Alternator bearing replacement help
#1
Pro
Thread Starter
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Can someone point me to a diy how to replace the alternator bearing? I can't get the search engine to show anything relavent. thx
#4
Three Wheelin'
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Have heard mention of it but ended up just replacing my alt along with the fan bearing when I had that beast out. It wasn't apparent to me and didn't see worth the trouble.
dave
dave
#6
Three Wheelin'
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Fan bearing is replaceable.
Fairly simple, I used a slide hammer/puller to get it on/off. Kind of nerve racking banging on that new bearing; tried to arrange it so I was acting on the inner (nearest the shaft) side of the bearing.
Been on there for 20K miles and working fine.
dave
Fairly simple, I used a slide hammer/puller to get it on/off. Kind of nerve racking banging on that new bearing; tried to arrange it so I was acting on the inner (nearest the shaft) side of the bearing.
Been on there for 20K miles and working fine.
dave
#7
Rennlist Member
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Mark, the bearing replacement is the easiest part of the job, obtaining a bearing will be a job unless you have one already. good luck!! please post if you have or find a source for them.
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#10
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All us parts guys have the RS fan hub adapter. As to the alternator, a rebuilt one is only $275 or so. While a bearing would only be a few $$$s, the time to futz with it would be prohibitive by most shops.
#11
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Mark,
I would think it is more likely that you have to replace a fan bearing than an alternator bearing. The fan bearing (either rs or oem) are readliy available and relatively cheap. There is a DIY on http://p-car.com/diy/diy.html
There are several ways to go about it. I was able to remove the fan and bearing while the alternator was left in the car (waaayy easier) using a puller (see photos below) Some people are nervous about using a puller on the fan since the fan is made of magnesium. I talked to several porsche wrenches and they assured me this was OK.
Getting the bearing back into the fan is tough if you don't have a press. I had access to a press so I was able to do it this way.
Someone recommended freezing the bearing overnight and then heating up the fan (be careful with this) and then the bearing should slide in. I didn't have any luck with this approach. This is not for the faint at heart.
The photos below are of the gear puller I got at Harbor Freight (no afflitiation, blah, blah, blah) I had to use a bolt and nut to replace the screw mechanisim that came with the puller and this worked fine. Again, getting the new one in is harder than getting the old one out. Best of luck!
BTW, I asked the dealer to quote me a repair price and I think it was over $900
Picture1 is the puller attached to fan after I modified puller
Pictures 2 & 3 are of the puller set I bought (cheap!)
Picture 4 is puller as it came out of the box
Picture 5 is puller after I removed original screw and replaced with bolt & nut
I would think it is more likely that you have to replace a fan bearing than an alternator bearing. The fan bearing (either rs or oem) are readliy available and relatively cheap. There is a DIY on http://p-car.com/diy/diy.html
There are several ways to go about it. I was able to remove the fan and bearing while the alternator was left in the car (waaayy easier) using a puller (see photos below) Some people are nervous about using a puller on the fan since the fan is made of magnesium. I talked to several porsche wrenches and they assured me this was OK.
Getting the bearing back into the fan is tough if you don't have a press. I had access to a press so I was able to do it this way.
Someone recommended freezing the bearing overnight and then heating up the fan (be careful with this) and then the bearing should slide in. I didn't have any luck with this approach. This is not for the faint at heart.
The photos below are of the gear puller I got at Harbor Freight (no afflitiation, blah, blah, blah) I had to use a bolt and nut to replace the screw mechanisim that came with the puller and this worked fine. Again, getting the new one in is harder than getting the old one out. Best of luck!
BTW, I asked the dealer to quote me a repair price and I think it was over $900
Picture1 is the puller attached to fan after I modified puller
Pictures 2 & 3 are of the puller set I bought (cheap!)
Picture 4 is puller as it came out of the box
Picture 5 is puller after I removed original screw and replaced with bolt & nut
#12
Rennlist Member
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Good info on the fan bearing...
The rear alt bearing can also be replaced but only worth it as a DIY or a really reasonably priced shop, as Bob said above.
Pulling the rear bearing from the alt shaft takes a $20 tool.
If you are doing this, I'd replace the regulator/brush assembly also. As long as the armature and windings are good, you would then have a rebuilt alternator. You can also easily clean up the armature.
If you need the rear alt bearing part #, let me know and I will dig it up. I posted this here before but the search engine is fubar. They are about $10 and that includes shipping.
The rear alt bearing can also be replaced but only worth it as a DIY or a really reasonably priced shop, as Bob said above.
Pulling the rear bearing from the alt shaft takes a $20 tool.
If you are doing this, I'd replace the regulator/brush assembly also. As long as the armature and windings are good, you would then have a rebuilt alternator. You can also easily clean up the armature.
If you need the rear alt bearing part #, let me know and I will dig it up. I posted this here before but the search engine is fubar. They are about $10 and that includes shipping.
#14
Rennlist Member
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mark, which bearing are you replacing alt or fan?
a year or so ago i tried the to obtain the fan bearing it was non obtainable thru porsche or any bearing outlet for that matter. see several threads on this. the shortage of bearings and the rediculous belt shimming design drove a lot of people to the RS hub adapter. Viper Bob sells them if you decide to go that route.
Luft Kuhler what is the part number and outlet that you found a bearing? 964.106.051.30??
a year or so ago i tried the to obtain the fan bearing it was non obtainable thru porsche or any bearing outlet for that matter. see several threads on this. the shortage of bearings and the rediculous belt shimming design drove a lot of people to the RS hub adapter. Viper Bob sells them if you decide to go that route.
Luft Kuhler what is the part number and outlet that you found a bearing? 964.106.051.30??