Cracking in "C" pillars (1 Viewer)

[JAPFPE]

Me too..

Ironically, I ran out to take a look at the LX after reading Dan's post and the replies. I had noticed yesterday what appeared to be a rust stain just to the aft end of the side window bottom trim moulding. I had been toying with the idea of disassembling the window moulding to see if any rust was present under the molding. Within 10 seconds I too identified that the "C" pillar is cracked as Dan described on the DS. It only appears to be a millimeter orf so in length. The PS shows no sign of cracking.

 

[concretejungle]

Have their been any reports of this crack worsening? How much is in known to spread? So many questions.....i'll go search..

 

[RavenTai]

Does anyone know if drilling holes at the very ends of the crack will stop the spread of it? I ask because this technique is used in fiberglass and seems like it might be applicable here.

Ary

It is called "stop drill" (verb) not to be confused with a “drill stop” (noun), we do so to cracks in aluminum aircraft structure, then apply a patch over it to get back the strength lost to the crack. You would need to find the true ends of the crack though.

first we remove the paint and use dye penetrant, you will see the crack extends past the part you can see with the naked eye, then drill a hole at the end(s), NDT comes out and does an eddy current inspection to make sure the end of the crack was caught and then the hole is enlarged to remove any stressed metal that may not have been caught by eddy current because it is not cracked yet, a reamer is used for final size to get a bur free hole,

But a stop drill will not stop a stress crack unless you regain the strength with a patch

I just went and looked at my 96 and I have chipped paint and something that may be a crack but not as apparent as Cdan’s both sides, so much for this being a 91-94 thing

After looking at it I think this crack started during manufacture, the radius of that bend is way too tight, there is almost no radius at all. If it were aluminum it would have cracked in half on the spot when it was stamped, steel is a little more ductile but still needs some radius. This may be good as a pure stress crack implies the part is seeing more load than it can handle requiring a repair that will make it at least as strong as it was before the crack, if the crack started during the stress of manufacturer now that those stresses are gone we may be able to get away with a weakened part not cracking further.

E look again my 96 looks just like the pictures above, the scale threw me off at first. It is a very close up picture. Follow the trim under the rear window foreword to where it ends,

I think a weld inside and out with the exterior one being ground flush is the best repair but it will have to be repainted afterwards. The trim would have to come off possibly also the window to prevent heat damage.

Stop drill and large thick fiberglass patch on the back to reinforce the crack would be the next best but still need at least touch up paint. I don’t think this would be as reliable a repair but you can do it in your driveway.

Most adhesives are somewhat flexible, they move slightly with the panels, here we need something rigid.

In the mean time add “slam rear doors” to “pull in reverse” as things never to do in an 80.

 

[concretejungle]

Nice raven.

 

[Nomis]

Just checked my 96 LX and although the bend appears the same, I don't have any bubbling/cracking of the paint - or rust. Maybe it's just a matter of time, but for now it's rust free - at least visibly. I use the factory rack and my Yakima from time to time to carry 120 lbs of kayaks. I was wondering if they may have used the better bodies for the LX. Since '96 was the first year for Lexus flagship SUV, I'm sure a lot of extra attention went in to it - maybe??

 

[landtank]

I was wondering if they may have used the better bodies for the LX.

Absolutely, they part graded ever aspect of the LX and only the best of everything was used when they were assembled. Wish I had known that when I bought my truck.

I unfortunately got the leftovers.

 

[Darwood]

Just decided to check to see if I have the cracks and sure enough, here they are:

I guess the 95+ thing being immune is a myth.

 

[Bryan E.]

Quick, someone get a IH8MUD sticker designed to go over this area.

 

[landtank]

So what is the danger of these cracks. Let's skip the whole rusting into oblivion thing, how bad have these cracks gotten and how dangerous will it be to carry loads on the roof.

 

[erics_bruisers]

was your vehicle repainted, darwood?

i don't even want to check on my 80s --

e

 

[IdahoDoug]

I have a slightly different theory to posit on this. My bro in law is a suspension development engineer for one of the biggest Detroit firms. He's ridden in my 93 80 and my other brother in law's 93, and my 97. Without any prompting on my part, he confirmed to me once that the 80 has a sympathetic flex in the frame due to the suspension (everything from wheels to top of spring is included here).

