Our "heavy duty" suspensions (height measurements)

[Mike H.]

The Chevy and GMC advertising for these trucks always mentions something about their "heavy duty" or "increased capacity" suspensions. Yeah right. Has anybody else noticed changes and settling in their truck?



A few days after I bought mine last summer, I noticed the DRIVER side appeared to sit lower than the passenger. A quick check of the front wheels with a tape measure indicated my driver side sat just under 1" lower than the passenger side. I always measure from a common point on the wheel (edge of the center cap) up to the lower edge of the fender so that differences in tire pressure are not a factor. I called the GMC service department, who replied that some variation is normal, and they would not look at it until it had at least 3,000 miles on it to "settle in".



At 3,000 miles it was still noticable (3/4"). I decided to adjust it myself instead of take it to the dealer and leave it for a day, only to probably hear it was "within spec". I cranked the driver side up level with the passenger side, then gave each side an extra 1/2" or so for good measure.



Now this past weekend (15,000 miles now) I decided to crank them up more. A quick check of the tape showed that now my PASSENGER side was lower than the driver by 1/2". Nice uneven "heavy duty" settling. I now have the passenger side t-bar adjustment bolt cranked all the way in to level it. The driver side still has about 3 threads showing. I doubt the bolts are different length. I guess if the driver side sags any more, I can still crank it back up a little to fix it.



Now lets talk rear springs. The truck was very nearly level when I bought it. After adjusting the t-bars at 3,000 miles, it was level at best. Now it is 1.25" LOWER at the back wheels than the front. I have not had it off-road (a few gravel roads don't count), I do not tow with it, and have only hauled a heavy load about 5 times. Even then it was fairly distributed and around 500-600 lbs.



Anybody else feeling like their rear end is sagging more than usual? (Not talking about overeating!) I'm probably going to do the rear springs-over-axle swap (5") just to take out the sag and give it a little "rake" like the new HD full size line. Anybody else prefer a higher rear stance? I've noticed Dodge's full size line has at least 4" to 5" higher rear, and a few of the Fords too. Your thoughts and opinions will be appreciated. Thanks.

[HenryJ]

I hear what you are saying and agree. I've been told that variances of up to 1" are acceptable , not to me though!

The rear of mine needs to be raised a bit too. I plan to visit a local "Spring" shop and get mine raised a little over an inch in the rear.

I had considered using an off the shelf add-a-leaf, but the concerns over losing ride characteristics and articulation have not been resolved yet.

The guy at Boise spring works is willing to put together a kit and I plan to see what he can do for a GP, if anyone is interested?

It would be all the parts needed to take one leaf out and replace it with three thinner leaves.

I'll get motivated and get more details, soon I hope.

[Conman]

I noticed when I load it up some, my lights are pointing north and people think I'm running with my high beams on. I'm not sure what I'm going to do at this point. The Crew is going to the dealer on Thursday for inspection and oil change and I was planning on them looking at it for the squeaky rear suspension. I'm going to ask them to see if it's leaning as well.



Con

[Justin]

honestly, My truck at 33,000 miles still has the rear end higher than the front by 1/2"-1". I have adone alot of hauling



1) Bobcat attatchments (600lb jackhammer, forks, york rakes )..all in the 500 lb. category



2) I also put it to the test transporting cement curb (biggest is 6' sometimes weighing at 700lbs.



after I had the BL installed and before the 31" BFG, my front driver side was lower by 3/4". I ONLY jacked up that side to even it out.. Maybe by raising both sides of the front of ur truck, it may appear to look lower in the back now

[NTXCrew]

I thought the Heavy Duty was referring to an increase in payload capacity.

I got this from Chevy's S-10 site:



Z85 Increased Capacity Suspension Package



Designed for loading and hauling, this suspension includes multileaf rear springs,

a rugged independent front suspension, 32mm twin-tube shock absorbers and

29mm front stabilizer bar.



It's optional on the base S-10 and standard on LS, Crew Cab, and ZR5. It's not available for the Extreme or ZR2.

[Mike H.]

honestly, My truck at 33,000 miles still has the rear end higher than the front by 1/2"-1". I have adone alot of hauling



1) Bobcat attatchments (600lb jackhammer, forks, york rakes )..all in the 500 lb. category



2) I also put it to the test transporting cement curb (biggest is 6' sometimes weighing at 700lbs.



after I had the BL installed and before the 31" BFG, my front driver side was lower by 3/4". I ONLY jacked up that side to even it out.. Maybe by raising both sides of the front of ur truck, it may appear to look lower in the back now

Yeah, except I've been actually taking measurements. At 3,000 miles, it was about level after the t-bar crank and front "leveling" side to side. Now, 12,000 miles later, it is about 1" lower at the back wheels than the front. All I did to the front last weekend was to re-level the passenger side only. So from 3,000 to 15,000 miles I have lost about 1" in the rear.



Here are my current measurements, using a 24" steel carpenter's square, from the lip of the wheel well to dead center of my wheel center cap (dead center of the M in GMC). Tire pressure fluctuation is not an issue if not measuring from the ground:



Front driver - 19-3/4"

Front passenger - 19-7/8"

Rear driver - 18-5/8"

Rear passenger - 18-5/8"



What do you guy's get? I have no body lift. Thanks.

[Mike H.]

