Thursday, June 11, 2015

A Fix For Land Rover Discovery II Frame Rot / Rust



Last year I wrote a story about the frame rust that is beginning to cripple Discovery II trucks that run in snow country, particularly the 2003-4 models.  At the time, the only fix was a new frame ($10,000+) or hand fabrication and patching (costly and not always successful.)  Today I am pleased to show a new and more affordable alternative.

Rovers North has begin selling rear frame sections that replace the last two feet of a Discovery II frame.  These premade sections have all the complex fitments that make one-off fabrication difficult, and they are easy to install (at least compared to the alternatives!)

Here is what a rotted frame looks like, pre-repair:


You don't see much damage from a distance but when you look close the rear frame rails are totally destroyed.  This happens because the rails are thinner than older Land Rovers, they are not protected inside, and they are designed in such a way that gravel can get inside. When that happens, salt water from winter roads soaks the gravel and the mix just eats the frame from inside out, but luckily only in the gravel spray areas behind the wheels.


In some cases the shocks towers corrode, weaken and break.  We see other issues like that but the main failure is what you see above - rot in the rear two feet.  Here's how we repair it now:


We remove the gas tank for safety and access. To do that the trailer hitch has to come off.  We usually send the bits of hitch for sand blasting and finishing – preferably powder coat for its durability.

The truck is set up on a body lift and the rear of the frame lopped off. Here is what the rotted segments look like on the floor:




The edges are smoothed and any corrosion extending forward is repaired.  Then the new frame rail ends are installed.  You can see how they slide over the original rails, and the six holes on each side give space for bolting and welding. 






The gold finish on the frame is a weldable corrosion resistant primer, so the repaired frame won’t be so quick to go the way of the original.

The rear crossmember will take some fabrication as you see, but it’s not a big deal.



These frames also rust and break alongside the right catalyst, and we repair that with plate to strengthen the sides and bottom of the frame for about two feet in that area.  Once the frame is repaired we still recommend treatment with Waxoyl.  The Waxoyl may not hold on badly rusted and flaking areas but it will significantly slow the progress of corrosion most everywhere else.  It's not optimal - applying on rusty frame - but it's the best post-repair preservative I know.  The image below shows a repaired area treated in Waxoyl:


We are very pleased to see these new frame rail repair pieces.  I predict they will save quite a few truck from the scrap yard!

(c) 2015 John Elder Robison

John Elder Robison is the general manager of J E Robison Service Company, independent Land Rover restoration and repair specialists in Springfield, Massachusetts.  John is a longtime technical consultant to the Land Rover, Mercedes, BMW, Porsche and Rolls Royce Owner's Clubs, and he’s owned and restored many of these fine vehicles.  Find him online at www.robisonservice.com or in the real world at 413-785-1665


2 comments:

Ian Ward said...

Great to see, considering the problem areas on the frame are so specific. What is your shop charging for this repair?

John Elder Robison said...

Ian, we have half a dozen frame section repair pieces to choose from, and there is often a need for fabrication in spots. Repairs can range from $2,000-$6,000 which is in every case far less than a new frame would cost.