I just replaced my Alternator with a 100 amp Landover defender Alternator based on this recent great thread on the other forum by gregma and Aristides and Robert King. The alternator mounts line up and Greg found a belt pulley that aligns perfectly. Very easy.

Jag-lovers Lucas alternator thread

I found a couple time savers from what they recommended so I'll post those here now and over there if I can ever get help getting access to my account. I am not finding a way to get a hold of any one to ask about it.

Two differences in the way I did it. All my belts were fairly new so I did not want to change the Alternator belt but use the original. The pulley is slightly larger so they changed the belt. My guess was that there was enough play in the adjustment to accommodate the difference between a 70 and 74mm pulley. I was right.

The second thing I did differently was take the alternator out the bottom. If you Jack up the front, pull the wheels and remove the sway bar links completely and swing the sway bar down, and disconnect the oil cooler line from the bottom of the engine the alternator drops out easily. My oil cooler line was leaking so I was going disconnect it anyway and change the o ring.

Because I used the original belt and the tension bolt is mounted out the width of 3 or 4 washers to align with the new alternator, I ran into one issue where I just stared at the Alternator for about 45 minutes. The tensioning bolt was now running into the oil cooler line with it adjusted in so far. It is nearly impossible to move the oil line and highly undesirable to mess with it.




But the Lord giveth wisdom. After staring at it in frustration for a long time and saying a little prayer, it occurred to me to flip the tensioning bolt around so that the free end points towards the fender. It worked great.



Note the 4 washers on the engine mounting bolt to get it to align.

Also because the electrical connections are on the bottom, I had to remove the bolt holding the excitation wire on the fender well to pull it down to the D connection. It is still held down by a riveted bracket.

Started it up and it is charging well.

I also found Dorman 31019 sway bar end link bushings that fit fairly well. I found these in stock at the auto parts store.

 

Goodo.

There is always many ways to skin a cat.

I used the Bosch 110 from XJ40 cars back in the day. There wre MANY of them in the wreckers back then, not so today, they have a new following and being cared for.

Fitted 100% spot on, and the OE belt was retained.

 

Update, its running well. A lot of electrical gremlins are gone now, such as dancing speedo, radio won't turn on, etc.

I'm getting 14.5 volts at idle and 14 volts at the battery with bright lights, high blower, radio and high wipers all on.

I'm having s good drive in spite of all the little things to fix.

 

A little update... When the car is in gear and stopped, the engine RPMs are around 550. With a light electical load, the system voltage is 13.5 volts. When I turn the fan and wipers on high and the high beams on, the system voltage at the battery is 12 volts. If I take it out of gear or accelerate, or any other reason it crosses 800 RPM, the voltage jumps up to 13.5 volts. So the only time it will drop to 12 volts under heavy electrical load would be at a stop sign, stop light or traffic jam when it's really raining and I need to have defroster on. I'm not sure I care to do much about this. I'll probably wait to see how if it ever becomes an issue. I think if I convert to electric cooling fans I'll need to change the pulley to a 67mm pulley.

 

What year is your car? From VIN 185820 onwards they come with a Bosch 115A alternator and the 6.0 cars have a 120A alternator.

 

550 is low... if you idle it up just a little bit, even to 700 - 750 I suspect that voltage will level out and stay at a good level. All them things on will stress any electrical system, I would say the next and right thing to do is clean the heck out of any and every electrical connection you come across, front to back. It actually sounds painful, just just make a day of it. It pays off for sure...

 

550 is in gear with my foot on the brake. 900 in park, so a little high actually. It charges fine above 700 RPM.
I'm wondering if the lower RPM has to do with the 700R4 and 1800 stall torque converter
I checked the belt and it didn’t seem loose but was just a bit. I tightened it and I now get 12.5 volts at 550RPM in gear and all the electrical load on. I'm calling that good.