Anybody take any measurements? Is my truck abnormally high in the front or too low in the rear? Thanks.

[Dragonmaster]

High in the front. They come 1" lower in the front from the factory for a reason. After you break it in it sits about level. If youhadn't done the t-bar crank it would probably only be about a 1/4" lower in the front.

[Mike H.]

The rear of mine needs to be raised a bit too. I plan to visit a local "Spring" shop and get mine raised a little over an inch in the rear.

I had considered using an off the shelf add-a-leaf, but the concerns over losing ride characteristics and articulation have not been resolved yet.

The guy at Boise spring works is willing to put together a kit and I plan to see what he can do for a GP, if anyone is interested?

It would be all the parts needed to take one leaf out and replace it with three thinner leaves.

I'll get motivated and get more details, soon I hope.

How much height difference do you have between your front and rear wheels? I'd be interested in a rear spring kit. I'd really like something to raise the rear about 3" from current height. I could do an add-a-leaf with a shackle kit, but I'm not real fond of shackle lifts. I'd prefer a spring kit only.

[Justin]

1/4-1/2" lower in front sounds right



fr = 21"

fl = 21 1/8"



rr = 21 1/2"

4l = 21 1/2"

[Mike H.]

1/4-1/2" lower in front sounds right

fr = 21"

fl = 21 1/8"

rr = 21 1/2"

4l = 21 1/2"

Thanks Justin, I really appreciate it. I'd like to compare to more trucks to see where I'm at, and if my rear is abnormally low. Subtracting 2" for your body lift, looks like my suspension is set 3/4" higher than you in the front, and 7/8" LOWER than you in the rear.



Can anybody else give me some numbers for comparison? I'd appreciate it.

[HenryJ]

2" body lift and Bushwacker flares-

FL-21 1/4"

FR-20 3/4"

RR-20 3/4"

RL-21 1/4"

[Mike H.]

Thanks. Keep 'em coming. I'm keeping a running average. I'll subtract 2" for the BL. So far (after only you two guys), average front is 19.03", and average rear is 19.25".

[Justin]

Mike, I think that because you have your torsion bars fully cranked, it may look too high in the front....I only touched the drivers side to level it out. If it is lower than everyone elses, think about buying shackles..I bet it would level the truck out

[HenryJ]

After Boise Spring Works install:

FL= 21 3/8"

FR= 21"

RR= 22 3/4"

RL= 23 1/4"

[Mike H.]

After Boise Spring Works install:

FL= 21 3/8"

FR= 21"

RR= 22 3/4"

RL= 23 1/4"

TERRIFIC. Subtracting 2" for your body lift, you are now about 2.5" taller than me in the rear. By your measurements you got exactly 2" from that spring lift. I just responded to your GP thread. Put me down for a set. If the GP does not pan-out, please give me the contact info and I'll buy a set by myself. That is just what I need. Thanks.

[Mike H.]

rr = 21 1/2"

4l = 21 1/2"

Taking off 2" for your BL, you are just shy of 1" taller than me in the rear, and you've been towing and hauling. Why has mine sagged so much, considering I seldom haul and never tow anything? I will be correcting it VERY soon.

[Mike H.]

I finally took care of my sagging rear springs. My rear had sagged about 1" since new.

I installed the Trailmaster 3" add-a-leaf kit (#R1537) this morning. The kit cost me $50 at the local truck/speed shop. It is the same part number Trailmaster also lists as their 3" kit for Nissans, Toyotas, and as 2" on the older Landrover.

The spring is 24" long and 2-1/4" wide. (Our stock springs are 2-1/2" wide.) It is slightly thicker than our 3 regular leaves, but is tapered toward the ends. The ends are actually slightly thinner than the stock leaves.

On my truck, it gave me a 2-3/8" lift. I removed the flat overload spring and installed the Trailmaster leaf in its place as they recommended. It took about 4 hours. Much of that time was spent fabbing a couple of spring clips. I drilled and countersunk the leaf ends and used a grade 5 flat head bolt and locknut to attach the clips. I also bathed everything in silicone lubricant before putting the springs back together.

I drove it about 30 miles after the install to let everything settle in. Ride is a little firmer and noticable higher. Here are my current measurements, from the lip of the wheel well to dead center of my wheel center cap (dead center of the M in GMC):

Front driver - 20" (I tweaked this one a little)
Front passenger - 20-1/8"
Rear driver - 21"
Rear passenger - 21-1/8"

(Note: These are BEFORE my bodylift.)

I'm still shooting for the back to be 2" to 2.5" higher than the front, so next is a small shackle lift.

[HenryJ]

Don't forget that by raising the rear , you alter the caster angle of the front.

Once you get everything the way you want it make a visit to you local alignment shop to check the front end.

Most places around here won't charge anything if it checks out OK and they don't need to make any adjustments.

[a2b]

I thought the Heavy Duty was referring to an increase in payload capacity.

I got this from Chevy's S-10 site:



Z85 Increased Capacity Suspension Package



32mm twin-tube shock absorbers and...

this is the funnies quote of the thread

[HenryJ]

After Boise Spring Works install:

FL= 21 3/8"

FR= 21"

RR= 22 3/4"

RL= 23 1/4"

October , after lots of offroading :
FL = 21.5
FR = 21.25
RR = 22.25
RL = 22.5