Alternator repair/replace?
10-18-2012, 01:56 AM
#1
Rennlist Member
Thread Starter
Alternator repair/replace?
Help me, Obi-Rennlist, you're my only hope ...
I've had some drama this week with full scale electrical failures stranding me roadside. I replaced the battery, which was quite old and due for replacement anyway, but that did not solve the problem. Two days later, once again the ABS and airbag lights lit up, the radio quit, the speedometer flopped all over, and eventually the engine chugged to a halt. Based on this behavior and what I've read, I'm guessing this is an alternator issue.
I have done a lot of reading through old threads and I think I have a basic grasp on what it would take to extract the alternator, but I want to be sure that is what I should do before I tackle the job. Some data: voltage at the battery at rest is about 11.5, but when running, the car drops to 10v with no load, and sinks to 8 (and falling) with lights, radio and A/C on. The belts are intact.
The question: I understand the voltage regulator/brushes assembly can be swapped out, although the amount of engine disassembly seems to be about the same as it would be to simply replace the alternator. Is there any way to determine whether the entire alternator must be replaced rather than just the voltage regulator?
(I feel like I'm using the right words, but if I'm getting some of the concepts wrong, please set me straight. It's like walking around Uzbekistan with a Berlitz phrase book; thanks to this forum I believe I understand some of the concepts, but I'm afraid I don't know what I don't know.)
BTW, a word to the wise: make sure your tool kit includes the tow hook.
I've had some drama this week with full scale electrical failures stranding me roadside. I replaced the battery, which was quite old and due for replacement anyway, but that did not solve the problem. Two days later, once again the ABS and airbag lights lit up, the radio quit, the speedometer flopped all over, and eventually the engine chugged to a halt. Based on this behavior and what I've read, I'm guessing this is an alternator issue.
I have done a lot of reading through old threads and I think I have a basic grasp on what it would take to extract the alternator, but I want to be sure that is what I should do before I tackle the job. Some data: voltage at the battery at rest is about 11.5, but when running, the car drops to 10v with no load, and sinks to 8 (and falling) with lights, radio and A/C on. The belts are intact.
The question: I understand the voltage regulator/brushes assembly can be swapped out, although the amount of engine disassembly seems to be about the same as it would be to simply replace the alternator. Is there any way to determine whether the entire alternator must be replaced rather than just the voltage regulator?
(I feel like I'm using the right words, but if I'm getting some of the concepts wrong, please set me straight. It's like walking around Uzbekistan with a Berlitz phrase book; thanks to this forum I believe I understand some of the concepts, but I'm afraid I don't know what I don't know.)
BTW, a word to the wise: make sure your tool kit includes the tow hook.
10-18-2012, 03:32 AM
#2
I feel once a part of the alternator goes the rest is not far behind. I had my alternator rebuilt by a local electric motor shop and it looks great with stable voltage across the rpm range. The alternator has to come out for any access to it's parts.
10-18-2012, 05:06 AM
#3
Drifting
Help me, Obi-Rennlist, you're my only hope ...
....Two days later, once again the ABS and airbag lights lit up, the radio quit, the speedometer flopped all over, and eventually the engine chugged to a halt. Based on this behavior and what I've read, I'm guessing this is an alternator issue.
....
The question: I understand the voltage regulator/brushes assembly can be swapped out, although the amount of engine disassembly seems to be about the same as it would be to simply replace the alternator. Is there any way to determine whether the entire alternator must be replaced rather than just the voltage regulator?
....Two days later, once again the ABS and airbag lights lit up, the radio quit, the speedometer flopped all over, and eventually the engine chugged to a halt. Based on this behavior and what I've read, I'm guessing this is an alternator issue.
....
The question: I understand the voltage regulator/brushes assembly can be swapped out, although the amount of engine disassembly seems to be about the same as it would be to simply replace the alternator. Is there any way to determine whether the entire alternator must be replaced rather than just the voltage regulator?
