XJR Supercharger coupler/isolator

[mickrick]

A bit of a rattle on start up that I thought was timing chains, but did seem to emanate from the supercharger snout.
I'm doing the timing chains and tensioners anyway, and I'm also going to overhaul the charger, fit new bearings and a solid isolator.
But just wondered if this was considered normal? I feel no play in the bearing whatsoever.

https://youtu.be/4-G4vJ9M_ZY

Edited by mickrick on Saturday 18th April 19:00

Edited by mickrick on Saturday 18th April 19:01

[lexusboy]

You can get a low level repair kit for these super chargers from a dealership.

Comes with new complete snout and bolts.

They’re a bit of a pig to get off the charger as they are RTV’d onto the body

[mickrick]

Hi thanks for your reply.
And thanks for the heads up on the RTV! Bearings I’ll just order from our supplier at work.
There’s a company on eBay Powerhouse-UK selling solid coupler/isolators, do you have any intel on them?
I’m also upgrading the charge air cooling system a bit, bigger capacity cooler, new Bosch electric pump, and I’m looking at removing it from the engine cooling system by fitting a swirl pot/ header tank.
I live in Mallorca, so the ambient temperature can get up to 40+ degrees C in the summer.

[lexusboy]

mickrick said:

Hi thanks for your reply.
And thanks for the heads up on the RTV! Bearings I’ll just order from our supplier at work.
There’s a company on eBay Powerhouse-UK selling solid coupler/isolators, do you have any intel on them?
I’m also upgrading the charge air cooling system a bit, bigger capacity cooler, new Bosch electric pump, and I’m looking at removing it from the engine cooling system by fitting a swirl pot/ header tank.
I live in Mallorca, so the ambient temperature can get up to 40+ degrees C in the summer.

We only use the genuine parts from dealership so can’t comment on after market parts.

Also it’s not actually the bearing at fault; this is a direct quote from the technical bulletin relating to free play in the charger pulley

CAUSE:

The torsional isolator and or the torsional isolator spring support shaft are wearing, causing excessive backlash in the supercharger drive.

Hence why you change the snout rather than just some bearings

[P700DEE]

Powerhouse have been doing Supercharger work for Jags for some years. I've not heard of any problems.

[mickrick]

Thanks again for the replies. I'll see if I can do a bit more over the bank holiday weekend, and I'll post an update on what I find.
First job though is to get my scaffold poles out to get that crankshaft damper/pully off

[lexusboy]

They changed the thread direction on the bolt but I can’t remember when so just be careful you’re not tightening rather than undoing.

[mickrick]

lexusboy said:

They changed the thread direction on the bolt but I can’t remember when so just be careful you’re not tightening rather than undoing.

First time I've heard that. Nothing in the workshop manual about it, even when they mention cleaning out the threads in the crank with an M16 tap?

[Piersman2]

Check out Jagforums website.

I did a whole thread with detailed pictures on there on the coupler and what I did when I changed mine out.

I've done the same job on my previous XKR 4.0 and my current 5.0.

Basically the coupler wears and then starts to get a bit loose and the spring in the centre starts to bang against the driveshaft, hence the noise at tickover as the loose coupler flaps around a bit.

The aftermarket couplers are solid rubber so can't do this. I used a kit from powerhouse on the 4.0 to also upgrade the pulley at the same time. All good.

On the 5.0 I have now, I used the Jaguar kit (about £400 IIRC) which includes a standard snout and an original coupler with the spring.

Straight forward enough jobs to do once you get stuck in, the worst of it for me was getting all the bits back together on the 4.0 engine as ideally I needed 3 hands the size of a child to try and hold everything in place as I refitted the S/C body back the inlet elbow. Lots of swearing, shouting and almost tears of frustration at that point!

ETA: On the 4.0 wiht the Eaton S/C I intially tried to change out the end bearings. That didn't help. Then I changed the rear needle bearings, that didn't help. Eventually I just coughed and bought a second hand S/C from a 4.2 and fitted that. The problem with these S/Cs is you can't change the middle bearings. Well you probably physically can, but the relationship between the two interlocking vanes is incredibly tight and you'd most likely end up mashing your S/C. Just pray it's the coupler/snout bearing and swap them out.

