The squeal was occurring at every start-up last two weeks. Very un-Jaguar like! The alternator would not get charge voltage until the "catch" of the bonding a few seconds after start. I had some concerns about removing the balancer on the V12, but all went well.

The giant 1-5/16" bolt came loose using the starter bump method... at the fourth try! The pulley came off easily with a standard screw-in puller (not a jaw puller). The radiator did not need to be removed. The bonding layer was visibly cracked after 23 years and 96000 miles. No surprise there.

The balancer is on its way to Dale Manufacturing in Oregon. Excellent reputation, good price, lifetime warranty, two day service. I learned that his operation closes down four months out of the year, including June. So I got lucky with the timing! Updates to follow.

 

Something else to add to my list of things to check. Thanks

 

I have one to do also. Let us know how it turned out.

 

All went well with the rebuild. Just finished all the work. The only real pig was to find a way to hold the damper still while tightening the bolt. I made do with a pulley holding tool that didn't really hold all that well (it is supposed to grab and hold at the edge of the pulley). I'm sure the torque is not up to spec of 180-220 N-m! I may have to revisit that bolt.

The service manual says to "fit a suitable wedge to the drive plate" (at the transmission) or use a "pulley lock service tool" for immobilizing the damper. Who knows about the tool, but maybe there is access to the drive plate from underneath. I didn't check for that. Any advice?

Also I learned after the fact, that the pulley is a two-piece unit and only the innermost section (for the alternator belt) has to be rebuilt. I unnecessarily sent the entire thing to Dale's. Oh well. Glad it was flat-rate shipping!

In total it was a two week turnaround for the damper job, plus some more time for work on the cooling system, replacing some hoses and such. Happy to be finished for now and back to cruising in style.

 

Yeah, I've got a startup squeal right now that is yet to be determined loose belt or damper. I'm hoping it's the belt, but we'll see.

Is the test similar to the AJ16 engine damper, which is to paint a white stripe across all the pulleys to see if it remains aligned? Or is there another method to determine if a V12 damper is slipping while still on the car?

What's the cost for the V12 damper rebuild?

.

 

You can certainly paint the stripe across the pulleys, although it is not nearly as easy to reach or to see as on the AJ16. I didn't bother with marking it, I could tell what was happening from the noise and how it coincided with a temporary lack of charging. I had already checked the belt tension and tightened it a bit, but the squeal got worse and became more frequent, occurring on both cold and hot startup.

Dale's is a lot cheaper than Damper Doctor. Dale's starts at $130 (which was my cost) plus shipping both ways, in a medium Priority Mail flat rate box, $13 each way. I insured mine for $500, even though that wouldn't help if it got lost!

Dale's website: new home page H.B.

What's with this new font in the reply box?? It is too small and too light. Now I have to zoom my screen. Ridiculous that even though phone, computer and TV screens keep getting bigger, text keeps getting smaller. I can't even see the period! Stupid!!!

 

Do you know if the specs (bolt size, torque) for the 6.0 V12 is same for a 1994 XJ40/81 V12 as the 6.0 V12 in the X305?

And do you know if the "starter bump" removal method works just as well on the V12 XJ40?

I assume the engine is essentially if not exactly the same, so "yes", but just checking.

 

The bolt size is 1&5/16". I recently saw this big socket, 6-point 3/4" drive, at Lowe's for about $20 or so. I was looking for a puller which they didn't have.

The starter bump method should work fine, but only bump the starter for one second. If the bolt doesn't turn first time (and come loose, allowing the engine to turn over), wait a while before trying again. A huge amount of electrical heat will build up in the starter real quick if the bolt won't come loose.

I'm learning that there are quite a few subtle and not-so-subtle differences between these V12s. I'd say the XJ81 V12 is more like the last-gen XJS 6.0 V12.

 

I just finished up having mine rebuilt. I was lucky to find a company local to me so no shipping. I was too afraid to use the starter method. A 24 inch chain wrench, and an old fan belt scrap to protect the pulley, works perfectly for both removal and torquing it back on. I wasn’t able to get my puller to work. It appears the holes are not threaded to attach the puller plate to the front? Maybe there are threads way down in there? Anyways plan B worked fairly well, which was gently prying while hammering with a rubber mallet. Did something similar putting it back on, at least until it was on enough for the screw threads of the big crankshaft bolt to bite. Overall a fairly simple job and way easier than on my XJ8!

 

Is this a job that would be easier to execute with the front subframe out? I ask as when I rebuild ny front end I'm looking for south side of engine things to do that will be easier while there is easier access...

 

I don’t think it would help any from what I can see. Now if you had your oil hoses off to replace and also removed the lower crossover pipe, that might help from below. It was fairly easy to remove from above though. When I removed it I already had the water pump out getting rebuilt and also had the AC compressor removed along with the power steering pump and all the radiator hoses. I left the radiator in, just put a thin board in front of it to protect. With everything in place it would be hard to whack with the rubber mallet. I’m still trying to figure out why my puller didn’t work. Are there threads deep inside the outer holes? Mine wasn’t threaded at least the first inch down

 

G'day John,

When I R&Rd my harmonic damper I found that although there were holes around the perimeter of the pulley none of them were threaded! So I ended up using a suitable tap and threaded a couple of holes so that I could use a puller.

Cheers,
Jeff.

 

Ahh so that was what I was suppose to do. Thanks for the info Jeff. I’ve been to your part of the world a few times. The Gold Coast twice with the family and up to Tambourine Mountain. So needless to say, I’m jealous you live there

 

G'day John,

When I went to remove my damper I tried every close sized bolt I had lying around and even bought a few extras to try and find one that would screw into the holes but no luck. Never in a million years would I have thought that the holes were not threaded so I thought the only option would be to tap the holes with a known thread so as to use a puller to get the pulley off. It wasn't until I took the damper to an engineering shop to source correct bolts when the attendant said "Mate these holes aren't threaded" that I found out they were just holes.

You're right this part of Australia is pretty good. Twin Waters, where I live is around 70 miles north of Brisbane on the Sunshine Coast and today, in the middle of winter, it is fine and clear with a temp of 22 deg C/ 71 deg F and a light breeze. Rough.

Very little covid19 around here, around a 1000 cases in the whole state of just over 5 million with only a handful of deaths. We now have unrestricted travel within the state now so my wife and I are off on a road trip in a couple of weeks to explore some of the sights.

Cheers,
Jeff.

C

 

Thanks!

 

And for me, a generic puller set made a quick job of pulling the damper off - the set came with bolts that threaded perfectly into the holes on the damper! Go figure. I can't remember which bolts I used, but it worked as I expected.

My damper has a hex adapter on the front of it that protrudes to allow the engine to be turned with a wrench. It is held onto the front of the damper by two bolts. Maybe those were the holes I used for the puller. Have you guys got the hex adapter on the front? I think it is a 7/8" hex bolt that is basically in front of the large damper bolt.

If not, I may have an earlier version of the damper, my car being a very early build. ?

 

G’day Richard,

I think your damper is a carry over from the later XJS cars. My damper is one piece, not a multi piece bolted together, and definitely doesn’t have the hex extension on the front.

Cheers,
Jeff.