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Last year I had charging issues. I replaced the alternator and for it a bit it seemed to be fixed. It definitly got rid of the loud squealing on startup. However, there were times when I still noticed it wouldn't charge for a few seconds. Now this year charging is very sporadic and only happens after being driven and warmed up. I also notice there is a subtle chirping and until that stops, it's not charging. My assumption is my damper is shot. Moss has an aftermarket (on back order) that is fairly priced. Does anyone have experience with the aftermarket ones? Most threads reference having the current one rebuilt, but the cost and time still makes the aftermarket one more reasonable. There are also a few used ones available that state they have been tested, but I'm not sure if that is a good path to follow. Last question, from what I see the dampers are universal for all years of the XJS, it's just the pulley that changes, is that correct? Moss said they would most likely ship the first week in June, which isn't horrible or I could try a used tested damper. I'm open to opinions. The job itself doesn't seem too bad. I saw some tips in other threads for removal and replacement. Thanks,
Last year I had charging issues. I replaced the alternator and for it a bit it seemed to be fixed. It definitly got rid of the loud squealing on startup. However, there were times when I still noticed it wouldn't charge for a few seconds. Now this year charging is very sporadic and only happens after being driven and warmed up. I also notice there is a subtle chirping and until that stops, it's not charging. My assumption is my damper is shot. Moss has an aftermarket (on back order) that is fairly priced. Does anyone have experience with the aftermarket ones? Most threads reference having the current one rebuilt, but the cost and time still makes the aftermarket one more reasonable. There are also a few used ones available that state they have been tested, but I'm not sure if that is a good path to follow. Last question, from what I see the dampers are universal for all years of the XJS, it's just the pulley that changes, is that correct? Moss said they would most likely ship the first week in June, which isn't horrible or I could try a used tested damper. I'm open to opinions. The job itself doesn't seem too bad. I saw some tips in other threads for removal and replacement. Thanks,
They are not universal. If your car is 1990 it will require marelli suitable damper. The alternator drive pulley changed at some point in the cars production also, alternator pulley is integral with damper, not part of the bolt on pulley cluster.
Really is a very DIYable job to rebuild yours though.
I do have a 1990 and that is unfortunate. The "fitment" for the aftermarket part EAC9693, doesn't designate years, so I assumed it was for all v12 XJS. It also does not have an integral pulley, so I'm assuming that's off the table. However, I am interested in doing my own rebuild. I'll have to do a search on that, but if you have any info I'll take it. Thanks for the reply
I went and looked again at some old threads and the Moss aftermarket part EAC9693. I think the one they sell is actually for the Marelli era cars. It does have the alternator pully integrated ( I believe) and then the additional pulleys are then reused. If anyone can confirm this I'd appreciate it. Thanks
[QUOTE=stone4140;2909924]I went and looked again at some old threads and the Moss aftermarket part EAC9693. I think the one they sell is actually for the Marelli era cars. It does have the alternator pully integrated ( I believe) and then the additional pulleys are then reused. If anyone can confirm this I'd appreciate it. Thanks
Yes, the Marelli damper connects directly to the crank and then the other accessory pulleys bolt to it.
I changed mine for a Marelli crank pulley. I was going to go to Moss for it but found a better deal on amazon from a seller in the states. Exactly the same item. Easy swap no more squeezing fan belts with my new 120amp alternator.
I changed mine for a Marelli crank pulley. I was going to go to Moss for it but found a better deal on amazon from a seller in the states. Exactly the same item. Easy swap no more squeezing fan belts with my new 120amp alternator.
Ya unfortunately it seems like everywhere including Amazon is sold out. Even checked some UK sites and nothing. I'll have to place a backorder with Moss. Thanks everyone
Check the belt first. My car had a similar squeal and tensioning the belt to the correct value solved it. A belt tension gauge is cheap (look for a Gates krickit). Note that there are different gauges for V belts and multirib belts, you have to use the appropriate gauge for each type of belt.
If the belt is old it can be worn as well, that would also cause slip.