Have you ever noticed that your 80 will tend to "jiggle" on the freeway with very little encouragement from the pavement? What you're feeling is the frame flexing a bit, causing the body to flex at a high frequency with a considerable amount of structural force. You tend to feel it in the seat, and will not feel this particular thing I'm speaking of in the steering wheel except as residual cowl/firewall shake (very minor - not like a front wheel out of balance).

So, the entire greenhouse (from the bottom of the windows up) ends up getting the worst of it as it creates a slight whipping effect. We've discussed it a couple times and he agrees with me it originates with the front suspension and is easiest felt in the driver's seat. This now agrees with most people's finding's it's on the driver's side C pillar - interesting.

To minimize this, he feels several things should be attended to:

Watch roof loads.
Different spring rates (example: OME kits) may cause the suspension to cycle at a different rate that is not causing the sympathetic shake of the body/greenhouse.
Don't run old shocks
Certain tires may cause more of this simply because the tires are part of the "spring" of the suspension from an engineering perspective.
Certain tire pressures may also do this.
Check that your body to frame bolts are all tight and if possible new body mounts will likely change or help this. In point of fact, I do not remember my 80 doing this when new.
Heavy front bumpers may change the front frame's flexing - good or bad.
A shock tower brace should be considered/engineered.
With age of bushings/body mounts it may get worse.

Funny that this was a post I've been planning to make for a few weeks. Let's discuss it.



DougM

 

[cruiserdan]

'K Doug, sounds like you have a suspect cause. Do you have any thoughts on the best way to repair the body?

 

[IdahoDoug]

Dan,

I agree with your comments about the die work and resulting stress riser at that point due to the shape, and it's unfortunate location at a point of key stress. Someone with welding experience could answer this, but doesn't even top notch welding cause a degree of brittleness to the welded area - especially with thin gauge like sheetmetal?

In the absence of changing the cause (forces sufficient to flex this area), I don't see a way to add enough strength to this area to spread the load yet. I *think* the motion is a back and forth wiggling of the roof, so with a lever arm the height of the C pillar that motion is going to continue and I'd hate to see someone put something there only to see it crack that material. Personally, I'd be curious to see what's inside there. If there's a way to weld a piece of sheetmetal or plate across the inside of the C pillar, thus making it into a much stiffer box section then, the crack need only be tended to in a minor way (to waterproof and seal and/or paint). This would have to go below the damaged area to basically transfer force around it. It would be good to see what it looks like in that area from the inside. Doesn't someone have a badly damaged 80 they're parting out?

DougM

 

[Darwood]

was your vehicle repainted, darwood?

i don't even want to check on my 80s --

e

Hi Eric,

parts of my truck have been repainted (like the front clip and the roof), however I'm pretty sure the C pillars haven't. Kinda looks like it though from the pics.

 

[rgsiii]

Doug,

If I understand you correctly, some modifications could change the vibrations in ways that could improve the situation or worsen it. How would you go about determining the good from the bad? Do methods exist for determinig vehicular body flex and could it give an idea of where to position loads to minimise it?

 

[cruiserdan]

You would probably need the "smart ass" ( )suspension engineer that Doug knows to analyze it.

I sat "smart ass" because his butt is a highly trained sensor that can tell where vibrations originate from and what they mean, no joke.

 

[Jerome3]

so went out to move the cruiser after reading this thread earlier and that 95 and up myth is just that. ive got this crap on both sides of my 96 so where do we all go from here. how big of a problem is this and how hard is it to prevent further cracking?

 

[rgsiii]

You would probably need the "smart ass" ( )suspension engineer that Doug knows to analyze it.

I sat "smart ass" because his butt is a highly trained sensor that can tell where vibrations originate from and what they mean, no joke.

I used to think a smart ass was a highly trained

 

[LandCruiserPhil]

Checked out the area closely and no evidence of damage so far. But I’m guilty of all the bad things that Doug listed except a roof rack.

 

[cruiserdan]

How many miles?