Confused!!! My right bedside is...

[BIG CHEVY 3600]

1/2 inch lower than the left side. It seems to the frame that is the trouble not the bed. I first measured at the top of the tailgate then the end of the frame rails, axles and the bottom of the fuel cell.
It's a TCI spring kit back there. Will I need to shim the right side up or is there something I'm missing?


http://s729.photobucket.com/albums/w...rent=TILT1.jpg

[mr48chev]

If you measure from the frame to the floor on all four corners do the front measurements side to side match and do the rear measurements side to match?

Is the measurement from the front of the box to the style line on the cab the same on each side?
A lot of these trucks that still run the stock suspension lean to the left simply because they only had one person in them for years on end and many many miles. A lot of others have frames that are tweaked because the previous owners hauled super heavy loads in them and twisted the frames or they sat for years in a manner that twisted the frame into a permanent set.

I cut the first frame I built for the 48 up because I had welded in a twist in the rear of the frame when I did extensive suspension mods. It looked a lot like yours from the back in that it was off on one side.

Yours won't be that drastic but you need to figure just where the lopsidedness is coming from before you can attack it. You may be able to do something with the suspension such as swap springs side to side or you may have to take it to a frame shop or you might just have to put a new bed mounting kit in along with a shim or two.

[OrrieG]

I would absolutely make sure the frame and your suspension is correct and not tweaked. If it is it will show up when you start driving it. Shimming the bed will make it look right but I suspect the bent frame will induce a little rear bump steer. I see trucks all the time with bent frames driving down the road looking like an old coon hound with the driver doing a perpetural left turn to keep them going straight.

[BIG CHEVY 3600]

I agree! Doing some measurements I have found:
Frame to floor:
center right 12 3/16" to floor Down 1/2"
center left 12 11/16" to floor

rear right 15 3/8" to floor Down 1/2"
rear left 15 7/8" to floor

Right front bed to style-line is 1/8" lower than right side

Front middle spring eye: left 11 1/2" to floor
right 11 1/4" to floor lower 1/4"
Rear middle spring eye: left 12 1/16" to floor
right 11 3/4 lower 5/16"

Any ideas on this???

[OrrieG]

I would look very close at the frame rails just in front of the point it is only 1/8" difference. Either the right is bent down or the left bent up. You should see a slight buckle in the top of bottom flange of the frame. What happened? Could be rust weakening the frame at a cross member. could have had a heavy load dropped into one side of the bed. Could have been driven over a ditch or object with a load in the bed. Could have had the frame jacked to change a tire or get out of a ditch. You are probably going to have to pull the bed to get it back in place. A good old time frame alignment shop should be able to do it assuming you did not box the heck out of it. Think of that if you did box or weld on the frame that might have created a weak point or pulled the frame. Of you can secure the good side you might be able to jack up the lower side and see if anythings moves. My right front frame extension was tweaked a little bit and I used the same technique to level out my bumper when I first got my truck.

Also, looking at the old chevy spec manual I found out that the cross member connection that has a lower brace to the bottom of the frame at the end is called an "Alligator Jaw Attachment", says so right in the GM Manual!

[tmoble]

it was sitting with the weight on the wheels when you measured that? I'd guess it's an issue with the rear springs or shackles. Even wheels and tires can affect that.

[Coupeguy2001]

you can put a shim between the spring and the axle

[BIG CHEVY 3600]

Originally Posted by Coupeguy2001

you can put a shim between the spring and the axle

The springs are under the axles. Wouldn't I need to shim at the spring eyes?

[BIG CHEVY 3600]

Originally Posted by tmoble

it was sitting with the weight on the wheels when you measured that? I'd guess it's an issue with the rear springs or shackles. Even wheels and tires can affect that.

Yeah sitting on tires. I measured the distance from the center of the axles to the floor and it was the same both sides. I guess the tires are not the issue.

[tmoble]

measure the distance between the springs and the frame. or the top of the axle and the frame.

[Coupeguy2001]

If the axle is flipped, you will probably end up adding longer shackles to the high side for a cheap fix..... however,
Usually, if the frame is straight, there is a problem with the spring.
If the spring has a problem, you might try getting a matched pair, or taking the truck to a spring shop, and they can re-arch the one spring to make it sit level.
You need to determine that the frame is indeed straight.
There is a place in Phoenix that does this, so I woud imagine that in big D there would be a couple places that can get it done for you.

Usually, if they can determine that the frame is straight, they would re-arch both. That way, you can tell them what you want your ride height is that you want, and they know by the weight how far to re-arch. I had this done on a '57 T bird, and it came out great.

When I bought an 89 suburban way back when, I noticed that the body had shims where it bolted to the frame, and a small one on that side spring. When I took it back to the dealer for warranty work, the service writer explained that with thousands of springs being manufacturered for each model year, no two springs were exactly alike, and that different vehicles showed signs of spring mismatch even though each spring was not defective, the unequal spring height sometimes caused doors to mis-align. They added different shims to adjust the body/frame assembly.

My 86 corvette has bolts that hold up each side of the car. The usual mod that everybody does is to add longer bolts to the fiberglass springs to drop them down. When I changed my spring bolts, I noticed that tightening them the same made the right hand side about 3/8" low. Upon some research, I found out that some springs were unequal even from side to side. So the fix for that was to adjust the car with a yardstick to the height desired, and then go have the rear end aligned.

How does that help you?
It may be that one spring was arched poorly, and may need adjusting.

[paintman]

Any updates on this problem? I am curious because I have the same problem with my 46.

[BIG CHEVY 3600]

Not yet, I've put it on the back burner while I finish up with 15 or 20 other little projects.

[mknittle]

is the floor level and flat

[BIG CHEVY 3600]

No it's about one inch lower on the right side.