way, the end opposite the pulley shaft seats against the cast housing.
"Grease the shaft" lightly on the non-threaded surface that the fan hub fits on.
"Grease the shaft" lightly on the non-threaded surface that the fan hub fits on.
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The drop trick worked and then some light taps on the shaft released the fan.
Now the big dilemma - polish the housing and fan or not? Paint it? Powder coat it?
This all started with replacing the amplifier. Now it's turning into one of those Russian nesting dolls.
Now the big dilemma - polish the housing and fan or not? Paint it? Powder coat it?
This all started with replacing the amplifier. Now it's turning into one of those Russian nesting dolls.
#20
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For info regarding doing some sort of finish on the fan & housing you will have to wait for someone else to offer their recommendations. I know stock is not as pretty as it can be, but back when I sold my shop available finishes had trouble with blade clearance, and the actual finish was not a long-life deal, so I never got involved with it. A number of people on this forum have done their fan, hopefully a few will chime in and offer their experience.
Glad that you got it apart OK! When you get the rebuild back, be sure that the gray air funnel fits over the regulator. There are two sizes, both OK, but you might have to modify the funnel slightly to fit over the back of the alt properly.
Glad that you got it apart OK! When you get the rebuild back, be sure that the gray air funnel fits over the regulator. There are two sizes, both OK, but you might have to modify the funnel slightly to fit over the back of the alt properly.
Last edited by Peter Zimmermann; 04-11-2008 at 07:57 PM.
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Dang, I am having a hard time getting this thing back in. The fins keep hitting something in the back. I thought I bent them back to the proper position but now the lower fin is hitting the grounding block on the engine case. Maybe I messed up the positioning of the air diverter. Anyone know where there is a photo that shows clearly where these fins attach?
#24
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Mine is an SC it is true the shroud only goed one way . but it should only fit one way anyway on the regulator and alternator. Where are you Ontario. If oyur close I could give you a hand. I don't think these [ics show you what you need though
Last edited by theiceman; 01-09-2013 at 10:14 AM.
#25
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I had head lite fluxing and replaced the voltage regulator. I had tapped my housing off using a 1/2" brass rod. Alum should do also. Going back on I heated the housing in the oven and left the alt in the freezer over night. It fell right in. I had a cheap volt reg 1st trip and did the job twice. I suggest using the-- Peter Principal--- Zimmerman Zinger. Use factory stuff as in the buying of the regulator.
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Jake:
Honestly, I have no idea what you are saying. But, I like the Alfa in your signature.
I took a lot of photos during the disassembly instead of marking the pieces. Mistake. When I look at the photos now, they don't make as much sense as I thought. But, I took a good look at the pics and at Dempsey's 101 book and I think I have it figured out.
I'm taking a break though and I will tackle it tomorrow morning. My hands are killing me from shoving them into the housing. That extra strut in the cabriolet is a real PITA.
Iceman, thanks a lot of the offer. I am in Etobicoke. If I can't get it together tomorrow, you might hear my cry for help. I'm not panicking yet. I've been in worse shape on previous jobs with old Alfas and BMWs. Only once have I suffered the ignominy of being towed to the shop.
Fingers are crossed.
Honestly, I have no idea what you are saying. But, I like the Alfa in your signature.
I took a lot of photos during the disassembly instead of marking the pieces. Mistake. When I look at the photos now, they don't make as much sense as I thought. But, I took a good look at the pics and at Dempsey's 101 book and I think I have it figured out.
I'm taking a break though and I will tackle it tomorrow morning. My hands are killing me from shoving them into the housing. That extra strut in the cabriolet is a real PITA.
Iceman, thanks a lot of the offer. I am in Etobicoke. If I can't get it together tomorrow, you might hear my cry for help. I'm not panicking yet. I've been in worse shape on previous jobs with old Alfas and BMWs. Only once have I suffered the ignominy of being towed to the shop.
Fingers are crossed.
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"Jake:
Honestly, I have no idea what you are saying. But, I like the Alfa in your signature"
Sorry about that. 1. Do not buy an after market voltage regulator, buy the factory/Porsche part(and make sure your builder does so if you have him do it. 2. When assembling 2 parts that are a close fit, you can expand the outer one with heat (oven) and shrink the inner one with cold (freezer) so that they go into each other easy, with a little grease of course. 3. Peter Zimmerman suggests all factory parts. It appears to be a good idea based upon heavy knowledge. Even factory fanbelts which fit the first time without adjusting the shims(the clutch cable made sense, but the fan belt astounded me).
If he posts, I try to read for knowledge.
Honestly, I have no idea what you are saying. But, I like the Alfa in your signature"
Sorry about that. 1. Do not buy an after market voltage regulator, buy the factory/Porsche part(and make sure your builder does so if you have him do it. 2. When assembling 2 parts that are a close fit, you can expand the outer one with heat (oven) and shrink the inner one with cold (freezer) so that they go into each other easy, with a little grease of course. 3. Peter Zimmerman suggests all factory parts. It appears to be a good idea based upon heavy knowledge. Even factory fanbelts which fit the first time without adjusting the shims(the clutch cable made sense, but the fan belt astounded me).
If he posts, I try to read for knowledge.
#28
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Ontario:
Did you get it all back together? I couldn't believe what a PITA the job was when I did mine. Anyhow, I have pics of my swap out if you need them- send me your email address.
Thanks,
Paul.
Did you get it all back together? I couldn't believe what a PITA the job was when I did mine. Anyhow, I have pics of my swap out if you need them- send me your email address.
Thanks,
Paul.
#29
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"Do not buy an after market voltage regulator,"
Best advice!!!!!! Remember, the regulator (an electronic device) "sees" the
very hot engine and those junk aftermarket regulators increase the alternator's
failure rate. Why save $10 - $20 on a junk regulator and get stranded somewhere?
Use an OEM Paris-Rhone regulator.
Also. it's VERY simple to remove ANY 911 alternator from its housing by using
a 2x6 (or 2X4) block and tapping the housing on the block with the alternator
pointing down as the housing is rotated during the tapping. There's NO need
to drop the housing & alternator!
Best advice!!!!!! Remember, the regulator (an electronic device) "sees" the
very hot engine and those junk aftermarket regulators increase the alternator's
failure rate. Why save $10 - $20 on a junk regulator and get stranded somewhere?
Use an OEM Paris-Rhone regulator.
Also. it's VERY simple to remove ANY 911 alternator from its housing by using
a 2x6 (or 2X4) block and tapping the housing on the block with the alternator
pointing down as the housing is rotated during the tapping. There's NO need
to drop the housing & alternator!
#30
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Loren, Loren, Loren - I said "gentle" drop. I didn't say climb to the top of a 10' step ladder and heave it at the wood blocks! An inch or two above the wood blocks is sufficient, so I guess "drop" might not be the best term - maybe accelerated tap would be better. Sheeeesh!