Edited by Piersman2 on Friday 1st May 08:07

[mickrick]

Hi thanks for your post. I'm 99% sure it's the coupling, there's zero play in the snout bearings, but I'll swap them out along with the seal and retainer, and the needle bearings, as a matter of course. Plus I want to bead blast everything to freshen up the look of the motor. Bearings are relatively cheap, and we have a good supplier at work. same with the seal, I work for a hydraulics company
I also have a 30 ton press at home.
You say you swapped the pulley, I'm in two minds about that, as I mentioned, I'm going to modify the charge air cooling system a bit (I've just ordered the header tank/swirl pot). Which pulley did you fit? and did it make a noticable difference If I do that it would be a good time to turn the snout down if need be.
I just need to weigh up the pro's and cons. Faster charger means accelerated wear, higher charge air temps etc.... Also accelerated belt wear over the smaller pulley, and there's also the option of the bigger crank pulley...

Edited by mickrick on Friday 1st May 09:45

[lexusboy]

mickrick said:

lexusboy said:

They changed the thread direction on the bolt but I can’t remember when so just be careful you’re not tightening rather than undoing.

First time I've heard that. Nothing in the workshop manual about it, even when they mention cleaning out the threads in the crank with an M16 tap?

[mickrick]

Ah, sorry, I should have stated mine's a 1998 X308

[Piersman2]

mickrick said:

Hi thanks for your post. I'm 99% sure it's the coupling, there's zero play in the snout bearings, but I'll swap them out along with the seal and retainer, and the needle bearings, as a matter of course. Plus I want to bead blast everything to freshen up the look of the motor. Bearings are relatively cheap, and we have a good supplier at work. same with the seal, I work for a hydraulics company
I also have a 30 ton press at home.
You say you swapped the pulley, I'm in two minds about that, as I mentioned, I'm going to modify the charge air cooling system a bit (I've just ordered the header tank/swirl pot). Which pulley did you fit? and did it make a noticable difference If I do that it would be a good time to turn the snout down if need be.
I just need to weigh up the pro's and cons. Faster charger means accelerated wear, higher charge air temps etc.... Also accelerated belt wear over the smaller pulley, and there's also the option of the bigger crank pulley...

Edited by mickrick on Friday 1st May 09:45

If you're going the route of upgrading performance, then I'd recommend the pulley upgrade. It reduces the circumference of the upper pulley by a small amount and theoretically is supposed to give 10% increase in power. However, it didn't turn my old 4.0 into a fire breather but did give it just a little more mid range response. Your point about improving the heat dissapation in the S/C to get cooler inlet air is probably a fair one, the under bonnet on the XKRs gets really, really hot so I can imagine keeping the air out of the S/C as cool as possible can only be advantageous whether the XKR or XJR.

When I did the 4.0 XK I bought the pulley upgrade snout and coupler from Powerhouse , they were good and the snout was spot on with the pulley already fitted, I sent my old snout back exchange to them to recondition although in reality there was nothing wrong with it other than someone having painted it red previously.

You'll know as soon as you take the belt off if it's the coupler, there is some play in the pulley , but if the couplers gone you'll have about 20 degress of free movement in the pulley, there is a litle as standard , but not that much!

I did consider the crank pulley but it's just so much hassle to get into to it and pull /press it. The upper is far easier especially if you're stripping the S/C anyways. You could do both, but then you'd most likely need a remap to make the most of it, the upper pulley can just be done with no need to re-map.

here's the link to the thread when I did the 5.0, it includes some detail picures of the coupler and how it wears. There's a couple of other threads containing info on the 4.0/4.2 litre S/C fix as well with some hints and tips from a few folk.

https://www.jaguarforums.com/forum/xk-xkr-x150-33/...

