Hi all - first post on JeepForum. I'm beginning to suspect I'll be spending a lot of time in here...
Changed my alternator today - 2008 WK diesel. Now you gotta understand, I've done much of my own car-work for the last 40 years; never rebuilt a transmission or steering box or did gears, but just about everything else. This job ranked 'way down there among the most unpleasant jobs I've done, alongside changing transfer cases in my '93 Cherokee; put the 'better' transfer case (the one with full-time 4WD) in, and I admit to being sneakily impressed with the lengths they went-to to hide the bolts
A couple tools you'll need (or really really want) to do this job:
- a 17mm twelve-point short socket (all mine were 6-point, natch), with a flip-head ratchet or breaker bar at least a foot long for it; much longer, the handle will argue with stuff. The socket is to turn the fan belt tensioner to loosen the belt; the tensioner has a twelve-point head cast into the bottom of it. You'll be turning it counter-clockwise; and this is why you want a bit of 'flip' to the head, because you'll be steering the handle around hoses 'n stuff;
- a 13mm ratcheting-wrench, preferably with a flip-head too - but not too sloppy a head. The bottom back bolt is as near-to-impossible to turn as anything I've ever fought with; you can get a 3/8" drive ratchet on it, but on the bottom back bolt and both of the top bolts, if you loosen them with a ratchet, the bolts will push your ratchet into the frame before they're loose enough to turn by hand. For the amount of pain involved in getting-at that bottom back bolt, it would be well worth your while to flag-down the Snap-On truck and buy yourself a premium new wrench;
- A drain bucket with a good pour spout, to drain the cooling system. I found the job simply impossible without removing the bottom rad hose;
- a 10mm female star-head socket and a good torx screwdriver, to remove the EGR throttle valve. I removed the black plastic housing; it has three star-head bolts and one very long torx screw. Be VERY VERY VERY careful with that housing - there's a wire that plugs into the back of it, I unclipped it and pulled on the connector, and out came what looks suspiciously like a MAF sensor. Now everything I've ever read about MAF sensors said that they're horribly easy to wreck and dreadfully expensive to replace. Don't know if I wrecked this one, my 'check-engine' light was already on for a bum sensor somewhere else, but the Jeep is running just great with the new alternator so I hope not; and
- if you live up here in the snowy North, or anywhere rusting is a problem, a spray can of rustproofing. The lines to the rack-and-pinion steering unit are rusted to chunky on my WK, and I can see I'll be doing them soon - one more place where the undercoaters never think to spray.
A few other tips:
- you'll need easy access to both above and below the front of the engine. Half the job is getting at the bottom back bolt, and I can't imagine how you'd get at it from the top. If you're left-handed like me, bring along a right-handed friend who owes you several beers; you'll owe him after the job.
- the alternator comes-out upward, in front of the engine - and flip it upside-down so the pulley points backward, because the hardest part of getting it out is clearing the mounts where it bolts-onto the engine; having the pulley back there makes it a lot easier to clear. When you put the new alternator in, put it in upside-down and backwards, i.e., the bolt where the main power wire attaches points downward before you flip it into position. And while you're flipping it, put all the bolts (generously smeared with anti-seize) in before you lift the alternator into place, it's a royal pain trying to get the bolts into the holes because the frame is in the way. And while I think to mention it, make sure the clip-on wire plug to the voltage regulator don't sneak itself in between the alternator and the engine while you're bolting the alternator in, or you'll get to unbolt it all over again.
- finally, don't be dumb like I was; don't start the job at 8:00 A.M. when you have to be at work by 3:00 that afternoon. Trust me!