Well its now out .....
Thanks to the all the forum members that have documented how its done.

I had already removed the A frame as it was gone with rust (new to me refurb one ready to go back in)
As i have some welding to do i decided to remove all the sub frame, my next step was to remove the 4 exhaust bracket bolts, then the hand brake cable.
Then i supported the sub frame with a jack and some plywood bolted to the diff using the longer 2 bolts from the A frame (as documented by another member)
Next was to remove the prop shaft bolts (after marking it and the diff flange for refitting, as documented by another member)
I then removed the brake caliper's and discs to reduce the weight (as documented by another member)

Next was the rear shock top bolts/nuts, at this stage i decided to remove the rear shocks completely so i removed the rear ARB and then the shocks, now with the shocks removed i noticed there was much better access to the 4 exhaust bracket bolts (bugger!! it took me 3 hours or more just to get the 4 exhaust bracket bolts out)

Next was the 2 top mono strut bolts, i noticed this mono strut may catch with my exhaust when i lower the sub frame/diff so i decided to remove the bottom bolts also and remove the mono strut from the subframe before lowering .
With all this stuff removed from the subframe it should be much lighter now.

As i started to lower what was left of the subframe...lol..
it came out easy, and once on the ground easily manoeuvred and pulled out from under the car.
Not sure yet but after iv done the welding to the drop leg's and refurb of the IRS i may re fit as i removed..



Drop leg that needs welding.

 

Sadly all too common.

 

So sorry to see the rust. UK's wet climate and salted roads are car body killers and a 20 year old Jag is no exception.
What's now on the "To Do List. " Any particular treatment - galvo / sealant etc?

 

Oh my!! Makes me even more grateful for my California all it's life car. I believe I have no such issues anywhere under my car. I don't drive mine in the bad weather here in Ohio (usa) to preserve it as long as I can. Best of luck to you.....you dedicated faithful owner. TM

 

When i first started fixing the rust problem i was using other treatments, but now i use Dinitrol products rc 800 / rc900 and the ML cavity oil and the rustbuster 121 epoxy mastic. I only use the rc800/900 in areas i cant clean really well and cover with 2 some times 3 coats of the 121 epoxy mastic.

The to do list.... well im working my way around the car.. floor pans, sill/rockers, etc.
Im going to sort out the rear drop legs and any other areas i come across while the rear sub frame is out, and refurb the hole sub frame before it go's back in.
Lots to do..

Today iv cut out the left side drop leg rust....


I opened up the layers of metal so i could get the rc900 right in between them, and then closed them back up.



I will give this area a good spray with upol weld through primer (forgot to mention this product David). Before welding ill clean the weld area back to clean metal.

I also gave the inside of the drop leg box section the rc 900 treatment, and later after all the welding is done i will give this box section a good spray with the ML oil.

Access to this box section is easy, you can remove the bolt from the "A frame bush" and get in from there, or you can remove the bump stop and use the bolt holes for access to the rear and front of the box section, from the bump stop you can do the full length of this box section.



Showing the length you can reach inside the box section ..


Hope this helps people that like to do preventative maintenance ..

 

That doesn't actually look too horrid, so maybe she's giving you a bit of a break?

I found another entry under one of the metal-backed bitumen seals here:


...although it's likely too small to get a spray nozzle in there.

Probably not of much value as the rot seems to be outside-in due to the **** seam sealing in this area?

 

Yes michaelh, Its not to bad and i hope the old girl is giving me a bit of a break, looking at the areas i did on the right side this left side looks much better, but the rear closure and sill area in front of the rear wheel dos look as bad unfortunately.

This drop leg laird metal box section is very poorly seam sealed and has no panel bonding glue to help keep the water out between the lairs as i can see.
When i put the rc900 in the box section i did see it coming out along the section just under the bump stop through the seam,
When i sort this area out it will get well seam sealed and covered with the 121 epoxy.

As you can see, under the bump stop there is no seam sealer.

 

Nothing to contribute ....... except sympathy and best wishes.

Graham

 

The left drop leg is now done.

First patch welded in, (lots of weld through primer behind the patch)



Over the top of this, and the back of the second patch, i applied some 121 epoxy.
Next day the second patch got welded in place,
I used some panel bond over the first patch area and to the back of the second patch, then put them together and welded it in place.
Gave the repair area a good clean and applied the first coat of epoxy 121 (another two coats will be applied over the next 7 days)





Iv also managed to get the rear subframe striped down and the diff out.


