The Rake Discussion (Why go with Z71 springs)

[HARDTRAILZ]

Yes. New BDS purchases (either hydraulic or gas pressurized) would get the upgraded cylinder. Sized for being able to handle the Tahoe Z71 springs that are now mandatory kit.

What kit and why mandatory? If you dont haul weight, what benefit is there other than a hideous loking rake on your truck?

[Philberto]

That's the point... most of us carry large loads of recovery, repair, and camping equipment, and we need the weight capacity. Also, hideous looking rake = better front visibility and improved mpg.

[HARDTRAILZ]

How does rake improve mpg?

My supplies must be lighter or I pack less because 3 or 4 days camping stuff, 100-150 lbs or so, doesnt create much drop in the rear and leaves it quite difficult for me to justify z71 springs, when with less lift, I am not nearly as quick to max out the shocks as anyone with z71 will, esp if they are stock length or z71 takeoffs.

Also doesnt the extra height hurt the COG when you pack a bunch of weight up on a roof rack that is now 3 inches higher than where it would be without the z71's.

I can fully appreciate the z-71's on a few peoples rigs that tow constantly or keep 4-500 lbs of gear in there truck all the time, but that is only a select few, so it would seem the z71 should be the exception, not the rule

[Philberto]

Rake improves mpg by improving highway aerodynamics, useful for me in southern california. Also, I know that Bill packs the kitchen sink, and I carry an estimated 400 - 500 lbs in the rear, mostly because the back of my tb is my garage toolchest. I have no room to unload it, so I just carry everything all the time. Loaded up, it makes the z71 springs perform properly IMO, and it definitely felt saggy when I had stock springs pre-lift, when loaded up. I've no regrets, and just recognize that I always need a lot of weight in the back.

[HARDTRAILZ]

Our rigs are not set up to be aerodynamic...extra lights, wide tires, roof racks, cut bumpers...so I think that argument is not so good. I have never heard of anyone lifting the rear of any 4x4 to get more aerodynamic and mpg's. I did search some and see that is does make a slight different going from level to rake, but I have an 1 inch of rake. I would love to see some proof that going from 1 inch rake to 3-4 inches rake affects the mpg. At that much rake the air is hitting the roof and roof rack firstm not sliding over the windshield over the top of the truck. It appears it might hurt mpg to over rake the truck.

Back to my first questioning...

What advantage is there to z71 springs if you do not need them to carry extra weight?

[janesy86]

I think this convo should be carried on else where, but I have to say that right now I just have the Z71 springs in. I sit level pretty much, slightly higher in the back. Still planning on throwing Marks spacer in the rear for more clearance for the gas tank...

I did get the springs mostly because at work I'll throw 300+ lbs in the rear along with my full size rear. That keeps it from sagging alot, but otherwise I'm unweighted besides the spare and I still think its got a great ride. Even better now with the BDS 5500 series shocks.

And also just so you know if you didn't, but I think you do, the Z71 springs only give 1.5" of lift give or take. And for the use unweighted I'd say for extra gas tank clearance. Not lookin for aerodynamics here..

[Gordinho80]

What kit and why mandatory? If you dont haul weight, what benefit is there other than a hideous loking rake on your truck?

Hideous rake? You call this hideous?

[HARDTRAILZ]

Mario...what does yours measure front and rear at the center of the wheels?

I was under the assumption that the z71 was 2 to 3 inches over stock. I may have been wrong. If so, I can see running the z71 without spacers, but the only z71 springs I have seen on a tb in person have all used them in conjuction with spacers and it leaves the rear enough higher that I do think it is hideous.

I want low and level and no tire rubbing/touching/brushing at all. I wish the 2 inch body lift had been enough to clear my tires, but they slightly rubbed and that is not gonna fly offroad when the truck is all bound up and it happens. I go back and forth about the z71's, but really do need some reasons as why I should since I cant find a reason they will help me.

Other than the increased weight carrying, how does the ride change? Mine is plenty stiff----read "truck-like"-- and can't see any stiffer as being an advantage. Plus I think softer springs are better on tough trails.

One of our wonderful mods will toss this dicussion elsewhere, when they get a chance. They are good like that. Most of us on the other hand are quite good at thread jacking, so we are lucky to have them clean up our messes.

[Gordinho80]

One of our wonderful mods will toss this dicussion elsewhere, when they get a chance. They are good like that. Most of us on the other hand are quite good at thread jacking, so we are lucky to have them clean up our messes.

Ask and you shall receive...

[janesy86]

Dang, did my whole post above get skipped?

Like I said 1.5" of lift the Z71 springs give. I don't think they are too stiff, actually ride really nice, and I am mostly unweighted in the rear. But its nice having them there when I need em. Plus they are cheap.

I think the rake Mario got going is perfect. Got to get mine like that soon and I'll be happy.

