Just a heads up for you supercharged Jag owners: Do not replace your OE spring type torsional SC drive coupler with a solid one. Unless, of course, you want your engine to sound like a coffee can full of rocks at idle
Yeah - you guessed it - I just finished making this mistake. While doing my valley hoses, I pulled the SC snout and found the original spring coupler was worn (and beginning to crack, at 130K miles). Rather than installing a new Eaton M112 spring coupler (about $75), I listened to a "SC Guru" and ordered his Eaton solid coupler (about $20) instead. Big error. The spring coupler dampens torsonal oscillations which otherwise create a really noisy SC gear rattle at idle speeds.
So. pulling the XJR supercharger is a genuine pain (mostly because of incredibly tight access to the throttle body and EGR valve). But, I'll probably do it again, just to get rid of the noise...
(Posting this with the hope of saving someone else the trouble)

 

hisport,
you are correct!! I made that mistake last year, and have suffered the rattle every since. However, I have are spare supercharger, that I rebuilt a few months ago and it has the original type coupler. I plan to swap them out soon.

 

Thanks, Joe!
- On your rebuild, did you replace the center plate bearings? Any issues with resyncing the rotors?
- (My SC seemed fine inside; v clean. The rotor/housing teflon? coating was intact, so I just changed oil and put in the idiot solid coupling. The "rebuild" kits" I looked at mostly seemed to include just snout bearings and rear needle bearings, plus oil and solid coupling.
My plan at this point is to simply swap in an OE spring coupling, but I'm very open to suggestions)

 

hispot,
mine like yours was ok and rotor coating was intact. However, I did replace the nose cone and rear needle bearings. The spring was broken in on the original coupler, that's why I did the rebuild kit

 

Hisport,

my F-type V6 was making that « can full of rocks » noise at idle from time to time, and especially when turning it off, so I guess it was the SC coupler, changed it last week for a Solid one, and the noise totally disapear.

And yesterday, after 200 miles since the change, I noticed a very loud « coffee can full of rocks at idle » not noticeable from the inside, but one the hood is open we can hear it and it’s really loud.

I noticed no issue with the SC or bearing so I guess it’s the coupler that’s the cause of that noise, the car works normally, no loss of power, just that awful noise..

 

Hey Rotax,
Thanks for the clip. Yup, that sounds like the dreaded gear rattle...
- Believe your SC V6 F type (wonderful car!) uses the later Eaton TVS 'charger? (Older X350 jags use the Eaton M112)
- I'm casually shopping for a 2010 - 2015 XKR, which also uses the TVS 'charger, and understand that these cars have a
lot of coupler failures (X350's and early X150 XKRs - all 4.2L - not so much)
- I don't believe the gear rattle is actually harmful, just bloody noisy
- Funny; I've made this mistake before. Years ago, had an '85 Porsche 930 (911 Turbo), and replaced the OE rubber center clutch disc with a HD Sachs spring center clutch kit, only to have "can 'o rocks" transmission gear rattle at idle. Sigh...

 

Hi don’t know if it can do any dammage to the supercharger or engine, Don’t want to risk anything I’m gonna change the full nose like Jaguar recommand, and with a spring coupler.. will keep you informed if it’s better !