Next job will be the right side drop leg, this area i had a local jag independent do some welding repair work about 2/3 years back.
Well im going to have a look, to see how good of a repair he did actually do ..

 

XKR-DAY,
Doing a great job.
When I had my Diff off, I cleaned the Aluminium cover and repainted it (Ali spray enamel). I read that the cooling fins should be clean to help dissipate heat and prolong the oil life.

 

I'm sure you will find they haven't put in the same attention to detail as you have.

 

Well done....

 

Thanks, Im on a large learning curve with all this, trying really hard to do the best i can for the old girl....
This site is full of experienced members, and what im doing would not be possible (with out me following in the footsteps of other members)
So a big thanks to ALL .

 

Hummm !
Lets see..

This is the repair i paid money for .

Now with the crap removed and cut open .



Yes RD.. your suspicion was correct....
NO rot removed or any protection to the back of the welded panel. all done by a so called professional !!

This side has a lot of thick rust scale between the lairs, so i had to cut a lot more out to remove the rust.
I removed both lairs, back to the internal C channel .


I also had to remove the abs/brake line bracket to do this, now with all the rust removed .



After cleaning, i have temporally covered this area with weld through primer to stop any flash rust.
Iv now got to make the repair patches.
I will be making them from galvanised plate, i have some 1.2mm and 2.2 that im going to try and use.

 

Typical of garage welding "to get through an mot", I have found they will do the minimum to fix/hide the issue. Can't blame them really, most punters just want to get through the next MOT, if you look at what they would need to charge to do the job properly, the cost would be too high for most cars/punters.

So for a back street garage I would say typical/understandable. If it was done by a restoration/specialist shop, then they are cowboys.

 

Yes i understand what you are saying..i would not go as far to say "restoration/specialist" but more jag independent, never the less i did expect better, when i looked at there web site and seen the repair work they had done to other xk8's that is what i thought i would get.
Anyway im happy to do this work my self now, and save the big £$£$£$£$ ...

 

The first repair patch has been made out of 1.2 galvanised plate, Iv drilled some 8mm holes so it can be spot welded to the C channel (as original)
And butt welded to the rest.
Iv removed the temp weld through primer on the C channel, and used the spot blaster to remove any unseen pitted rust, and to give a good key for a coat of the epoxy 121, as usual the back of the repair patch will get a coat of epoxy also.

Spot blasted area..

Then epoxy 121..


I will remove some of the epoxy at the weld areas, and replace with weld through primer just before i weld the patch in place.

The repair patch..



Next job will be the welding of this first repair panel and fabricating the second lap panel, all time consuming, just the above has taken me 5 hours to do..

 

Very disappointing that the repair was little more than a cover-up, but the cost of 'doing it properly' just doesn't make commercial sense (yet) given their value. There is an excellent restoration company here, and their work is superb. Down side is that they charge a minimum of £75-£80 p.h.labour. At those rates, the work you have done on this section alone tots up to around £400.

Keep up the good work

 

The right side drop leg, is now all sorted...

The first repair patch welded in place and painted with epoxy 121


The second repair patch made.
Then welded in place and painted with epoxy 121



The repair will get another coat or epoxy 121 (in about 3 to 4 days)
Then i need to weld the abs/brake line bracket back in place, im also cleaning up any surface rust under the car while the sub frame is out and painting the area with the epoxy 121, (iv had a look and it all looks good under there, some slight surface rust in places)
All the seam sealer will be checked and removed/replaced where necessary, then when all sorted both drop leg/chase box section's will get lots of ML oil sprayed inside.

Also started to de grease/clean up the rear sub frame. After reading Racediagnostics thread and lots of others, iv also decided to leave the wish bone fulcrum bolt in place..... after 2hrs with the needle gun, then another 2hrs with the wire wheel on the grinder its looking ok.


It will now get two coats of Dinitrol RC800, then two coats of epoxy 121, I think i will (like RD) take the rest to get sand blasted (as this is hard work!)

 

Both your patience and results are impressive - well done.

You're joining the band of people who've turned their rear suspension into works of art.