Rear suspension help

[Callaway]

Hey yall,

I have an 09 Tahoe LTZ. I recently, with info from this forum, did the z55 delete.

I did bilstein 5100’s and new springs on all four corners, running the z71 (moog 81069) springs in the rear, I did new upper and lower control arms, and new end links. Essentially 100% new suspension. I LOVE the way the truck sits now. I set the 5100’s on the second notch in the front and I got a 2-3” lift out of the whole setup. It looks fantastic.

Here’s my issue— as soon as I put any weight on the hitch the rear end sags like a son of a gun. Makes the truck look like it’s squatted. Not only do I hate the way it looks, it makes the truck dive like crap. For context— I pull a little dump trailer that weight 2300 lbs empty and a cargo crawler that weighs less and this happens when the trailers are empty. The tongue weight can’t be more than 500lbs or so. Luckily I just move them around for my business so they’re empty 95% of the time I pull them, but I’d like to do something to correct the issue so it doesn’t look so dump, but mostly so the truck handles better when pulling.

Has anyone run into this? What’s the fix? Stiffer rear springs? Bags? A combo? I’m open to whatever. I love this rig.

 

[Joseph Garcia]

The rear springs for the Z55 suspension are softer than the OEM non-Z55 suspension rear springs, as the air bags on the Z55 suspension take some of the truck's weight. I don't know how your Moog 81069 springs compare to the OEM non-Z55 springs, but I would check that first, to rule out any potential spring compatibility question.

 

[Callaway]

The rear springs for the Z55 suspension are softer than the OEM non-Z55 suspension rear springs, as the air bags on the Z55 suspension take some of the truck's weight. I don't know how your Moog 81069 springs compare to the OEM non-Z55 springs, but I would check that first, to rule out any potential spring compatibility question.

The 81069 springs are the stock z71 spring for the same generation Tahoe. They’re taller and supposedly stiffer, but apparently not that stiff. Lol

 

[Dustin Jackson]

@Callaway Very interesting I haven't seen this one yet, there are some obvious solutions but it seems like you shouldn't be having this problem in the first place

 

[Callaway]

@Callaway Very interesting I haven't seen this one yet, there are some obvious solutions but it seems like you shouldn't be having this problem in the first place

That’s what I thought too! I’m hoping that some of the experienced guys around here might have some thoughts.

 

[Dustin Jackson]

@Callaway I would start looking into adding air bags like that other person mentioned in another thread to you, even if you do go with another spring air bags might be recommended regardless of which spring you use

 

[Charlie207]

That’s what I thought too! I’m hoping that some of the experienced guys around here might have some thoughts.

Firestone Coil-Rite: 4108 Rear Kit​

You can spec out stronger rear springs, but it'll wreck your ride 99% of the time, when you don't have a trailer on it.