So I decided to work on the rear rocker on my 97 today. Was hoping to drill some holes where the rusth bubbles are starting and then fill 'em with some motorcycle chain lube then put plastic plugs in. Problem with that was that the lube quickly came back up and out the holes. Cut it open and got a good 5 lbs of dirt and muck out so now I'm doing it the "right way" Cleaned it all out made a nice patch, have naval jelly on the inner now which I will paint with a rusty metal converter paint etc. My question is as I don't know is where did all the dirt and crap come from? Is it coming down from the rear window then getting stuck in there or what? Should I be enlarging the drain holes so that more gets out? Don't want to do again for a while as next time I'll probably have to buy the full patch panels. Thanks!

 

There is a big plastic vent in the rear left wheel well behind the tire. It can let a lot of dirt, sand, and water in and rot that section of metal.

 

yep there's a vent on both sides, huge great things to let the air out when you shut the boot. there should be a thin rubber sheet to act as a bit of a valve, but the crap still gets in.

 

Where exactly is this vent. I found the one right in front of the wheel (well a plug but that is for the inner rocker area). There looks to be a big metal plug covered up with undercoating but again, I don't think it will go into the little area between the outer rocker and the inner rocker. I'm guesing if it is a vent though it isn't like you could just cap it without other issues starting right? Also, is there a similar vent on the pass side? That side will be next.

 

Are we talking in front of, or behind, the rear wheel ?
Behind the real wheel, on the inside of the steel wing panel (above the plastic bumper) there's a rectangular vent which lets crud get into the lowest recess of the boot (trunk) sides.

In front of the rear wheel, depending on whether it's a coupe or convertible, there are various plugs and welded "caps".
Unfortunately, none give access to the very small gap ( a few millimetres) between the outer panel and the inner panel. There's a flexible sealant between them over the rear wheel arch and that sealant is now brittle and probably not there any more - hence the ingress of mud and water.

 

Never thought about the area behind the wheel as a rocker so no we are right in front of the wheel. The inner fender is clean and dirt free, the small gap was filled with crud all the way up which I don't see how that would happen unless it comes from above. When I washed it out I didn't get any water coming out along the lower seam in the wheel well. The wheel well seam all the way up seems quite solid.

 

Not sure if this will help at all - quite difficult to explain but this might be worth a look :

Paragon Design UK - Jaguar XK8 & XKR Restoration

In the convertible, there's a steel tube - bit like a scaffold pole - that runs from front to rear and has round metal caps on each end.
The front of the rocker / sill is just two skins but from the weld in the middle under the door, there are three.
The gap between the outer and "middle" skin starts at zero with the weld, and is just a few millimetres by the time it gets to the rear wheelarch, and it continues right over the wheel arch to the rear wing panel. These two "skins" are not welded, but were bonded together with a sealant which, if yours is like mine, have hardened and degraded over the last 18 years or so, and, in one or two places, have fallen out.

 

ah my apologies I was thinking of behind the wheel wrt the vent, I may have confused the issue. The vents cause rust of the rear of the wheel arches from the inside out.

 

I am wondering if the debris that came out when the thread starter opened up the panel was this degraded sealant to a large extent.

Curious whether the upper seam of this triple layer panel is open at a vertical edge. This would allow water infiltration and give a possible angle for rustproofing from inside the vehicle structure.

 

This photograph gives an idea of where the double skin areas are

 

Thank you, now i see how they assembled it. The inner layers do not all appear to continue to the lower pinch weld. Corrosion is probably due to the moisture and debris and salts keeping the environment damp and active. It would be a real nightmare for rust prevention if they all continued to the lower pinch weld. Flushing the rockers out and directly applying rustproofing to the area on a bi-yearly basis would probably eliminate the problem. Perhaps even adding a lower plug for access might be a good idea, however drilling holes sometimes starts problems.

 

Unless the degraded sealant turns into "garden soil" No. Still don't see how it filled up with soil and filled up high not low in the rocker.

 

Every car is different, however in many cases convertibles allow a very small amount of debris and water to enter at the quarter window seals. This is inevitable regardless of how well designed or the condition of the seal. This finds itself in the rocker panels by design and eventually the drain ports. Some vehicles have a continuous connection from the cowl scuttle to the rocker panel which is often contiguous front to rear. Regardless of the efficiency of the scuttle strainers, some organic material will wash into the interior spaces. These very small amounts build up over time.

In many cases the angle at which the vehicle is parked can affect where something will deposit not to mention air currents driving debris into unnatural spaces. I was once cleaning out the interior areas of a body only to look up and see material caked on the underside of the upper quarters in a relatively clean area with no obvious openings to cause splash.

It is necessary to regularly flush out these areas and apply corrosion prevention. The issue is access and the necessity of disassembly and often modification deters most owners.

 

Hi,

I’m researching rust issues prior to my 2001 coupe going for rust prevention treatment. I’ve seen the photos in this thread and looked at paragon restoration photos.

can anyone advise in the best way to get at the areas to protect them?

For the rear arches and sills where can I get to inject the cavity wax?

for the front floor what is the best way to stop the water getting up passed the bung in to the car?

is the front crossmember a hollow section that needs injecting or just a surface spray of wax?

if any trim panels need taking off to do it properly I will do it before it goes.

thanks.
kevin

 

In reply to Kevin
The sills have plugs at each end that you can use to inject cavity wax. If you remove the tread plates then there's also access to the middle of the sills.
Front floor corrosion is caused by a plate below the floor that was used to carry the body around the factory. These plates aren't sealed and collect crud, which eats into the floor. Many people take them off before the floor becomes affected.
The cross member is a hollow section. I treated mine by de-rusting and painting the outside and used cavity wax inside. The cross member has a number of access points.
Don't forget the inner wheel arches, which have a hollow section that rots behind the suspension uprights. If yours is still sound there is an access point in front of the suspension, behind the liner, which you can use to get cavity wax in.

 

Thanks RichSP.

Does your comment, “Don't forget the inner wheel arches, which have a hollow section that rots behind the suspension uprights.” Relate to the front suspension?

Also at the rear chassis I’ve read about a suspension mount that has multiple layers of steel. Hopefully I have attached a picture. What’s the best way to protect this? Is it possible to inject something in and fill it up with wax oil?

From Paragon Jaguar XK8 restoration website.

 

Hi Kevin,
This is worth a thread in its own right as we're going off topic from the original one. You're right, I meant the front suspension, but I've not tackled the rear suspension leg, so I can't help with that - sorry.