As I have recently changed the alternator on my 1998 XK8 i wanted to share this painful experience to anybody who is going ahead with this change. First get the JTIS repair instructions 86.10.02

This is what you have to do:

1: The first thing is to remove parts so you can get clearance to the Alternator
– these notes are complementary to the JTIS repair instructions 86.10.02.
And as a note to whoever designed this in Coventry, it’s the worst I’ve
ever seen.

- In addition I have seen comments on that is is possible to remove the
alternator from the bottom of the car. I checked a couple of options and
could not see a way of achieving this.

- First cover the wings/fenders with towels. You will be working over these
for 5-6 hours.
- Remove all the plastic covers from the engine.
- Partially drain the cooling system.
- Remove all hoses on the front of the engine that go to the radiator.
This gives you clearance to remove the cooling fan.

See Pic 1.

- Remove cooling fans
- There are two screws
- If you undo both of these and remove the two connectors from the
bottom of the fans the unit will slide up and out of the engine bay.
Note: The nuts and bolts are nopt captive and will fall in the engine
bay if you do not capture these. In addition access to the
driver side nut is extremely difficulty. To replace this I had to
use my son, who had smaller hands.

See Pic 2 and 3.

- Remove air scoops from underside of car.
- Remove serpentine belt, Just pull the tensioner back with a large
wrench.
- Don't Let the hood fall while you have the wrench still on the
tensioner. It causes a lot of damage to the hood.
- Remove air box
- This should have been simple but the rubber grommet that the
nut is attached to is difficult to hold making is close to impossible
to remove a 16 year old nut. I ended-up cutting the nut off.

See Pic 4.

- **** Open doors, and lower windows (if you don’t do this before
removing the battery the car loses the positions of the doors and
windows in the computer)

- Remove Battery

Finally you have access to the Alternator.

- Replace Alternator

- I purchased a reconditioned unit from Denso. It looked like a brand new
alternator and was <$200.
- Remove connectors from back of alternator.
- I could not remove the connector from the back of the Alternator. After
about 1.5 hrs trying to remove the small connector, circled in red I cut
the wires. (hopefully you can remove this connector on your car and do
not have to do this.)

See Pic 5.

- Remove bolts and nuts from alternator.
- The bush at bottom mount is so tight you can’t even move the unit.
- Have two people use brute force to remove the alternator.

- The Alternator is removed.

See Pic 6.

- Once the Alternator is removed make a special tool to push the bush
back so you can fit the new alternator. Push the Bush Back.

See Pic 7 and 8

- Once the unit is out you can remove you can remove the connector from
alternator and re-wire to the cut wires (hopefully you can remove this
connector on your car and do not have to do this.)
- Re-fit alternator
- Put everything back in reverse.

- Run through coolant re-fill procedure. Fill-run-cool cycles.

I hope this helps, it worked perfectly.

 

Attached is a Pdf version of the post.

 

Nobby,

Sounds like you had a few painful moments with this. Glad you finally got it done.

I did not follow the full procedure on mine. I left the radiator hoses connected and took the alternator out thru the top. However it did take some creative turning. It is also easier to go underneath to disconnect the wiring (mine came off OK) and loosen the bottom bolt.

The only hard part was the bushing you described. It was indeed a PITA to get the alternator out past that bushing. However once out, it was downhill from there. A light tap and the bush slid in enough for the new Denso unit to go in. Reverse the procedure and good to go.

Thanks for the pictures. Always good to have a visual record for the next guy. Wish I had seen those before I fought with that dang bushing.

 

Mike,

For the Multi-Plug on the back of the alternator, I tried everything from above and below it wouldn't budge until I got it on the alternator on the bench and it still acted like it was glued/loctite'ed.

I still don't understand why they designed the bush so tight.

it was so nice when I had finished this, if I was a Jag garage, I would charge double for this one.

 

If you were a Jag dealer, charging double might be a discount.

 

I did that repair once, next time it needs one it will be going to the shop.

 

Well I guess I was lucky when I did my 99xk8 it seemed to along a lot easier.

