Hi everyone, today when I got home from work I had started up the Jaguar to take it around the block.
As I was about to put it in drive, I heard 3 loud knock sounds. They weren’t consistent and were 1-3 seconds apart but I was able to put my ear to it and hear it was coming from the middle of the engine.
So I immediately took the supercharger belt off and turned it back on and the noise was gone. I took it for a drive aswell to make sure. (Is the XJR really that slow without a SC on it?)

My question is what would I be looking at for replacement? I was going to have powerhouse rebuild it but as of right now, that is not feasible, so I’m looking for more of DIY solution until I can send it to them.
All I can think of replacing is the coupler and oil.

Anthony

 

When you took the SC away, you took away about 80HP.
That does seem it could be the coupler, if it's still the OEM the spring could have broken or separated (known issue). You can rebuild the snout yourself, there's many kits available and install vids, you shouldn't need the rotor bearings, but that depends on what you find. Do a search for Eaton M112 rebuild kit, you'll get many results (like magnum powers), ...to include F-150 Lighting M112 rebuild.
There are plenty of places in the US that rebuild those if that's the way you want to go and they refinish the rotor coating (which can cost). Why pay the shipping over to the UK and back.

 

Eaton has a graph or chart showing required power at RPM.

It takes approx. 60 HP to drive a M112 SuperCharger to 12,000 RPM to gain 80 HP at the engine. (6,000 Engine RPM = 12,000 SC RPM)

In other words, you lose more than 'boost', you also use parasitic drag to drive the SC.

 

You can do this coupler replacement job yourself. Use a thin bead of Loctite anaerobic sealer between the snout and body of the charger. Replace only with a genuine Eaton spring loaded coupler. You can find them on eBay. Don’t forget the supercharger (super smelly) oil (turbine oil). If you like the sound of rocks tumbling around inside your freshly installed charger like I did many years ago, use a solid coupler. Biggest mistake was installing one of those solid couplers…never again.

 

Ok I found a rebuild kit for $100 on eBay and I’ll go ahead and buy those.
Is there a thread I can look at for installing the bearings?

Heres a video so you can hear it.

 

I had knocks/metallic rattle/grinding sounds recently coming from my engine compartment when first starting my XJR that went away after warming up. Thought it was the super charger but turned out to be a pulley going bad. The sound echoed all over the engine compartment and resonated through the engine. Check your pulleys before you tear the SC apart. It's much easier than rebuilding the SC if that's the case. If the pulleys are fine good luck with the rebuild!

 

I used a 10 ton press, caliper micrometer and took pictures for the sake of continuity. Everything turned out well.

 

There are a couple of good vids on YT about rebuilding the M112 snout. They are professional rebuilds and you can tell they do it all day long, but you'll have a good perspective....you should use a press (as pointed out by Addicted who beat me to the post). Heck, a Harbor Freight one should do, but measure clearance for the snout.

This is just for review, I say that because he hammers out/in his bearings...not recommended...but he takes lots of pics. Careful not damage the span retention clip. https://www.theinfamousproject.com/m...arger-rebuild/

The video I wanted to show you won't allow a link to another site, but it's Eaton M90 Supercharger Snout Tear Down and Rebuild by Quality Superchargers.