Sleeving front frame rails?

[joflaig]

[This is not a rotiserie restore situation. The car is all put together, minus an engine at the moment]

I had some rot in the left front frame rail. There were dime size holes and pitting in a section about 5 inches long right in the middle of the rail right where the k-member starts. The resto shop cut out the rot so there is now a rectangular hole on one side about 1" x 5". The outside face of the rail, kind of in the area where the shock is also has some smallish holes and is thin in spots. They said they thought there seemed to be the remains of a mouse nest.

As part of a fix they actually propose sleeving in both front frame rails. Here are the optons they gave me.

As far as the frame rail patching, exactly which plan do you want? To patch the hole and sleeve just the area around the corrosion w/o dropping the K member (we would fabricate the sleeve) or the patch the hole and drop the K member and install the sleeve that runs most of the length of the visible frame rail (we would purchase this sleeve-comes as a pair, left and right sides)?

The rational on frame sleeving the right side as well as the left is that the corrosion on the right side cannot be too far behind the left side. You can either do them both while it is this far apart or take it apart later to do the right side. It will definitely stiffen the frame up more if both sides are done vs. doing just the left.

My question is if there doesn't seem to be any visble corrosion on the right side is it really nessesary to sleeve or are they being just too cautious (or thourough)? Removing the k-member and putting it back won't be cheap labor-wise.

I know, sorry no pics!

[charger50071]

Why can't they just weld a patch over the damaged area and call it a day?

[joflaig]

yeah, that's my basic question. My inclination is to basically just have them patch the hole and sleeve just the area around the corrosion w/o dropping the K member.

[Mike DC]

   
You could drill a few small holes in the questionable areas on the other side rail to check for the real remaining thickness of the metal. 

On the driver side, the battery/tray area is enough to cause premature rot in the rail below it.  I'll bet that's the only really bad area. 


   

[Charger-Bodie]

with the engine out allready, dropping the k-frame ist much of a job.

Id want it out so there isnt any stress from it while welding in that area either way.

[hemi-hampton]

Like Charger50071 said, Why not just patch the hole & call it done. Thats what I did on the Black T/A I restored. But the rest of the frame rails were pretty solid. Unless the rest looks weak, If looking weak then go with the Auto Body Specialist Caps. These are good for the non show car look.  LEON.

[joflaig]

On the driver side, the battery/tray area is enough to cause premature rot in the rail below it.  I'll bet that's the only really bad area. 

I think you may have hit the nail on the head!

[NMike]

if they are small holes, use a hole saw that is the right size. cut out the spot. then cut a patch with the same hole saw. perfect repair plug.

[bill440rt]

I think the shop is getting the definition of "sleeving" incorrect. When replacing a frame rail, the term "sleeving" applies to fabricating an INNER sleeve to promote strength when replacing the part. Think of the frame rail as a large letter "U". You don't want to butt-weld two pieces of a frame rail together. When replacing a rail section, after the rail is cut off a smaller "U" shaped sleeve is inserted into the old rail & a new section is then slipped over the sleeve. It is then all welded together.

I think the shop's method of repair is called "capping" instead. You DON'T want a patched up hole on the frame rail! We're not talking about patching up a small hole in a fender or a trunk floor. This is a FRAME RAIL, for Christ's sake.

Cut out all the rot completely.   If it means cutting out the shock tower, then so be it. If you have to find a donor rail or shock tower from another parts car, so be it. This is a major safety concern. If he's gonna put a cap on it, make sure the metal is of a significant thickness. I would still put an insert in the rotted rail behind this cap for strength as well.

And, drop the K-frame & front suspension to do this repair. You don't want that stuff in the way. It's really not that hard of a job to do, especially if you're going to rebuild the 40-year old stuff anyway.

[joflaig]

Just an FYI...


I ended up getting the full frame rails caps from Auto Rust Technicians, for both lh and rh. They sell a front "front" rail cap, but it's only about 30" or so and didn't extend enough past the area that was corroded. The battery tray area did turn out to have some corrosion which probably contributed on the lh and the metal was thinning in parts on the rh side.

The shop is going to cut out the bad stuff, cleanup the corrosion and treat the metal in such a way that there should not be any rust issues despite the caps (I know people may disagree with this).

I hate adding the caps since people might look at it and assume the car is a rust bucket. The guys at the shop didn't seem to think this was such a big deal and were  actually kind of stoked that the frame would really have some added strength, particularly where the rails go under the firewall. Since I'm dropping a stroker in there with as much 600 fp of torque and 525hp+ I know that can't hurt, but stock rails are more than likely able to handle that without issue (correct me if I am wrong).

Now if I could, I would have replaced both front frame rails. However, since I don't have the skills to do this myself this is much, much, much cheaper... Yeah, one day when I do a real nut and bolt resto then maybe I replace them with original rails, but since I have no plans to re-sell and the caps do add rigidity, I don't know...is it so horrible?

[Mike DC]

 
I don't see any big deal in the big sense as long as you don't unessecarily cut on the car.



Cutting out just the truly weak/rusted sections of the old rails?  It was gonna have to happen either way.

Capping the rails with new metal?  Seems like it could probably be ground/cut off a few years later.  That would leave you with just what's left of the original subframe rails again.  Not better than if you didn't use the caps right now, but not really much worse either.