 

Thanks for the great pics and writeup, Nobby. I've just completed this job after a shipping holdup. Apparently the shipping label fell off. Have to admit I haven't heard that one before.


Not too far out in my experience. Last time I replaced an alternator (and I haven't done very many) it took about 20 minutes. The joys of shoehorning a big motor into a tiny space.

I managed without removing the cooling fans, although I had to take off the mounting for the air box together with the suppression unit to get enough juggling clearance.

One tip: I tried the 'special tool' bush mover I'd read about somewhere else, but I just ended up with a collection of bent washers; hell this bush is tight. But - there is room to get a ball joint splitter on the lug and that worked a treat. Still needed a couple of gentle taps with a hammer, though.

My symptoms were the 'pulsing lights and lots of errors on the dash display' version of events (and code 1793), so I pulled the covers once I'd got the the alternator out. The regulator unit has a connector that looks like a solder tag (see pic) and its pretty fragile. Mine had corroded and literally fell off when I disassembled it.
I was going to try a repair as the car is low mileage and I was pretty sure that would solve the problem. However it's such a bear that I didn't want to do the job over plus I got a good deal on a reman unit. If anyone is keener than me I wouldn't mind betting this is the cause of a few with similar symptoms.

Anyway I've rambled enough. Off topic, but I did get one out of my bucket list yesterday - a long drive in a gorgeous XK150

P.S. It does look as if it will come out from the bottom if the oil filter is removed.

HTH,
Mike

 

Wow! Now I am glad I purchased a used alternator from a junk yard. I went in from the top and bottom. I did remove the serpentine belt, air box and left all else intact. It was straight forward except the mounting bolt that is inserted from the rear, not the front. There is no real need to remove the radiator or hoses (messy). Not a bad job, lots of info here. Thanks for the photos!

 

I'm going to have the lower cross beam out while supporting the engine from above. I'm going to try to change out the alternator then.

 

On my xkr all I did was remove IC pump bracket and air box assymbly. Took me 30 min.Hardest part was the bushing that was welded in place on the bracket. It didnt want to budge and needed a lil heat and love. IS the xk8 that much worse? Kind of looks the same. And it came out from the top

 

No! I did not find it to be difficult at all. When I did mine I did it in the driveway from the top. However, it all depends on the available tools and the work environment.

 

Just replaced alternator on my 1997 XK8 due to irregular voltage causing the lights to fluctuate up and down in brightness. I found the easy way to get the alternator out was from the top, remove air filter box and it's mounting bracket (two 8mm head screws to inner wing). Once disconnected the alternator lifts out easily through the top. I did have to remove the alternator bracket though (4 bolts) to free the seized spacer before I could fit the replacement.

And yes it did fix the fluctuating charging voltage.

 

 

 

XJ: - different beast.

 

I replaced my alternator some years ago and as I recall I needed to remove the oil filter for clearance to get it out, so I did an oil change at the same time. But other than that, I don't recall any issues.

 

Had to change my alternator today due to fluctuating voltage causing flashing lights and numerous faults. Having read all of the horror stories about this job and poor access I prepared for the worst. However, I followed the clear instructions in the Pdf and the job went amazingly smoothly. To help remove the alternator I used a tapered ball joint splitter from below and gently levered the whole assembly without any need for undue force. Secondhand replacement was fitted in no time and all is now running well with a steady charge and no faults. I presume that the fault lies with the voltage regulator as the alternator was still providing a good (too good at times) charge.

 

The sliding rear bush is a common alternator fitment. The front bracket is solid but if the rear were the same it would crack the bracket so they fit a sliding bush to compensate for production tolerances and relieve strain on the rear bracket.

 

There is a tab on the side of the plug that faces the outer perimeter of the alternator. I was able to remove it from below, after removing the nuts/bolts that hold the alternator in place, and rotating it to get a better view. I used tongue-and-groove V-joint pliers to firmly grasp two sides of the plug (including the side with the tab), then twisted the side with the tab away from the socket. Now if I could only figure out how to get the $#!$# alternator out of the engine bay!