[rgraboske]

What kit and why mandatory? If you dont haul weight, what benefit is there other than a hideous loking rake on your truck?

What I find interesting is when looking at the history of GM Trucks, the 2WD trucks always sat higher in the back, and the 4WD trucks always sat lower in the back. To a degree this is still true on the full size pickups, but not so much on the SUVs. I imagine there is a reason for this, whether it be fuel economy, or safety, or looks.

I happen to know the retired GM Designer who was over this studio when these vehicles were designed, so I'll be asking him the next time I see him upon his return from FL.

[fishsticks]

My rig, with .75" Rough Country spacers on top and 2" SMaxx spacer on the bottom of Z71 springs, sits 2.5" higher in the rear unloaded. I have .5" shims on top of my front lift as well.

[Philberto]

I suppose, as James has mentioned in the past, that a primary advantage is that if something gets wedged under the frame, clearance increases as it gets further back... so there is always that. Thanks for moving the thread btw... bit difficult from the phone.

[MrSmithsTB]

I suppose, as James has mentioned in the past, that a primary advantage is that if something gets wedged under the frame, clearance increases as it gets further back... so there is always that. Thanks for moving the thread btw... bit difficult from the phone.

That is the only benefit that I see to these springs over using something else instead. I achieves the rake without stacking spacers so you can get unstuck while moving forward. However, I just reinstalled my lift and I used my stock rear springs with the Z71 shocks. I have not measured yet, but there is a visible rake. Not much, but visible. There is the potential for it to sag if I load too much in the back, but that can be corrected with airbags inside the springs without having to go any higher. I like a level ride, so this works for me.

I don't know if anyone else is running the same rear setup here, but I have a feeling they will say the same thing.

[rgraboske]

Question for the lifted guys. How much is the rake? I just measured mine, unlifted with probably sagging springs, and get 8.5" from the bottom of the frame rail under the front body mount, and 9.5" under the rear body mount. This was on the right side knowing that the left side sits about 1/2" lower.

I know you all sit a lot higher, but what is the difference between these two body mounts?

[HARDTRAILZ]

Mario I looked at your build thread and it looks like you have no spacers, just z71 in the rear. I am really curious to know what that measures versus my stock springs with just spacers. If similar, I will pick up a set and try them out to find out which i like. i figure i can always resell them if i dont like them.

[MrSmithsTB]

Mario runs BDS front and rear with the Z71 springs and the MarkMC shim up front. If you don't want a rake but still want to use the Z71 springs, you can always grab a set of 1" SMAXX rear blocks and couple those with the springs for 2.5" of lift. That is an option I am considering if I don't like the rake once I eat my words and get a set.

[HARDTRAILZ]

I want what I have now 1 inch diff front to rear or less. I believe mark's spacers gave me a bout 1.5 so it should work to try just the z71 springs.

I looked and he didnt have anything listed for rear but z71 so i will go back and look again. I dont know what the bds does for rear lift. i would assume just a spacer.

[MrSmithsTB]

BDS uses a rear top mount spacer. There is about a 1.5" difference stock front to rear. So I guess the springs would work in place of the spacer. Come to think of it, bobbyblaze may have run to SMAXX 2.5" front and Z71 springs rear. He sat pretty level. I wish I could double check that, but he doesn't have a build thread from when he still had the TB.

[The Roadie]

Sorry - didn't get back to this right away. I don't care what the rake looks like or what the MPG penalty is, and I was maybe the first one to scrape frame rails a LOT on a trail I got obsessed with climbing, so I was speaking from experience and 31.5" tires when I said I like the way the truck gets unstuck if it's higher in the back.

I also overcompressed and had to discard two sets of OEM springs for taking a permanent set. Three if you count a set of fronts I had to discard. And all this in only 80K miles.

And with the cantilevered spare carrier on the back, rear spring stress is even worse than stock design, and I really never take out the full earthquake/wildfire bug-out-supply gear. The Roadiemobile is a survival tool, not just a daily driver.

I consider the Z71 springs essential also for their higher and progressive spring rate, to reduce the number of times I hit the bump stops. And to allow for a larger diameter Airlift bag for more compensation force per PSI of bag pressure.

Perhaps I overstated it, but I do tend to forget that other folks carry a lot less stuff. The springs can allow you to skip a rear spacer if all you want is a small lift, because a spacer on an OEM spring can mash it flat if you don't also add thickness to your bump stops. It's less likely to mash a Z71 spring flat.

AlekG's LIFTED Tahoe springs give 2.5" lift on a Tahoe, and 4" for us. I would have put those in except I use a WD hitch to tow my trailer 8-10 times a year, and an extra couple of inches would max out the adjustment range on my drop mount.

Anybody wanting to do a vernier adjustment, I have a couple sets of rear and one set of front 1" SMAXX spacers to sell cheap. Damn, and I know I owe you an email about some stuff, Kyle. Sorry. Political fight at work has me on edge.