Weak!!

[yoncey]

Wondering if anyone one else has this same problem and if this typical for K5's.

I hitched on my 21' enclosed trailer (empty) onto my K5 for the first time, just to move it around on my property & relocate it. The springs held up with no sag...however, due to the weight...my frame or body moved because I could not open my doors!!!!! HUH!!!! Once I realized that, I quickly removed the load and the doors went back to normal where I can open and shut them with no problem. Ever since this happened I have noticed while driving around in my K5, when ever I hit a bump etc...the gap between the door and the rear bed moves???? Is it normal for blazers to have this much play?
Having the hard top would probably make it more solid and since I am running topless its more flexible maybe??? it drives me nuts now that I have noticed this....

Once again...is this normal for K5's to have that much play? thanks in advance for any responses....

[ugly]

My 72 bed and door move a lot when the top is off. I was shown a brass plate that goes on the door and body to reduce the movement.
http://67-72chevytrucks.com/vboard/s...d.php?t=273729

I also have a full family roll cage and you can see the windshield move compared to the cage when you hit a bump. All of that movement is reduced when the top is on.

When I go wheeling and the truck is twisted at all, you can't open the doors.

[mtully79]

Great thread, what are the plates called so I can get some ordered up?

[jeffahart]

This is odd to me.
I have had just about every type of pickup. I'm and old mason. I've loaded most of them if not all till they're nearly doing a wheelie at some point or another during owning them. Cannot tell you how many times I've driven bottomed to axles. But I have never had a truck that I could not open the doors when overloaded.

I don't think it's normal. Maybe I've just gotten lucky over the years but I don't thinks so. I usually ain't lucky.

[wauto]

Actually the Ford unibody truck of the early sixties was the same way...looked cool till ya put a load on her. Then the doors wouldn't open.

[jeffahart]

Oh, good point. Maybe I jumped the gun being it's a blazer. But, I have to say, it would really but me too.

[ugly]

Here are the brass plates

$47.00 Door alignment wedge
http://www.opgi.com/cutlass/1969/doo...inges/CH24776/

[GMC-YA68]

I'm still learning but I thought this is why people box in the frame?

[mcmlxix]

I see three issues that contribute to body flex...
1. The fame is a like weight C channel for a 1/2 ton truck. One ton (and maybe 3/4 ton) trucks uses a thicker material on the chassis.
2. Old worn rubber body mounts and weak non torqued body bolts can result in flex.
3. Nonstructural body. No roof means lots of flex. A full cage bolted to the body will help, but a cage that’s part of the frame will increase the rigidity exponentially

the (best nut non-original) fix:
Box the frame, add some crossmembers
New poly body mounts and new bolts
Build a cage that ties the frame into a 3D shape rather then just 2D.

[1972K20]

Where's the hitch mounted up? I'm curious as to how pulling a trailer affects the body and doors. All the weight should be on the frame/springs/axles.

[Blazerowner]

I was thinking the same thing how does a load on the frame affect the body that much?

[cleszkie]

I've had the same results when towing. Not unusual for these early Blazers. The trailer tongue weight pushes down on the frame behind the rear axle causing the frame to bow up infront of the rear axle. This causes the door opennings to spread open a bit. Balancing the ltrailer load to reduce the tongue weight will help the issue.

[imjeff]

You can't take the flex out of the frame and you shouldn't. Pickups have seperate boxes for a reason. I've never had a pickup that wouldn't twist until the bed hits the cab...it's normal. If you stiffen the frame to zero movement you will break the next weakest component and have a truck that weighs six tons.

[87Skier]

I agree that's why trucks have separate cab and beds. I can't count how many times going woodcutting we have loaded the truck then carefully pulled it out and every time we can watch the gap and alignment change.

Good to know about the body flex though. I've been thinking about towing my boat behind mine. Might have to rethink that.

[Blazerowner]

Would boxing the frame help with the flex? I personally have never towed with mine but just installed a hitch. I don't plan on towing more than 3-4000 pounds. I wonder if I will have the same issue.

[imjeff]

Boxing the frame adds rigidity, which sounds great...to a point. Once an assembly, especially a large one, is too rigid, it starts cracking and breaking under stress. Plus adding heat to the length of your frame will change the characteristics of the steel, but people do it. I do for specific places where strength is needed, but not to stiffen an entire truck.