So I tore the SC apart recently. I cleaned the inside of the housing and the rotor surfaces lightly with a scotchbrite pad. After 100K miles they were pretty caked with oily residue which I understand is normal. At the same time I applied some of the Eaton recommended high temp grease to the needle bearings. I replaced the oil with what Eaton recommends filling the oil reservoir until it reached the plug hole. I machined the snout and replaced the OEM pulley with the smaller 2.5lb pulley from Powerhouse. I also replaced the drive coupler with a oil filled plastic one. All seemed fine after all of this was completed when I was spinning it lightly on the bench. However, now that the SC is back on the engine and running it seems to be making an odd sound. It is hard to describe but it almost sounds like the rotors are rubbing on something or themselves. I really do not want to have to take the SC back off but the noise concerns me. Any insight is much appreciated!

 

Hopefully the stuff you rubbed off wasn't the teflon coating, though I'm pretty sure that was only on the later generation eaton's on the 4.2 engines. Was there any play in the rotors when everything was back together? Maybe the coupler has something to do with it, I've read some people having weird noise issues due to using different type couplers. Can't remember which style ended up solving the issues.

FWIW the blower on my XJR makes the same noise kind of, but I haven't pulled it apart or inspected yet, I've got a newer blower which I'll overhaul and install in its place sometime.

 

don't stress . that i very common after a solid coupler install . you have a little backlash between your gears teeth . amplified with the solid coupler .a good bit louder at high idle or on over run , and when loaded in gear . but otherwise only a little louder than when stock.
i'm in the same boat with mine ,
i replaced the rear needle bearings , replaced the snout bearings and seal, swapped in the solid coupler . chucked it all back on and it sounded average .
works great still 5000 km's later. welcome to old car mods.
all good fun. this is repeated all over the buick and the CTSV forums too .
ps nilanium is correct there is no teflon on the gen4 eaton only the later gen5 4.2 ones, so thats not to be worried about here.

have a look here i posted this when i stumbled across this issue a wile back

https://www.jaguarforums.com/forum/s...ads-up-176686/

 

Sorry that it took me so long to reply to this thread. I was in Ireland for a week. What a relief it is to hear that this sound is common after replacing the coupler with a solid one. Thank you so much for the reply Datsports.

 

Credit to nilanium also who also knew of the issue and stated it , but I had first hand experience,
Including the holy crap moment and the subsequent searching for the reason !
Thankfully the extra chatter is harmless in the short term and hopefully the long term also , seems to be however ! I'm clocking up km's all the time , and the sound is the same as the first time I've heard it . And that all that maters, if you hear it get worse at any point , then do somthing about it , I hardly ever notice it anymore.
Just one more wee quirk , So go beat on that supercharger.