Squeaky Penguin's (Trip Reports) Build Thread

I've got 21 credits (10 week quarters so it's always hectic to get everything done) and I get up at 5am Mon-Wed for work so no late nights doing anything besides homework. I volunteer after classes on Mon and Wed so no real time then either. I sorta have weekends but since this quarter is my last I don't have time to slack off and work on the truck like usual. I'm really hoping nothing breaks this quarter because I'll just have to take the bus or the bike if it does.

 

My truck bounced all over the place on concrete roads. Especially at 65mph. Best bet was to slow down a bit. There's none up here so I haven't dealt with it in a while.


I think it's a wheelbase issue more than anything. Just lines up right with the cuts in the concrete. Don't know that shocks will fix it.

 

Valving won't help. Simple as that. Shocks can't control the frame flex between the cab and box.

What you are experiencing is common with pickups that have a load on the very rear. I tried to go down this road before and was given utter bullshit for reasons why.
Lots of Jeeps, Scouts, Blazers, Bronco's, etc out there with swing-outs and bigger tires than we have and they don't have that problem at all. None of mine ever had that problem, I've owned a few Scouts and Jeeps and had friends with the other bobtails listed. I suppose we could add 4runners and Pathfinders to that list too as they don't exhibit that problem either
Why? Because full body on frame. Not cab and box with the frame flexing in the middle.
When you go to box that frame, take it all the way to where the factory boxing begins/ends. Otherwise that frame is still going to flex. To say that it only flexes in the middle is retarded as the box is bolted on either end of that supposed flex location and adds quite a bit of strength to the frame itself.
When the frames rust in two, they don't split in the middle of the box, they split between the cab and box, where all the flexing has been taking place.

 

So the short term solution is to remove some weight from the rear and live with it. Long term solution is to box in the frame and stiffen it up.

Si?

 

Next time I drive 287 South of Loveland I'll report back on the harmonic bouncing. Or maybe my 6" of unboxed frame that is solidly bolted top and bottom to factory crossmember will keep flexing. Also, the front bed mount is in front of where the boxing ends. So that negates your theory on cab to bed transition and the bed stiffening things.



We really need to conduct a test and drive the section of road, then take of the rear bumper and drive it again. I bet it would be worse without the rear bumper. I think the problem stems from the stiffer suspension we are adding, not the frame. If the suspension was setup to handle the concrete roads, it would not perform how we want offroad. Pick one. All the vehicles you mentioned have a shorter wheelbase than our trucks, do they not?

 

Correct.
Look at it this way..
Did you have the problem before the swingout? I'm going to guess, no. mainly because I didn't have the problem either.
What I did have was a much smaller spare tire at first, the bounce was really minimal.
When I went to the bigger spare, it got way worse.
\The shocks can only control the movement of the axle under the frame. They can't control frame flex.
These trucks have a known weak frame in the rear, adding any weight to it (hanging offf the end) will cause it to cantilever at some point and get the shakes.

On a side note, through the winter, I had about 250 pounds of sand bags in the back. As an experiment, I shoved them clear to the front of the cab. It actually reduced the frame flex/bobbing on those concrete roads. I've since removed the sand with the warm weather and it has come back.

 

You're wrong but keep hanging onto that theory.
You're saying the frame is flexing under the bed. I say it can't as the bed holds it in check.
If it's bent, it's because it bottomed out in stock form.
You missed the worst part of the frame flex imo. Just because the manufacturer of the plates decided that was a good place to stop?

 

There is space, in the frame, between the rear most cab mount and the front most bed mount. This is where the flex is happening.
Try to explain to me how the front of my canopy hits the back of my cab when the frame isn't flexing right in that location? So apparently what is happening is the entire frame and box are buckling in the middle and undulating towards the front? Bullshit.

 

I don't have a horse in this race but I will say the bed is just some thin sheet metal that bolts in a couple locations that are on levers(stilts) so I'd wager that if I can flex it with my bare hands the frame can probably flex it too.

 

So you're saying the frame is flexing where it's boxed?



Note where the factory boxing ends and the front bed mount is.

Really, I think boxing the frame was unnecessary, just thought it couldn't hurt while I had everything apart. To box the section I didn't and change the mounting of the factory crossmember would be a ton of work.

 

Oh goodie, look what I started

 

I give up. It's like herding cats in here.
I would have boxed in that remaining portion. Since @Speedytech7 thinks that the bed flexes as well, then it would only make sense to box the whole thing in.

 

Our frames are weak even in the boxed sections, it flexes no matter what you do. Such is the nature of thin steel. I don't think boxing the rear is necessary at all, just the plates plus his custom crossmember are enough. But it'll still flex, no biggie really

 

This.

While yes our frame flex a lot. I have yet to experience this crazy bucking in Frankenstein which, lets be honest, if fatter and heavier then any of your rigs. And my swing out is much heavier with a 35'' tire plus 5 gal of gas and a 20lb Co2 bottle. And i have not reinforced or boxed the rear frame..

mmm not really. Thats a wheel base thing. All of those vehicles don't hang out the weight as far behind the rear axle as we do. Period.

Oh can't be that bad! 5.29s!! okay yea i know..

Moving weight might help. but at this point, you need to decided how to setup the truck and start tweaking the rest to make it work that way. So if you want the swing out, get to redoing the suspension. haha Classic change one thing...means you have to fix 3 others.

Yea, idk man. I didn't have normal homework like you though. I had audio projects. Which didn't have the same time load..which was worse really in a lot of ways..I'll admit my college experience was not the normal one.

 

Bullshit. Frame lengths are within 12". Full body on frame reduces frame flex. Period. Your just being stubborn to think otherwise. My Scout is only 8" shorter in wheelbase and has a 37" tire hanging off the back.

 

yea by how far from the rear axle to the swing out on the Scout vs on a tacoma??? Thats my point.

12'' is a LOT of leverage man...

 

I said 8 inches of extra wheel base on the Taco, compared to my Scout. Within 12" of extra overall frame.
And you just contradicted your own point about what what you said earlier....It's the hanging over the back, right? shocks can't control the last bit of frame behind the shackles. They can't control the bit of frame in front of the hanger either.


And that extra little bit of leverage hanging over the back is causing the flex on an already weak frame, which was already mentioned by @Speedytech7 , but hey, it's already weak, why bother to stiffen it up right? I can't see how making something less limp is better when trying to combat the shakes.

 

But 10 minutes prior you were saying the bed holds it in check?

What does it even matter that our trucks bounce around on the concrete roads other than an annoyance? I'll gladly take my swing out over a smooth ride the occasional time I'm on a road like that, if that is even where the problem is caused.

 

I haven't changed my opinion at all I know I'm right. It's an automotive fact. Full body on frame stops or greatly lessens frame flex. Sure, when you get to limo length, that may change.
I'm just done arguing with the brain trust. Carry on.

 

This discussion is a big reason why I'm not going with a swing out tire carrier for the spare.