[lexusboy]

mickrick said:

Ah, sorry, I should have stated mine's a 1998 X308

Ahhhh ok

Not too clued up on them as don’t see many of them

[mickrick]

Well that wasn't too bad. It took me about 3 and a half hours to remove the charger, and completely strip it.
I'd better do the valley hoses while I'm at it. It needs a good clean up under there, I think I'll give it a blast with some engine cleaner and the Karcher.
There was some insulation under the charger, I didn't expect to see that. But it's totally disintegrated, I'm sure there's a better, more modern material I can wrap the charger in to insulate it from the under bonnet heat.

[mickrick]

Here's a few pictures of the charger in bits. The coupling didn't look too bad actually. There's two places on the rotors where the coating has come off, and there looks to have been some contact with the housing. Quite honestly I recon there's some play in the center bearings, but I'm not keen to do anything about it at this moment. Maybe it seems worse as the rotors aren't supported in the needle bearings.
I'll change what bearings I can, the seal obviously (Surprised to see a high pressure seal fitted!) a solid isolator, and I suppose I may as well fit the smaller pulley seeing as it's this far down.
I'll drop the snout into the machine shop we use at work, and get him to turn the snout down for the smaller pulley. I really need to get myself a lathe!
I recon I could change the center bearings, but I'm not going to risk it in case I bugger it up. The problem will be lining the gears up on the shafts.
From what I've read, the 4.2 supercharger will fit my car? If so, I may keep my eyes peeled for one later, then I'll risk having a go at the center bearings on this one. Just to see if it can be done.

[mickrick]

And Boy, does that oil stink! I've washed my hands half a dozen times, and I can still smell it!

[mickrick]

I cleaned the snout up in the blast cabinet, and marked it up for the machine shop tomorrow.
The fellow at Powerhouse UK is very helpful, replied super quick to my enquirers, and was very open with information.
I ended up buying everything from him, as the bearing kit was reasonable, and I also purchased the 10% pulley and new coupler.

[Piersman2]

Ahhh... memories!

The 4.2 litre S/C will definitely fit the 4.0 engine... it's what I ended up doing on my old XKR. IIRC there is a bit of trimming required on the S/C to inlet elbow gasket slightly as the needle bearings on the 4.2 are slightly bigger , it's not much and everything still works fine.

You also might want to check the state of those valley pipes that run under the S/C across the top of the engine. Mine were OK, but they are a known issues mainly because if they do go the only way to swap them out is the remove the S/C. Makes a £20 pipe a VERY expensive fix due to the labour if you have to pay a garage to do it.

It's those centre bearings that screw you over. I did everything you're doing and still ended up with a noisy S/C. The first time I took the S/C off and upgraded the snout & coupler. It still rattled. Then I took it off again and changed out the rear needle bearings. It still rattled. Then I took it off and replaced it with a second hand low mileage 4.2 S/C. Sorted.

As you've said, you can't really touch those centre bearings, they are factory set to very fine tolerances so the blades don't mash into each other. I never did find anyone willing to give it a go aftermarket.

Now then... you've done the easy bit, taking it all off. Let's see how well you get on with putting it all back in again! I was nearly in tears the first time as I was knelt on top of the engine trying to hold an inlet elbow, S/C body and gasket together whilst forcing the S/C body over the pipes below and slide on the rubber pipes for the air bypasses.

When I did mine the sprung clips on the two little rubber air bypass hoses were too tight for me to do all the above in 1 go. I ended up binning the sprung clips and using nice hose clips instead. Oh, and further on , I also learnt to hold the gasket in place with a bit of electrical tape which could then be pulled out before tightening the bolts.

See how you get on!

P.S - Yes the guy at Powerhouse very helpful with me as well, praise where it's due!

Edited by Piersman2 on Monday 4th May 16:15

[mickrick]

It seems to me from what you say, that the XJR is easier, as I had no problem getting to any bolts around the throttle body elbow. The throttle body can off the elbow first, and the four bolts holding the elbow on were a breeze.
But as you say, let's see .
I'd already planned to replace those valley hoses as a matter of course. A 22 year old car will definitely need anything rubber changing.
What's the advantage of the 4.2 charger over the 4.0?, besides probably getting a lower mileage one.