Alternator Install help!

[Innov8]

Need you help. I am replacing my alternator (82 SC), and I was able to disassemble without problems except:

1. the ground strap to the engine, The insulation is cracked and the wire strands look very aged and brittle. I would like to replace it but I am concerned about backing off the nut on the corner of the engine case... the bolt is rusted and I soaked it with PB blaster but don't want to break the stud. Any suggestions...? Is replacing a ground wire that looks old but could be functional worth the risk of breaking an engine stud or am I just overly concerned?

2. The reassemble of the fan onto the shaft of the alternator: the 'wood-ring' (I think is called) keeps popping out as I slide the fan down the shaft. I've spent 30 minutes doing this over and over and I figure I must be doing something wrong. What is the trick to get the fan onto the shaft with this guide in place?

I'm stuck. Thanks.

[Walter_Middie]

I think you're asking about the woodruff key.

woodruff key - Google Search

I usually tip the key slightly so that that it just barely slides under the fan. Once started, it should straighten up as the fan is pressed on.

[LUFTMAN]

sometimes the ground wire looks bad but still works. take a ohmeter and measure the resistance the wire has between wire eyelet and bolt on engine case. the lower the number the better. scrub bolt at engine case with a wire brush. apply some heat with a butane solder torch (home depot,lowes etc.) get it hot nylock plastic in nut will melt. try again to loosen should break loose. replace nut. as for alt. key take a center punch and stake both side of the key. 3 times on each side this will raise the metal. then tap key into altenator shaft. put a little antisieze on inside of fan assy. before you install fan should slide on with no problem without rolling up the key. good luck best regards tom

[al lkosmal]

A good ground is essential. While you have everything out is the time to fix this stuff. Soak it over night....heat it up...I use a small propane torch....try to remove it.....soak it....heat it up...try to remove it....the heat is the trick....if that doesn't work....do it again.

Regards,

al

PS: I use the patented and approved, Rex method, for woodruff key orientation, prior to fan installation.

[Joe Bob]

Tighten the nut a bit THEN loosen. On the woodruff key, a little dab of lube helps. Also look for any burrs on it. Old guys can use a magnifying glass...I won't tell. A little emery cloth can clean it up.

[Wil Ferch]

Oftentimes a woodruff key needs to have a slight "interference" fit. You can "distress" the key by trying to gently "peen" a portion with an old screwdriver blade or such... behind a gentle whack of the hammer...or maybe just a sacrificial small piece of tape around the key will make it fit "Snug". Once it's in-place between the 2 mating pieces, any further degradation of the tape is irrelevent.

[Innov8]

Thanks everyone. Tested the ground wire tonight and at first it seemed OK... reading of .05 on the ohm meter. Then I moved the wire into the position that it would be when everything was put back into place and the reading started jumping around erratically—just like my tach was doing! Anyway, I wasn't able to finish the project just yet. I need to pick-up the wire and fittings to make a need ground wire. Can anyone advise on the torque settings for the engine nut when I put it all back together...and should I use thread lock?

Tomorrow, I hope to get it all assembled and see if the new alt (and ground strap) have cured the jumping tach. Thank you again. Patrick

[Innov8]

Update: I replaced the alternator, cap, rotor and plugs this morning. The car was hard-starting but I figured it was because it had been sitting for more than 6 weeks. Eventually (8-10th crank), the engine caught and idled nicely... BUT there was an unsettling, tin knocking sound occasionally and uneven...I immediately turned off the engine. I check around the floor making sure I had put everything back together...no extra parts, etc. Started the car up again and idled smoothly no sound---great, but then it came back. At first about every 20 seconds and then, progressing to about every 10 seconds but not in a regular pattern. It sort of sounds like a tin can being it with a screw driver...it seems to come from the top of the engine but can't tell if it is the right or left side. Does this sound like I need a valve adjustment or something else?

Thank you for your advice.

[Innov8]

Forgot to mention that when I give a little gas, the engine bogs down and backfires. I assume that the next step is valve adjustment. This hasn't been done in the 5k miles or 5.5 years that I owned the car but the PO stated that it was done 'about' 5k prior to my purchase. Prior to this, the car ran fine and always started right up. Do the valves loose their tolerances that quickly?

Your advice is much appreciated. Thank you. Patrick

[Innov8]

Lastly, Wil—the tape on the woodruff key was the perfect solution.
Joe—the tighten, then loosen worked as well...didn't need the heat. Hopefully, the new Alt and VR and ground wire will eliminate the jumpy tach. As soon as I get the engine running smoothly, I'll be able to confirm if this was the fix. Thanks

[Drisump]

No, according to Porsche, the valves need adjusting every 15K( that's assuming they were done properly before....?). In any case, the sound you describe doesn't sound like a valve adjustment problem, is there something slightly interfering with the fan? Was the engine bogging before the work was done? If not, I would retrace my tracks, cheers.

[Innov8]

thx Drisump, the engine did bog before I changed the alt. basically, the car was caught out in the rain for two days and has been running roughly (hard start, poor idle, bogs under and repeated backfiring when given gas) since then. Concurrently, I started to notice that the tach was getting jumpy so I assumed the misfiring was related to an alt issue. I replaced the alt, the alt ground strap, new cap and rotor and fresh plugs. At this time, I did not notice any tinny noise but the car would bog down and back fire when pressing the go pedal.

After replacing the alt and ground strap, I tried starting the car to see if that along was the problem (hoping to isolate) but it did start after 5 tries so I went on to replace the the cap, rotor and the plugs. All the plugs had carbon but the plugs on 4-6 where wet with what I assume was fuel. 1-3 plugs were dry. I am assuming that the issue is still ignition but when I heard the noise I started to worry about the valves.

Now that the plugs have been out of the engine for 12 hours, I am about to re-inspect them for any telling signs. What else would you recommend? I spun the fan looking to see if I would replicate the sound--no luck. Rotates freely and quietly.

Don't know where to look next. ?

[Wil Ferch]

Check all grounds again....the hint is the jumping tach. Also make sure the fan housing is put back absolutely square and perpendicular, there is a small "pin" that fits the fan housing recess at 6 0'clock and it needs to "sit" perfectly there. You might want to see if by removing the fan belt you can "freely" turn the fan without a scraping sound. Also make sure the fan pulley "halves" are properly put together, and that you are using 6 shims (total), with whatever number you need *between* the pulley halves for the required belt tightness...and the remaining number ( to total 6) placed under the retaining nut on the outside of the external pulley half.