You can just swap out the regulator which has the brushes attached. When I pulled mine, it really looked like the copper sleeves on the shaft the brushes ride on were worn, however I didn't stare at it too long. I took it all to the local alternator rebuild shop and they rebuilt it for about $110. A remanufactured one from Pelican was $260 recently (after you return your core). So the local rebuild is a great way to go. Oh, and you do NOT want to know what a new alternator costs.......ok, since you asked....new it was somewhere north of $650 from Sunset, who normally has the best pricing. Stupid expensive. Just rebuild it or get a reman unit. See if they replace both the front and back bearings when they do the rebuild, since you don't want to pull it apart again soon.
(I'd like to say all went easily, but due to my dumb @ss nature during reinstall, I've done several rounds of in/out, repeat.... (however, not the fun version of that...
) NOTHING you have to worry about, as I turned it into a rebuild+newFan+shroudPainting extravaganza, then screwed up.....just don't use a big hammer on stuff. Oh, and don't leave a rag laying on the rear bumper to be pulled into the fan/belts....big bang and broken belts are the result. A learning experience. On the plus side, I can have the belts off in <15 minutes with my new found experience. 
One day, that fun will get its own thread, but I'm too scarred right now to do it.... 
)Info you'll need:
http://www.pcarworkshop.com/index.ph...or_Replacement
Everything is pretty straight forward and easy. Take your time, remember where everything was (I like the magnetic trays for holding all the parts), have a magnetic picker-upper to chase down dropped items, a super long flat-bladed screwdriver is helpful for putting the belts back on...getting them over the crankshaft pulley. And a good 12pt triple square socket.
The hardest part is getting the back cover & 3 wires off/on the alternator. Getting the fan and fan bearing off the shaft wasn't the easiest either, but penetrating oil and patience rules the day.....I used a puller, but the method of 3 long threaded bolts thru the holes and pushing on the housing to extract the fan+bearing seems like a really good way to go (search RL for that) and I'd attempt that first next time I do one of these.
Best of luck!
Last edited by kjr914; 10-18-2012 at 08:35 PM.
10-18-2012, 05:20 AM
#4
Race Car
+2 on getting a local rebuild. The regulator and brushes are like $30 and the bearings not much more.
Then you know you have a genuine unit with good build quality.
Then you know you have a genuine unit with good build quality.
10-18-2012, 07:45 AM
#5
Rennlist Member
The alternator must come out in any event - and your new battery placed on a charger. If this is to be a DIY , then it is no big deal to carry on and replace the regulator/brush set, which is the more likely area of failure ....... matter of fact, if you go that route, it is not even necessary to pull the fan & bearing off the alternator shaft.
Once the belts are off, spin the alt shaft: one can generally tell if the bearings are OK by sound and feel. The brushes cause some drag & noise, but that can be eliminated once they are removed when the alternator/fan is sitting on the bench. Unless the belts were way too tight, or the car has a lot of mileage, odds are that the bearings are fine.
Install a new reg. assembly & motor on ....
Failures of diodes, etc within the alternator are far more rare, and will require a rebuild; however, most only need the $25 swap of the regulator.
Once the belts are off, spin the alt shaft: one can generally tell if the bearings are OK by sound and feel. The brushes cause some drag & noise, but that can be eliminated once they are removed when the alternator/fan is sitting on the bench. Unless the belts were way too tight, or the car has a lot of mileage, odds are that the bearings are fine.
Install a new reg. assembly & motor on ....
Failures of diodes, etc within the alternator are far more rare, and will require a rebuild; however, most only need the $25 swap of the regulator.
10-18-2012, 02:02 PM
#6
Rennlist Member
Thread Starter
Many thanks, gents (and to those on the many other related threads I found through searching). I think I have what I need to make an informed decision about the next steps. All I need now is to watch another 50 hours or so of Wheeler Dealers in the hope of picking up Edd China's wrenching skills by osmosis.
10-18-2012, 02:28 PM
#7
Drifting
Trending Topics
10-18-2012, 08:33 PM
#9
Drifting
One thing to be careful of....there are two different alternator to fan bearing spacer sizes due to 2 slightly different alternator housings (different on side facing rearward in the car).
Make sure you get the 2 correct pieces together, otherwise the fan will bang on the alternator housing when spun by hand. Sadly, I know of which I speak....
Make sure you get the 2 correct pieces together, otherwise the fan will bang on the alternator housing when spun by hand. Sadly, I know of which I speak....
