So, my experience with alternators is that they rarely fail. And if they do, it's because the brushes wear out or the regulators parts fail. Far less often, the bearings need to be replaced.

My 4.2 NA uses a Denso alternator, with a Jag price around $1K. You can get replacements from Denso for around $400 new, but more likely $250 or so with a unit rebuilt by Denso. There are Bosch replacements, but that's not the point.

Once you find out the model used, below is is a great source for rebuild parts. I've used these guys before. URL below takes you to parts kits, for around $40. Individual parts simlar.

https://www.maniacelectricmotors.com...-bearings.html

It also has all the cross reference numbers for major sources of the unit. There's a similar page for the other Jag alternators.

Alternators are really easy to fix or even rebuild if you want to. You can put in new brushes and regulator in 45 minutes, Sometimes you can do it on the car if you can reach the back of the unit. Otherwise, its a removal and bench job.

Denso alternators are great units and rarely fail. But if they do, as you pass 150K, here's a source.

Hope this helps someone.

Panthera

 

Have read that the cost to get this done at a shop is outrageous for the labour alone.

 

I had 3 replacements fail almost immediately. The Denso was the only good option. What I noticed was that my alternators were failing after some spirited driving which required me to downshift which in turn causes high revs. Those bearings dont like sudden speed changes.

 

True -- only makes sense DIY. I'd go with a Denso-rebuilt unit if I needed to. Certainly not a Jag sand-in-the-vaseline one.

 

You mean remove and replace the alternator, or the process of the rebuild itself?

The actual price at my local shop was $80 for rebuilding my 00 XKR Alternator. No issues with my 07, but I've had quite a few alternators and starters rebuilt by the local shop over the years since he's only making like $20-30 profit tops on each rebuild he's done, and he warrantees it for a year, its on the way to my dad's work so he just drops off and picks up to/from work.

 

remove and replace,

 

There's a specialist Alternator Rebuild place near me. He's done a tiny bit of work for me, but never an alternator. Nice guy, and he seems capable. He's been in the same building for 30 years now and it still has constant business. Course it's ALL electrical work, not just alternators.

 

I did a bit of research on alternators. Bushings do go and are cheap, but the bearings hardly ever go. If you have low mileage rebuilding it would not be a terrible way to go.

 

if you manually shift or use sport mode the hard revs upon downshifts will definitely wear out the bearings. Ive seen it several times on XKs that are driven competitively. If you pussyfoot the car, then you have nothing to worry about.

 

Thanks for posting this @panthera999 . These jobs are fun.

 

alternator rebuild business has always been a race to the bottom. half the chinese regulators on the market can’t even get the L terminal to work 😂😂😂