No need for it to be death sentence, I have now repaired and replaced several TD5 chassis rear Sections. Got the templates all made up and even repair the crossmember too which is always rotten. I remove all the piping and wiring, the Rear bumper, Towbar (if fitted),Rear Exhaust section and fuel Tank.
I then cut away all the interior chassis section where the fuel tank used to sit as far forward as the first crossmember and fit the new 3mm replacement plates cut to the same dimentions as the originals. Then I add bracing across the plates and also acros the back of the chassis holding the bumper mounts and rear body mounts in place allowing for easy relocation.
The Chassis is then cut from the vehicle just rearward of the crossmember, the body bolts undone and the chassis removed to the bench...the rest of the old chassis is then cut away on the bench and replaced with the new sections again in 3mm steel and seam welded with red oxide coating to the inner panels before final seam welding ( I know a lot will get burned off but youd be surprised how much stays in place) the Tow bar mounts are then added to the chassis rails along with al the other ancillary brackets etc and the whole thing coated in red oxide.
Next the new chasis section is offered back up to the vehicle and seam welded back in place..for extra strength ive started adding cheek plates over the welds but it really is over kill..all threads are retapped(they always need it) and the chassis is then oil sprayed from the open ends at the rear..all components are refitted and its as good as new, infact its better and will outlast the rest of the vehicle.
I have one in the workshop now which is in terrible state (I think it was made from some chocolate they borrowed from down the road) and will upload some pictures when I have finished so you can all see the finished article, and of course how it looked before.
Also have done the front chassis sections just as it goes under the floorpan these always collect water and rot away from the inside, they are a real pig to do but the end result is worth it. Yet to see a TD5 Disco chassis that isnt showing the effects of tinworm why they built the chassis from such poor metal is a mystery..I have a 96 300TDi i run and the chassis is mint..unfortunately the floorpan fell to bits along with the inner wings so all that was rebuilt too, TD5 Bodywork is like new but chassis rots Go figure that one???.
Steve
Minivation