Body Flex

[ol'blu72]

Ive been hearing a very annoying squeak and I pinpointed the cause. My body is flexing causing one of the rivets in the door jamb to contact the striker plate. It is wearing a little groove in the striker. What concerns me is the body flex, if i bounce in my truck I can see the flex by watching the door gap. The movement is maybe a quarter inch. Should I be concerned?? My fear is I will have to replace my rockers sooner rather than later.

[71swb4x4]

How are the rocker boxes? How about the bushings between the frame and the body mounts?

[ol'blu72]

My bushing are pretty shot I was going to try that first hopefully that will fix it. I dont want to jump into the rockers quite yet, after all its summertime and I want to drive!!
I do see some slight rot beginning on the rockers (starting to bubble paint), and from what ive heard that means its not going to be any better inside.
Does anyobody know how much flex is normal??

[turp mcspray]

A lot of the inner structure that you can't see (lower hinge pillars behind the rocker, lower kick panel area below the floor level, and front floor supports) are more than likely rusted away. This will drastically weaken firewall/cowl strength.

[Burt4x4]

Are your rocker boxes still inplace?
Take pics

[ol'blu72]

Originally Posted by turp mcspray

A lot of the inner structure that you can't see (lower hinge pillars behind the rocker, lower kick panel area below the floor level, and front floor supports) are more than likely rusted away. This will drastically weaken firewall/cowl strength.

See this is exactly what I didnt want to hear

Yes my rockers boxes are there, however I have the rear covers off them, but I dont think that would affect it that much.

I will shoot some Pics when I get off work. I will also check how bad the body mount rubber is in that area.

[ol'blu72]

Here are some pictures of the drivers side rocker, this is the bad side. So tell it to me straight is it gonna be major surgery or can I nurse it along for a while?[ATTACH][ATTACH][ATTACH][/ATTACH][/ATTACH][/ATTACH]

Here is the body mount, looks like its had better days.

[Burt4x4]

That's not bad at all! hahaha
I would put that rockerbox bact togeather and then buy a body mount kit from EnergySuspension and replace that old rubber. I would leave the rockers..about 10yrs from now then replace them

[1949gmc]

Originally Posted by Burt4x4

That's not bad at all! hahaha
I would put that rockerbox bact togeather and then buy a body mount kit from EnergySuspension and replace that old rubber. I would leave the rockers..about 10yrs from now then replace them

x2.... more than likely, the bottom of the A pillar and the front body mount are rusted some, but by the looks of it, not enough to cause the kind of flex you're talking about. That's a clean truck, as far as first gen K5's go. Change the body bushings and go from there.

[ol'blu72]

Man you guys are my new best friends!! I should buy you a beer!

[ol'blu72]

Ok, so now what are the pros and cons of the urethane mounts. I'm trying to keep her as stock as I can so right now I'm leaning towards rubber.

[70cst]

Originally Posted by ol'blu72

Man you guys are my new best friends!! I should buy you a beer!

I'll get you their addresses



Just kidding

[turp mcspray]

I am restoring a 72 2wd, for a customer. His rocker boxes are excellent. But due to the rust I described above, I could move the top of the windshield frame, back and forth by SEVERAL inches! I think some blazers had rusty floor supports and lower hinge pillars installed at the factory. LOL! As others have suggested, I would also start with those rotten body bushings. Since the rear rocker box covers are off, look inside them with a flashlight, to check your floor supports.

[SeventyOne]

I am going polyurethane to prevent the rubber ones from squashing out like yours. I figure the added rigidity and longevity can't hurt.

[Burt4x4]

I swtched to Poly about 17yrs ago and I have never had to mess with the mounts eversence

I learned two things about Poly.
1. Black vs. Red ~ Choose Black- Black is impregnated with polygraphite too prevent "poly squeek". Red is just for looks
2. Do not overtighten or squeese poly. It will bind and not flex. I got the mounts nice and snugg right before the poly starts too bulge. If you overtightn it just too see the mount bulge then back off the nut until it relaxes. Then I used nylon lock nuts to keep things inplace.

I remember it changing the way my rig road bigtime! Made everything feel so much more solid...well not too mention only 5 out of the 12 mounts were actually holding the body too the frame too begain with!!

Some like rubber too use in a reto project but I think poly out performs rubber in both time and function...

Anyway I need more coffee