4X4 Rides Big Time Bad

[mhagie]

For some reason my 4X4 rides super terrible it will all but bounce you out of the cab.
Haven't hit my head on the headliner yet but it feels like I could.
Front springs are new replacement 3 leaf units,rear are new 6 leaf units.
It started life as a HD 1/2T w/snow plow goodies.
I love the truck but I hate to drive it cause it is just toooo rough, especially on concrete pavement, blacktop is a bunch better.
I have enough money in this thing to choke a horse but I find no pleasure in driving it.
Put it together 2 years ago but only have 500 miles on it.
It also has a set of Dick Capek shocks, I don't know if they are part of the problem or not.
Any thoughts are welcome here as I am not sure what to do next.
Merle

[dieseldummy]

Merle,
I can't recall what year your basic frame/running gear is, maybe you could enlighten the more forgetful such as myself. If it is the '75-77 I think it has something to do with the rear spring pack bottom overload. My father has a '76 and an '86. The '76 is a heavy half with a hefty spring pack in the rear, the '86 is a heavy 3/4 ton with an even bigger spring pack in the rear. The only difference in the two is that the bottom overload leaf on the '86 normally rides 1"-1 1/2" while the '76 is almost in contact the whole time. It takes quite a load to make the overload come in contact with the rest of the pack on the '86, but as a result it doesn't come in contact at all during normal hiway driving. If ya take a look at your rear springs and the bottom leaf is almost touching then I would hazard a guess that is your problem.

Justin

[mhagie]

Basic running gear is a 75, and you are correct the o/load on mine in in contact all but the last 5" at the tips.
Then the difference must be in the arch in the 86?
thats the only thing that can raise the spring off the contact area that comes to mind.
I wonder about the front springs as well,when I installed the diesel engine I measured the height from no engine to height w/6.5 an it only dropped a tad over 1".
The spring pack right now sits with a slight negative arch.The donor Blazer that I used to convert mine had only 2 front springs and they had a huge negative arch.
Could this be a contributer also?
Merle

[dieseldummy]

How much negative are are we talking about here? I've seen both 2 and 3 pack springs in the fron and they usually have quite a bit of negative arch. Have you checked to make sure that the hangers/shackles don't get hung up somewhere along the path of travel? I'm going to be over at my dads later today, I'll try to get some pictures of the things I'm talking about. Might make it easier for the word impaired(me) to describe things easier.

Justin

[NH2112]

My experience is that most people overtighten the spring shackle and hanger bolts. This prevents the spring from being able to rotate in the shackle or hanger, and the shackle or hanger in the frame, and causes a rough ride.

[mhagie]

Thanks Phil I will definitely check the bolts.
Merle

[K10ANDY]

it is the negative arch . think about it , an arched spring just flattens out and gets longer when you hit a bump . The neg arch one will just try to get shorter and it is fighting itself , also the sway bar is probably binding has something to do with it . what I would do is get a lift as short as possible ,like 2" and the OffRoadDesign sway bar disconnects and and greasable shackles and try that . smile.gif -Andy

http://offroaddesign.com/catalog/swaybarkit.htm


http://offroaddesign.com/catalog/hdshackles.htm

[HammerWerf]

Merle,

When I bought my 84 pk, I remember reading that Chevy had lengthened the rear leafs, to somewhere around 56 inches Eyehole to eyehole. They were crowing about the smoother ride this gave. The botton helper I have matches the description from DD. The spring pack I have has 8 leafs and the helper. Let me crawl under there and get some measurements and confirm. Mine has always rode smooth. Had an 84 subruban 4X4 with a 3 inch lift from the previous owner, front was a bit stiff ( new springs for the lift), but the rear rode well (no one complained about ride quality).

My 83 CC duallie rides quite smooth. And you've seen the helpers on that one.

HammerWerf

[dieseldummy]

Sorry, I never got any pics or measurments. Was sick all weekend. I drove both the '76 and '86 today and tried to identify what was different between the two. I think HW is onto something about longer springs in the rear, I also think that the arch is a little bit different as well. I forgot to count the front leaves, but I'm pretty sure both only have the 2 leaf negative arch setup. The '86 sets up higher in the rear for sure, ironicly it has almost 200K on the ticker and has hauled bigger loads for more of its life...

[opto]

Regardijng the length of the leafsprings, have a look here

http://www.oliverdiesel.com/products/tuffcountry.htm

[mhagie]

Already checked it out, my 75 frame no got the holes, dam the luck anyhow.
Merle

[Dieselboy]

One thing that dramatically improved my truck's ride was a set of Bilsteins. The mono-tube gas charged shocks were ten times better than the Rancho dual-tube hydraulic shocks I had been running for the past few years.

It's still no Cadillac with 7" of lift and 37" tires, but it's noticably better - all from a shock change. Interestingly, the Bilsteins were cheaper than the Ranchos.

[Hansh]

Check your shackle bolts. Make sure they are not too tight.

[HammerWerf]

Merle,

Measured the rear springs on my '84. they are 56" bolt to bolt. Spring pack only has 7 leafs with 1 helper on the bottom.

HammerWerf

[84 Convert]

Just wondering where did you get your new springs and were there any load ratings for them? My K30 rides MUCH better than the K2500. However, the springs in the 2500 from a very heavy duty application (9 thick leaves, no overload in the rear). Both trucks have three leaves in the front, the 2500 has a little positive arch which helps when the front hits a BIG bump as it doesn't bottom out like the k30 which has quite a bit of negative arch...then comes the rear that's when you think youre gonna dent the roof in the 2500 while the 30 sails over like it was nothing. The springs in the 2500 are from a '78 while the K30 has stock '84 springs. 2500...52" K30 56". You might try swapping out the rear springs for some out of an '82ish 1/2T if the bolts are not the problem. Is there a definite difference between the front and rear? or are they both rough? In my 2500 there is and I'm sure it is the springs in the rear.

Hope this helps.

Gregg

[mhagie]

Checked the bolts and yep too tight I had them breaker bar tight, loosened them up till I can rotate bolt with wrench,next time out will see if any change.
Wish 56" springs were an option but as I would have to redrill frame to relocate rear hangers it is easy to lose ambition to do so.
So far it appears best option is to change to a 2" lift kit softride style front and rear spring kit to get the rear off the bottom overload and the front to a positive arch.
Merle