I would first put some paint marks across the edges of the damper and pulley. Run the car for a while and then recheck. If the marks are still in a line, everything is fine. If they have moved, then you have a slipping outer damper ring
Check the belt first. My car had a similar squeal and tensioning the belt to the correct value solved it. A belt tension gauge is cheap (look for a Gates krickit). Note that there are different gauges for V belts and multirib belts, you have to use the appropriate gauge for each type of belt.
If the belt is old it can be worn as well, that would also cause slip.
I would first put some paint marks across the edges of the damper and pulley. Run the car for a while and then recheck. If the marks are still in a line, everything is fine. If they have moved, then you have a slipping outer damper ring
I will do that that paint test later today. I've been meaning to and keep forgetting when I'm actually home. I replaced the belt last summer, so it should be good, but the tension gauge is also something I've been wanting to buy.
So, what I did when I had this issue which I assume is the same (the rubber insert between inner drive part and the actual pulley has separated), was to drill 3 bolt hole at equal spacing marked by the 3 prong Marrelli trigger plate and bolted it together so that the bolts partially were in both sections.
1. The parts have to be marked/drilled done at TDC to keep the ignition timing correct. Nbr 1 cylinder at mechanical TDC on compression stroke and pulley lined up on timing plate TDC.
2. Yes it does lose the "damping" function, BUT I never had an issue with it afterwords, so I think it was another example of Jaguar over-engineering a part that did not need to be done.
3. Cost was 3 1/4 bolts!!
This "temporary" fix lasted for the remaining life of the car 50K plus miles later with zero further issues.
I do have a 1990 and that is unfortunate. The "fitment" for the aftermarket part EAC9693, doesn't designate years, so I assumed it was for all v12 XJS. It also does not have an integral pulley, so I'm assuming that's off the table. However, I am interested in doing my own rebuild. I'll have to do a search on that, but if you have any info I'll take it. Thanks for the reply
Link to previous thread (go to post #7), pretty simple job with very basic disk jig, 60A flexible heat cured polyurethane. I did this repair about 7 years ago, still trouble free. https://www.jaguarforums.com/forum/x...ebuild-198145/
Check the belt first. My car had a similar squeal and tensioning the belt to the correct value solved it. A belt tension gauge is cheap (look for a Gates krickit). Note that there are different gauges for V belts and multirib belts, you have to use the appropriate gauge for each type of belt.
If the belt is old it can be worn as well, that would also cause slip.
I would first put some paint marks across the edges of the damper and pulley. Run the car for a while and then recheck. If the marks are still in a line, everything is fine. If they have moved, then you have a slipping outer damper ring
definetly the damper, used a yellow paint marker and the marks separated. Still on the hunt for a replacement. I see the threads with rebuilding, but I’m not sure I’m up for that yet. Will keep reviewing them though
I was looking fairly recently, and I don't believe there are any new dampers available in the market. I think rebuilding what you have is your only option.
I found this company after spending way too much time looking for one. 3-4 week turn around to rebuild which isn't bad, also has a great video on its function. Might be helpful for others when they encounter this issue.
Just want to put a plug in for that Jaguarpreserve.com. They actually shipped out a rebuilt damper the same day they received my core. Mine was totally shot, was able to spin it by hand. Thanks for all the tips as well, was not a horrible job at all. I scrapped the entire internet and I believe it’s the only place that is doing it currently.
Sorry it's been a little slow in coming but like everyone I've been busy with too many things that get in the way. Here is an update on the damper rebuild. Finally got the two pieces apart and put them in the mold. Ended up going with a different urethane than I originally planned on but it's finally done.
Here are the results: Here's the front. Here is the back side.
The challenge with the 3M Windo-Weld is packing it down into the center portion as the space is not large enough to get the nozzle in between the center hub and the alternator drive ring. But with persistence it can be done. Working time is 10-20 minutes with the urethane. I chose this product as it has a higher shore hardness that what I was going to use but not as hard as poly bushings. Here's the goods
Did the front side first and let it set over night and then pulled it from the mold to pack the back side.
May get it installed tomorrow
Crankshaft Damper Replacement
