benhavilland

Job:
Replace alternator on Betty, my 1976 Ford F350 Super Camper Special

Reason:
One on truck was about 30 years old.  I just got a new battery so it seemed like a good time for this job.

Time used:
About 30 mins

Method:
Take note of previous alternator placement & wiring.  Remove old alternator (2 bolts).  Exchange wiring, install new alternator and set at proper tension.  Test.

Notes:
I picked up this rebuilt alternator at Checker for about $40.   It came with life time warranty and I got a core value back on it of like $11 or $12.  I took a lot of photos, maybe too many for this job, but hopefully they will be of use to somebody reading this.  Some photos have notes attached via Flickr that you will see when you click on them.

Remember to save everything you remove like any nuts, bolts etc. and remember where they came from. You will need them when you put the new part in.  You may want to take photos or make a sketch of what was removed.

The new Autolite alternator:

Side view

Back view, wiring connections

The old Alternator:

Top view, click to see captions

The first step is to loosen the top bolt.  Just get it loose, don’t remove the whole thing yet.  This will allow the alternator to swing free when we do step 2.  I did this from above the engine but it could also be done from underneath.

Top bolt and belts, click to see captions

Bottom view, shows bottom bolt and block for tensioning, click to see captions

Second step is to loosen and then remove the bottom bolt, which also applies tension to the belt.  To be safe just slowly loosen it a little at first because the alternator will move a little because of the belt tension.  Once the bolt is lose and the alternator is able to swing around a little you can slip off the belt and then remove the bottom bolt entirely.

Now go back and remove the top bolt all of the way.  Make sure to hold on to the alternator when you do this because it is the last thing holding it in and it will fall if you don’t grab it.

Bottom view, showing tensioner block a little better, click to see captions

With all bolts removed I lined up the backs of the new and old alternators to make the wire moves.  With my battery disconnected I moved the 3 wires from the old alternator to the exact same places on the new alternator.

New on left, old on right, click to see detailed captions

As you can see, the belt connector pulley is different on the new one. The guy at Checker said that I could swap the old one if I needed to but I just used the inner ring on the new one and it worked perfectly.  I chose the inner ring by lining them up side by side and figuring out the best belt placement.

Side by side, old left, new right, click to see captions

Last step, install the new one. I installed the alternator by screwing in the top bolt first, almost tight but still allowing some movement.  I then screwed in the second bolt almost all of the way tight (the one that goes into the adjusting curved area).  After that I placed the belt around the alternator and engine pulley.  I then used the handle of the large pliers to act as a lever against the block where the screw attaches in the alternator.  You can use any strong, straight tool like a lug wrench or pry bar or something.  Pulling back the pliers I used applies tension to the belt.  Once proper tension was applied I tightened the adjuster bolt to set the alternator in place.  I then tightented the top bolt all of the way and then went back to the adjusting bolt to make sure it was all of the way tight.  Make sure to check your belt tension at this point and readjust if necessary.

This is the view of the alternator after it has been connected and tightened.  Job complete.

New alternator fully installed, top view

Once complete I fired up the truck, checked to voltmeter in the dash for power coming back and it looked good.  For a more accurate gauge of power coming back you could use a digital voltmeter ($15 bucks max for a basic one) on the battery to see voltage & amps returned to the battery when running vs when off.

All of the tools that I used. Click on the photo to see the tagged labels  via Flickr.

Tools, click to see captions/lables