10-19-2012, 12:45 AM
#10
Rennlist Member
If you had an on-board voltmeter, you'd know. 
If you decide to tackle this, make sure the first thing you do is disconnect the battery.
Rebuilds in the vast majority of cases are sub-standard at best. They simply take short cuts like turning down the rotor's slip rings instead of installing new slip rings. They're not that thick to start with.
The stator and its windings; not much can go wrong. The diode pack, same.
The bearings, slip rings and voltage regulator are what go in most cases.
Our alternators are in a hotter environment than most. You want to make sure they use bearings that meet the requirements. I came across WBD Bearings that I'll be going with when the time comes.
If you decide to tackle this, make sure the first thing you do is disconnect the battery.
Rebuilds in the vast majority of cases are sub-standard at best. They simply take short cuts like turning down the rotor's slip rings instead of installing new slip rings. They're not that thick to start with.
The stator and its windings; not much can go wrong. The diode pack, same.
The bearings, slip rings and voltage regulator are what go in most cases.
Our alternators are in a hotter environment than most. You want to make sure they use bearings that meet the requirements. I came across WBD Bearings that I'll be going with when the time comes.
12-19-2012, 12:45 PM
#11
Rennlist Member
Thread Starter
I've mended something!
After far too much downtime due to other responsibilities, buying parts, buying tools, buying new tools to add to the tools I bought before that were the wrong size, and buying additional parts to supplement the parts that I was afraid I would ruin in figuring out how to do the repairs in the first place, I did at last manage to replace the voltage regulator in my alternator. Even better, the car actually works now, so it was the correct repair. I replaced the belts while in there.
The new regulator and the old (observe the difference in the brushes):
A couple of thoughts for the benefit of future thread-searchers:
The writeups on PCarWorkshop for both the alternator removal and belt replacement get the job done -- thanks, Robin Sun and others who put together these essential resource materials.
The fan pulley bolts are absurdly soft; buy extras.
The nut for the driver's side forward bolt for the AC is stupidly difficult to replace. I needed to use a bendy grabbing tool and a lot of time to get the nut into proper orientation for the bolt to catch.
An extendable magnet tool is absolutely essential.
It is not necessary to disengage the alternator from the fan to replace the voltage regulator, saving a lot of effort and, in my case, potential damage to parts that were fine before I started messing with them.
It was so satisfying to fire the car back up after it sat sadly idle in the garage for weeks and see that everything worked as it should: no clanks, bangs, shakes or warning lights. More proof that even the inexperienced can wield a wrench with something resembling competence, when given the right guidance.
After far too much downtime due to other responsibilities, buying parts, buying tools, buying new tools to add to the tools I bought before that were the wrong size, and buying additional parts to supplement the parts that I was afraid I would ruin in figuring out how to do the repairs in the first place, I did at last manage to replace the voltage regulator in my alternator. Even better, the car actually works now, so it was the correct repair. I replaced the belts while in there.
The new regulator and the old (observe the difference in the brushes):
A couple of thoughts for the benefit of future thread-searchers:
The writeups on PCarWorkshop for both the alternator removal and belt replacement get the job done -- thanks, Robin Sun and others who put together these essential resource materials.
The fan pulley bolts are absurdly soft; buy extras.
The nut for the driver's side forward bolt for the AC is stupidly difficult to replace. I needed to use a bendy grabbing tool and a lot of time to get the nut into proper orientation for the bolt to catch.
An extendable magnet tool is absolutely essential.
It is not necessary to disengage the alternator from the fan to replace the voltage regulator, saving a lot of effort and, in my case, potential damage to parts that were fine before I started messing with them.
It was so satisfying to fire the car back up after it sat sadly idle in the garage for weeks and see that everything worked as it should: no clanks, bangs, shakes or warning lights. More proof that even the inexperienced can wield a wrench with something resembling competence, when given the right guidance.
12-19-2012, 02:58 PM
#14
Rennlist Member
Thread Starter
Brakes, and maybe suspension (I dream big). The one thing I have no desire to touch are the engine internals. Leave that to the experts with the proper tools and experience.
Also, I did manage to screw up my radio by putting in the wrong security code. Gotta sort that one out now.
Also, I did manage to screw up my radio by putting in the wrong security code. Gotta sort that one out now.
