IRS refurb

[mgcjag]

Hi All......just removed the IRS for a refurb (in good time as one of the mounts had parted)......advice needed for removing the inner & outer fulcrums, the manual shows dummy shafts being inserted to retain the bearings, spacers etc.......what have you used? or can i just reasemble without?....Also the diff outer shaft oil seals are leaking, any problems in renewing or should it be straight forward. Finally Ill be fitting new discs & assume this will affect the spacers required between disc & half shaft & thus the camber angle...is there any way to asses this prior to re installing the IRS & then having to add/remove spacers....Surely at the factory the IRS was built & installed? or was it then reajusted.....Thanks in advance..Steve

[1954Etype]

Hi All......just removed the IRS for a refurb (in good time as one of the mounts had parted)......advice needed for removing the inner & outer fulcrums, the manual shows dummy shafts being inserted to retain the bearings, spacers etc.......what have you used? or can i just reasemble without?....Also the diff outer shaft oil seals are leaking, any problems in renewing or should it be straight forward. Finally Ill be fitting new discs & assume this will affect the spacers required between disc & half shaft & thus the camber angle...is there any way to asses this prior to re installing the IRS & then having to add/remove spacers....Surely at the factory the IRS was built & installed? or was it then reajusted.....Thanks in advance..Steve

Steve, use a length of 15mm copper tubing as a dummy shaft.
I know it is possibleto change the front diff oil seal without major stripping but am not sure about the outputs (can't think why not)
The manual has details about making a link which sets the suspension at the correct height for checking camber. I bought a cheap one that is really effective. Just be aware that you will probably spend a lot more on this refurb than you originally budget for as you will fall into the 'While I'm at it.....' trap!

[PeterCrespin]

Disc replacement alone will not alter the camber to any measurable degree (pun intended). The disc thickness is accurate enough not to matter in terms of readjustment. The camber shims are needed to allow for diff/cage tolerance mixtures, not disc swaps.

[mgcjag]

Thanks guys....the 15mm copper is great....re the setting links for the camber angle the manual shows using this once the IRS is fitted back on the car then having to remove the springs/shocks to adjust shims.....is there no way to set the IRS prior to installing?......Steve

[1954Etype]

Thanks guys....the 15mm copper is great....re the setting links for the camber angle the manual shows using this once the IRS is fitted back on the car then having to remove the springs/shocks to adjust shims.....is there no way to set the IRS prior to installing?......Steve

Steve,

yes there is (I and a few others have done it). You basically have the springs and shocks removed, replace them with the link, check the angle and reset as required.

Pete, is this something that the ex racers on the 'other forum' made by working out the length? (Memory fading....)

[PeterCrespin]

You can easily set rear camber with the IRS off the car as Jag did when building - you just use the setting link instead of the spring/damper unit. The distance between centres is 8 & 3/16" IIRC, best check the manual. Probably around 20-21 cm. It's not critical, frankly, since all settings are a compromise anyhow. Just so long as it's close.

The only extra issue when doing it off the car is to remember to have the IRS the right way up (more than one fool as set it while upside down and got their camber the opposite to what it should be).

This assumes you have the IRS cage dead horizontal of course - easily verified using a builder's level on the cage itself and across the top of the tapered fixing bolts as a second check in case it's a bit uneven. This is doubtless where Jag scored in having a set of level rails or a surface plate where everything would have been assembled accurately without messing about on the garage bench with wedges, or whatever.

There is another way of doing it that doesn't rely on a level surface so much, or even a camber gauge. You use trigonometry to predict the distances off the vertical of a straight edge across the hub face, at a given distance from the wheel bearing centreline. If you've got your sine/cosine tables handy it doesn't take long to work out. Al McLean had a few nice photos on his J-J photo album of an XJ6 IRS being set up this way IIRC.

[mgcjag]

Thanks Guys..just a matter of getting on with it now.. will report back when completed & let you know how it went .Steve

[Tony]

Nice carpet Steve. Is it an Axleminster?

[1954Etype]

Nice carpet Steve. Is it an Axleminster?

Groan....

[44DHR]

Steve,

Another IRS rebuild tip to remember is that when you refit the 4 upper damper bolts, make sure you fit them from inside outwards with the nuts on the outside.

An easy mistake to make when the cage is out of the car. Once installed back up into the car you cannot remove the bolts outwards if for any reason you had to change the shocks.

It will become one of those jobs where you go through the whole axle, especially to get that damn handbrake self adjustment to work !!!

regards,

Dave

[vipergts]

Nice tip....especially as I'm putting mine back together as we speak

[mgcjag]

Hi All just hit the first problem? which way does the nut in the centre of the splind hub unscrew? is it the same way as the spinners ( opposite for each side)? thanks steve

[vipergts]

Just anti-clockwise on both sides

[mgcjag]

Hi All....IRS now stripped & the cleaning starts. All very straight forward accept for pulling the rear hubs off their splines, had to visit CMC & have them use the hub removal tool, even with this they were tight right down to the end. Dismantled the callipers & advice needed on refurbing........Its clear they have been painted in the past as brake fluid has stripped the surface in places. anyone repainted with calliper high temp paint? or had them plated? Thanks Steve

[mgcjag]

Hi All......IRS refurb is now complete & installed back in the car...callipers, & all handbrake parts were zinc plated at home using a kit following the advice previously on the forum on home zinc plating.......Re fitting the IRS back in the car proved to be quite a challange to get all the mounting holes lined up.....advice to anyone doing this job would be to trial fit the stripped down cage & mountings. Set the camber angle with the IRS on the bench following advice from CMC for a road car to 1/4 negative found this best done with a straight edge across the top pf the cage with a setting link in place & using a large set square off the straight edge & down across the face of the hub to achive 90 degrees by adding shims...then removing shims for the req angle ( see manual Think it was .020 for 1/4 degree) Next job the front suspension Ill be in touch.
All the best Steve

[MarkG]

Fine job. Well done. I'm doing the same job now. Did you tot up what it cost you in parts and specialist help? My wallet is being drained at a rapid rate!

Mark

[mgcjag]

Hi Mark......will work out the cost this week & post asap. Steve

[mgcjag]

Hi Mark......Just worked out the cost ...Approx ?700 Parts inc new springs/shocks/discs/calliper pistons/seals/brake & handbrake pads/IRS mounts/swing arm bushes/anti roll bar bushes/brake pipes..ect all parts were standard & not uprated versions.....?170 for having all parts grit blasted & ?70 to have the hubs pulled off the splines so total approx ?950.. Hope this helps......wonder what it would have cost at a work shop. Steve

[Heuer]

Done at a work shop, about double your total.