Replacement of Fan Clutch Jaguar XJ6 Early Series 2

Hello Jag-lovers!

New member to the forum, long time reader and proud owner of a 1974 Jaguar XJ6 Series 2 SWB. I am reaching out to the community since I know that there is a lot of experience and knowledge here. I have read through the forum but I am still not confident that I have the answers I feel I need regarding this topic.

My fan clutch (viscous coupling) is broken. I come to this conclusion since I am able to flick to fan without any resistance and it will spin 10-20 times. My car also runs a bit hot. From the parts manual and what is used in my car I identify the currently installed fan clutch as #C.28018. Unfortunately this item does not seem to be available any more. After searching online I understand that the replacement item is #NBC2215AA but I would like to get this confirmed before I order a replacement.


  1. Do you believe NBC2215AA is the correct replacement part?
  2. Has anyone experience of replacing the fan clutch on an early series 2?
  3. I understand that NBC2215AA is “taller” than C.28018 and that it will come closer to the radiator. But will it be too close to the radiation? Any concerns?
  4. Do you know if NBC2215AA is a thermal clutch or not? I believe the original clutch is not thermal.
  5. Does the radiator need to be removed to fit NBC2215AA or can it be done by removing the top of the fan cowl?

Looking forward to hearing your answers.

Thank you and best regards,


Welcome Marc,

you seem not too far away, so I dare to suggest a German supplier who seems to have both on stock, NAYY. I take it you checked SNG already.

Good luck


75 XJ6L 4.2 auto (UK spec)

Hello Marc, welcome to our group. We have dealt with the viscous coupling problem recently and the archive has the history. I have a Series 1 XJ6 the below link will bring up the thread - many of us contributed so it is a little long! Paul.

Thank you Jochen!

Correct, I am not too far away.

I did also find the site you linked to and indeed the description is correct for my car, however it seems that the item in the link, #336851, is is also recommended for series 3 and I do not believe that originally the same clutch was used for early S2s and S3s. This kind of makes me believe that Limora, like SNG and Angloparts will supply NBC2215AA or a part not identical with the original part. Of course if Limora does recommend the part for an early S2s it is an indication that it is the correct replacement part. Also they have a “special price” on the part :slight_smile:


13mm will fit but is slightly too large. Beware of rounding off the bolts, not the end of the world but not nice.

The small bimetal spring coil on the front makes this thermal. Nice addition if you ask me, not that you would need it too often if at all.
I do not know whether it fits dimensionally though. Assuming it does…

The radiator must not be removed, total waste of time. Removing the cowl top alone should do. If you are extra careful, get a piece of cardboard behind the radiator for protection; the fan has to come out with the clutch, so remove the four water pump bolts before removing the fan bolts for extra room.
Good luck.

Thank you Paul! I read this post a few days ago and it provided a lot of good information. The replacement alternatives in the post are potential candidates but they seem hard to get a hold of in Europe.


Thank you David for the valuable advice!

Where did you get your replacement part? Was it an NBC2215AA?

Do you mean that it is possible to remove the clutch and the fan as one piece and than swap the clutch on the work bench?


For my Series 3, I had a spare clutch when I bought it. It looks identical, though. On the new to me Series 1 one nut didn’t want to come off, so I removed the whole unit even including the water pump without dismantling the shroud at all (I didn‘t realize that the top comes off!).

So the idea is that you remove the four nuts at the flange, that hold the clutch to the water pump. If that doesn’t do it, loosen the fan so you have more room, otherwise, do this on the bench where it is easier. The fan slides off to the ‚rear‘. I‘m sorry I can’t help you with the correct clutch type. What I can do is look for the S3 clutch if I have not thrown it out and put it next to a ruler and the S1 clutch.

I think i threw it out. Sorry. Maybe a centimeter or two, nothing serious. Will look at the installed one tomorrow.

Thank you David! Seems like a manageable job.

I think I will order the part from the site Jochen linked to unless anyone knows of any reason I should not.

I will keep you updated on the progress. In the meantime, thank you all.


It might take a few days… until it arrives, based on my only experience, but the price seems alright, so go ahead! Shipping from Britain is only worth it in larger batches mostly.

It is not too hard if you wear gloves and the bolts are not too bad. Had to remove my failed one in a parking lot, so… good luck! Quick job after the first time. Don’t be surprised if you have to loosen all before you have clearance to get them off, that is how it is with the S3 clutch.


An update on the fan clutch issue.

I managed to find a used but functioning original S2 fan clutch and the difference is obvious. There is now a minor storm in the engine bay so the fan and clutch are definitely moving a lot more air.

I was not able to loosen the nuts holding the fan clutch to the water pump (I probably need to workout more :sweat_smile:) and was eventually forced to have a mechanic do the job. Took him two hours so it was rather cheap.

Thank you for your support and good advice.


Cool Marc! A full line of success stories.

Two cars of mine use viscous couplings as fan clutches. The Jaguar SII is quiet, but does its job, the Spitfire’s clutch that I replaced two decades ago is much louder than the original used to be, in fact produces a howling sound when revving up, but produces quite some airflow. The specs of viscous couplings seem a bit hard to check it seems.

Good luck


75 XJ6L 4.2 auto (UK spec)