IRS Rebuild

[colinevans]

Hi Steve, that’s helpful thanks. It was SNG I was looking at but I’ll check the others before I order and go with OEM if poss.
Cheers Colin

[bitsobrits]

Another mod to consider at rebuild time is to update the lower control arm to the later S3 (some S2 also?) spec by shortening the front side of the lower shock mounting tubes by exactly 3/8" which allows a modified bolt for the rear radius arm mount to be inserted from the inside rather than the outside (from behind the hub assembly).

This allows the radius arms to be removed/installed separately from the IRS without having to remove the outer fulcrum shaft to get the hub out of the way. Only the front shock on each side needs moved out of the way on the lower end. The IRS re-install is much simpler without the dangling radius arms, IMHO.

I shortened the tubes with just a cutoff wheel, a hand file, and a dial caliper (to ensure I had an accurate and square cut). You'll need a spacer (3/8" wide by 5/8" ID) to replace the cutoff bit when installing shocks, and very nice stainless spacers are off the shelf from extsw.com. For the bolt I used a high strength ARP bolt as that allowed me to cut down the bolt head/flange while still having a full hex for wrenching as the cut was exactly flush with one side of the hex. (whatever bolt is used, you need to cut the head along the bolt axis with the cut just flush with the main bolt shaft) I also used a bolt that was longer than required, then cut down the threaded end about an inch so no threads are in shear, which might be overkill. Also used a half high nylon locknut tapped into the recess where the original pivot bolt head resided. I've attached a photo which might help make this clear.

[angelw]

Geoff Wrote:

further to your description of using a pizza oven to loosen the grip of red loctite is there a necessity to press out the shaft immediately while it is still hot or does heat permanently destroy the bond allowing you to handle the parts when they are cool?

Hello Geoff,
The Loctite is permanently compromised by the heat, but it does solidify when it cools. Accordingly, it is still easier to disassemble the parts when the assembly is hot. Leather welding gloves, or even leather gardening gloves is all that's required to handle the hot assembly. When a lot of permanent Loctite has been used, its common for a circa 8 ton load to be required to get the parts to initially move. Once the first movement between the parts occur, it gets easier.

Regards,

Bill

[Geoff Allam]

Thank you for that information Bill.

[colinevans]

About to start rebuilding as the diff is due back from Alan shortly. The new bushes I bought from Robey for the radius arms are around 3mm too large in diameter than the cup opening. The old ones look fine but I don't know how long ago they were last done, so looking for advice please - keep what I have, or invest in new radius arms at about £75 each inc standard bushes. I am tempted to buy new as the verniers are telling me that the opening on the old ones are oval, so at some point when bushes do go its going to be a problem.
Cheers, Colin.

[tim wood]

All I can say on this is that I purchased some cheapo bushes which within 1 year failed. The rubber separating from the outer ring.

Same with rack mounts, I’ve learnt my lesson and now will fork out for best quality items. All the usuals sell a range of bushes at varying costs.

Tim

[mgcjag]

Hi Colin....you do realise that the large bush only pushes in(presses out)from one side of the radius are.....the large hole is about 3mm smaller (lip) so the bush dosnt just slide out.....Steve

[colinevans]

Hello Steve. Thanks, I didn’t realise but that makes sense. Just need to cobble up something to hold and push them out square in the press now! Guess I could use the new ones at a push.

[colinevans]

Forget that last comment- new ones obviously won’t push out the old ones due to the lip. I’ll make something up.

[mgcjag]

thought you might find that out.......note when you press in the new ones there are slotted holes in the rubber section...you can have the orientation of these holes either inline with the radius arm or at 90deg....cant remember the standard way...its in the service manual....if you have an old bush you can cut the outer ring squeeze it in a bit so you can use it to press out the old bush.....so keep all your old bit they come in handy whene useing a press......Steve

[colinevans]

Thanks Steve I think from memory the manual shows the slots inline. Haven’t got an old bush so i’ll make something this time.
Appreciate the advice as always!
Colin

[colinevans]

Hi All
Just finished plating the handbrake compensator and I’m now looking at the carrier assembly. I wasn’t planning on doing much here other than a quick clean but the return spring looks a bit rusty, even though the handbrake worked well prior to the strip down. The manual isn’t very clear here but looking on the usual spares sites the mechanism looks pretty complex. Also I see that some of the main parts are no longer available. I’m not usually heavy-handed but don’t want to tempt fate and break something I can’t replace. I’d appreciate advice on whether it is worth stripping down or should I just give it a surface clean and leave things be?
Cheers, Colin.

[Gfhug]

Colin, have you read this about the handbrake upgrade?
http://forum.etypeuk.com/viewtopic.php?f=9&t=6170
Note also the comment about an improved version from Barratts

Geoff

[mgcjag]

Hi Colin....not sure what your refering to........many on here have completely stripped the irs of all its parts.....its unusual to brake something. .....if ont avsilable from the usuals then a post here in the wanted section or ebay should get you what you need.....if your ok with it as is then just make sure everything operates ok..posting photos helps us help you...Steve

[Philk]

If you are doing the IRS, it is also worth considering having an Easy Bleed kit fitted to aid any rear-end brake bleeding that needs to be done in the future. I had this done when our IRS was rebuilt a couple of years ago

[colinevans]

Thanks Phil, I’ve got an easybleed from Rob Beere ready to go, it definitely seems sensible.
Steve, I was referring to stripping down the handbrake mechanism to replace the return springs inside the carriers, I believe the carriers themselves are no longer available.. I assume you are saying its simple enough to do. I was just asking for an opinion as with all most all of the jobs on this project I haven’t done it before and so wanted to check it was straightforward enough for an amateur to do.

[mgcjag]

Hi Colin..ok think i know what you mean now....the return springs between the operating lever and the carrier. ........and all acting as part of the self adjusting mechanism.......i would at least open up clean out all the old dirt/grease......and check the operating mechanism. ......note the levers are handed and must go back the same way as removed......so have a good look and photo them and note the different angle of each one befor removeing........the springs might look rusty but should be ok if cleaned up.....Steve

[colinevans]

Excellent thanks Steve, will do.

[johnetype]

Colin, on the subject of the orientation of the slots in the large radius arm bushes, have a look through the posts on here. Certainly a while back the consensus was to rotate the bushes by 90 degrees so the slots were at the sides rather than in line as originally fitted by Jaguar. The rationale for rotating them is to minimise rear wheel steering under load but I suggest reading the posts and make up your own mind. I installed mine rotated by 90 degrees.

[colinevans]

Hi John, coincidentally I discussed this subject with Alan Slawson when he rebuilt the diff recently, as I was unsure which way to go. His view was to leave them as per the manual, i.e. inline, unless I wanted a slightly stiffer feel in which case rotate them through 90 degrees. Thanks for the input, I’m leaning towards his view but still considering it so will have a read!