iarnstein

Hi Irwin here. Bit of a mechanical nerd so I thought I'd take time to help. Used to post on stovebolt a great deal and moderate a forum on that site which is for old chevy trucks. Anyhoo....

Alternator replacement/Rebuild....

I recently got a 2000 LS400 with low miles and it was hardly driven. The car only had a discharge problem (not indicated ever by the battery light) once the alternator had warmed up. The previous owners did not discover it because they only took short trips and the car would charge itself up adequately. However an all day trip for me resulted in a dead car.

I got friend to take me home and returned with a battery from my truck. Car started up just fine and showed 14.5 volts on meter. I thought, hmm, mebe battery bad (even though new 7/14). Once I got home tho battery at 11.5 volts so ok, fix alternator.

Undo the battery first - usually don't mess with that, but on an electoral repair, do it.

take the power steering pump pulley off after you've removed the serpentine belt. Mine was fairly easy with just sticking an old king pin in the pulley and gently torqueing up on the bolt. Pulley then slid off with minimal prying. I put anti'sieze paste on the shaft so if I had to get to it again, it would be just as easy. The pulley sits in front of the alternator so you can get the alt off with the pulley in the way. :P

now jack it up and put it on stands because you get to the alt from the bottom of the car and use a drill driver on low torque to whip off the 10 mm bolts holding on the belly pan/lower engine cover. Once that is gone, you'll have to loosen an oil line held on with two bolts (12mm) at the corner of the oil pan and

One nut high on stud and one bolt low and the alternator comes out. (14mm) Or at least gets loose. Unplug the control harness and unbolt the power lead. You then have to ****** the alternator out past the loosened oil line but its fairly easy once you figure out. Its a tight fit.

Did not buy a new one or a parts house cheapo. Instead took it to Hammond Bros in garland texas and they rebuilt it in 1 hour. bearings needed doing too.

Having read up on these things and having had a 90 ls400 that had a power steering leak, I did an old motorcycle racer trick and safety wired a bread loaf tin (foil) (small) to the power steering pump as mine was not leaking (figured I have to fix that and it had caused the problem, but everything was bone dry). Since this is a known issue, the tin catches any leaks and channels them towards the back of the car away from the alternator. After that I put new wire looms on the harness that just had black tape on it and stuffed the alternator back in. Hook it up, bolt it down, put the power steering pump pulley on, drive belt back on and done. Twice as hard as an old chevy, but not to say its hard.





note lower right corner where the loosened line is. bread foil tin is safety wired to ps pump. in bike racing we'd safety wire turkey basters to the bottom of the engine in vintage class so if a rod let loose, the oil would be caught and not put everyone else in danger on the track. to the left of the tin is the stud that holds the alternator on.

figured as long as I was under the car, might as well prevent a future possible issue.