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Old 07-01-2011, 11:09 PM   #1
KMK454
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Diagnosing Suspension Sag - Help Please

I noticed that my truck has developed a sag towards the driver's side. It seems to be even across the front left and rear left tire. I'd like to diagnose it this weekend and get working on a solution.

Aside from checking air pressures, what are some good places to look at for diagnosing the problem? The rear leaf spring does appear to be straightening out a bit. The shocks are ancient and the springs are original to the vehicle. All bushings are also at least 15 years old.

My gut reaction is to just buy new springs, shocks, and get a "rebuild kit" for all of the rubber bits... any ideas? (and those replacement parts need to leave it at a stock ride height, sorry ) Are the LMC springs and KYB shocks worthwhile?

Anbody use this kit for the rubber pieces?
http://www.performancesuspension.com...oducts_id=5829

Thanks!
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Old 07-01-2011, 11:28 PM   #2
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Re: Diagnosing Suspension Sag - Help Please

Here's some pics of what i found. The springs were mush at best when these trucks were new. I ended up taking three spring packs appart and mix and matcching the best arches and doubleing up on others. I now have usually less than a 1/4" difference at the fenders when measured. The spring pack I bulit sets higher than with a regular flip kitted truck. I'm at about 4.5" axle to frame for travel (Bump stop removed). I'm thinking I could easly go doen another 1/5" by cutting an overload spring and mounting it on top of the spring pack.

I also replaced the front springs with new stock Moog springs. Original set were cut and I didn't care for the outcome. they seemed like mush too.
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Old 07-01-2011, 11:30 PM   #3
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Re: Diagnosing Suspension Sag - Help Please

Sure do wish I could photo chop that dent out of my truck
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Old 07-02-2011, 01:29 AM   #4
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Re: Diagnosing Suspension Sag - Help Please

I have the same issue with my truck too but the drivers side is higher than the passenger. All I can think of is to get new front springs and see what I can come up with for the rear?
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Old 07-02-2011, 09:09 AM   #5
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Re: Diagnosing Suspension Sag - Help Please

1LowToy,

Those springs look good; mine definitely don't look that good. I agree that what the truck currently has feels mushy at best. No doubt my dead shocks contribue to that some on the rebound, but the springs are mush. Tires make a big difference in feel, though, and I have those whitewall donuts on there. It's a shame given how good and tight the steering boxes are on these trucks.

Looks like I'll just replace all the parts that look suspect in the suspension and see what happens... springs/shocks/bushings.
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Old 07-02-2011, 09:28 AM   #6
njlimbaugh
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Re: Diagnosing Suspension Sag - Help Please

Shock condition has nothing to do with ride height. You can throw them away and the truck won't get any lower. First, be certain that what you're seeing isn't an optical illusion caused by sagging body mounts, bed mounts etc. My 74 was sagging on the right side but I corrected it with new mounts on the cab and bed. If the mounts are sound then the springs are shot. One last possibility is that the frame is bent in which case nothing you do with the suspension will correct the problem.
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Old 07-02-2011, 12:06 PM   #7
88Jimmy4x4
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Re: Diagnosing Suspension Sag - Help Please

check your body mounts, sometimes that rubber has deteriorated so badly makes the truck sag
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Old 07-02-2011, 04:34 PM   #8
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Re: Diagnosing Suspension Sag - Help Please

My problem is the same, my driver side is lower, about an inch then my passenger. I'm going to start from the front and work my way to the back. Gonna start by rebuilding my front suspension including brand new lowering springs (current own springs have been cut). Cab mounts after that...
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Old 07-03-2011, 10:21 AM   #9
Goldfinger
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Re: Diagnosing Suspension Sag - Help Please

PLease note that if you have a sidesaddle tank your have a more constant weight of fuel on one side. i get sag when i have a full tank.
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Old 07-03-2011, 05:06 PM   #10
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Re: Diagnosing Suspension Sag - Help Please

Quote:
Originally Posted by Goldfinger View Post
PLease note that if you have a sidesaddle tank your have a more constant weight of fuel on one side. i get sag when i have a full tank.
I do have a sidesaddle tank, but it's on the higher side, not the low side!

I took an in depth look up under the truck and there's no one component that seems to be the cause. Looks like I have no choice other than to start doing everything and see if that fixes it. D'oh!
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Old 07-03-2011, 06:43 PM   #11
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Re: Diagnosing Suspension Sag - Help Please

I jacked up one corner of the rear of the truck and the front straightened out. Then I spent the rest of the afternoon looked all over the place for my floor jack plate.

But really the back springs worked wonders for the leveling. It is a bit stiff but I wanna put some miles on it before I unspring it. I driven it around the block only a few times as I'm still tinkerin
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Old 07-03-2011, 07:19 PM   #12
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Re: Diagnosing Suspension Sag - Help Please

[QUOTE=1LowToy;4769588]I jacked up one corner of the rear of the truck and the front straightened out. Then I spent the rest of the afternoon looked all over the place for my floor jack plate. [QUOTE]


Thats funny right there, I dont care who are. LOL
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Old 07-03-2011, 07:40 PM   #13
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Re: Diagnosing Suspension Sag - Help Please

[QUOTE=1LowToy;4769588]I jacked up one corner of the rear of the truck and the front straightened out. Then I spent the rest of the afternoon looked all over the place for my floor jack plate.

That sounds like something I would do. And people wonder why it takes so long to get stuff done. I have the tools, I just can't remember where they went!!!
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