AAL vs 3/4t Springs?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

boy&hisdogs

I'm Awesome
Joined
Mar 2, 2012
Messages
569
Reaction score
630
Location
Eastern WA
Are they perhaps from a 2500LD the OP was talking about then? Note he said those will lift the rear the same as the AAL. I believe those came with the 14 bolt with the 2500 6 lug trucks. Or they aftermarket?

I honestly don't really know what the "heavy half" is on the GMT400, but sounds like it's the same as the 2500LD? I'm always confused on those trucks, LOL.

"Heavy Half" is the 1500HD, which was a GMT800 truck. It had 8 lug axles, a 6.0, a 4l80e, and stiffer springs and a few other goodies. It was a rare option.

As for GMT400s, we have two 2500 models. We have the "light" one that was six lug and had a 7200# GVWR rating. It was essentially a half ton but with the 9.5" 14b SF rear end and stiffer springs. It still had all the 1500 front end parts, including the smaller 8.25 front diff.

We also had the heavier 2500 with a 8600# GVWR. That was an 8 lug. This came with either the 10.5" 14bFF or the 9.5" SF but with bigger brakes than the LD 2500 (13" vs 11") and the bigger 9.25" front end.

BUUUUUTTTT then there was the "F44" option for the 1500s that gave you the 9.5" 14b SF rear end out of the LD2500. People refer to this as the "heavy half" sometimes.
 

boy&hisdogs

I'm Awesome
Joined
Mar 2, 2012
Messages
569
Reaction score
630
Location
Eastern WA
So here's what I have on my truck. Is this a 3+1? I thought the overloads were supposed to be flatter and not touch the main pack... Or am I just riding around overloaded? :eek:

According to LMC:
4 leaves (3+1) = 6600# GVWR = 1500 truck
5 leaves (4+1) = 7200# GVWR = Light 2500 truck
6 leaves (5+1) = 8600# GVWR = Heavy 2500 truck

You must be registered for see images attach
 

PlayingWithTBI

2022 Truck of the Year
Supporting Member
Joined
Jan 3, 2019
Messages
9,552
Reaction score
14,677
Location
Tonopah, AZ
So here's what I have on my truck. Is this a 3+1? I thought the overloads were supposed to be flatter and not touch the main pack... Or am I just riding around overloaded?
Could be. Yours is different than mine. Here's my 4/1 unsprung.
You must be registered for see images attach


According to LMC:
4 leaves (3+1) = 6600# GVWR = 1500 truck
5 leaves (4+1) = 7200# GVWR = Light 2500 truck
6 leaves (5+1) = 8600# GVWR = Heavy 2500 truck

That may be for other models/years? My 88 was originally 5600#
You must be registered for see images attach
 

boy&hisdogs

I'm Awesome
Joined
Mar 2, 2012
Messages
569
Reaction score
630
Location
Eastern WA
So I went to the junkyard and did some measuring. All of the 1500s I measured (both pickups and suburbans) were sitting at about 21.5 inches from the center of the hub to the top of the wheel arch in the back. Mine is at 19.5" and of all the pickups none of them were touching the overloads like mine are... except for one that had a bed full of engine blocks...

I guess I'll be needing new springs.

I also measured a 1500 with a 4+1 leaf pack and a couple of 8 luggers. After subtracting the 3" lift block, the 4+1 equipped 1500 was sitting at a net 1.5 higher than the 3+1 1500s. (26-3 = 23, 23-21.5 = 1.5 net height gain with 4+1 leaf pack)

There was a SRW 8 lug truck with a 5+1 leaf pack (badges and stickers were missing so I don't know if it was a 2500 or 3500) and it measured 23" and the 4 door dually with a 6+1 measured 23.5"

So it looks like any of the 2500/3500 leaf packs would give you a 1.5" to 2" boost over the 3+1, though this is not an exact science since these were all junked trucks that may or may not have been used and abused for 20+ years.
 
Last edited:

alpinecrick

I'm Awesome
Joined
Jun 12, 2015
Messages
1,614
Reaction score
1,695
Location
Western Slope of Colorado
That says it all right there!



My dad has an 05 2500HD that is 9200# GVWR and there is definately a noticeable difference in harshness there. I've never ridden in a "heavy half" or LD 2500 but with the added weight of my rack and toolbox and the fact that I'm getting new Bilstien shocks at the same time makes me think that the light 2500 springs won't be so bad.

Did you order them new?

HUSKY SPRING 22795

I mis-typed the weight, they are 2025 lb springs. And yes, new Bilsteins also helped the steering.
 

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,617
Reaction score
15,245
So here's what I have on my truck. Is this a 3+1? I thought the overloads were supposed to be flatter and not touch the main pack... Or am I just riding around overloaded? :eek:

According to LMC:
4 leaves (3+1) = 6600# GVWR = 1500 truck
5 leaves (4+1) = 7200# GVWR = Light 2500 truck
6 leaves (5+1) = 8600# GVWR = Heavy 2500 truck

You must be registered for see images attach

Close.

3+1 1500 was 6200# or less.
4+1 F44 1500 was 6600#.
4+1 LD2500 was 7200#.
5+1 was 8 lug 2500 and possibly even SRW 3500.
 

alpinecrick

I'm Awesome
Joined
Jun 12, 2015
Messages
1,614
Reaction score
1,695
Location
Western Slope of Colorado
So here's what I have on my truck. Is this a 3+1? I thought the overloads were supposed to be flatter and not touch the main pack... Or am I just riding around overloaded? :eek:

According to LMC:
4 leaves (3+1) = 6600# GVWR = 1500 truck
5 leaves (4+1) = 7200# GVWR = Light 2500 truck
6 leaves (5+1) = 8600# GVWR = Heavy 2500 truck

With the 6 leaf springs there are differences in the thickness and in the width of the leaves, consequently differences in weight rating.

The LD 2500 was a half ton with the 14 bolt rearend, the 5 leaf spring pack, the larger 3/4 drum brakes, and a larger diameter driveshaft.

Oh, and Bilstein shocks.......
 
Last edited:

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,617
Reaction score
15,245
With the 6 leaf springs there are differences in the thickness and in the width of the leaves, consequently differences in weight rating.

The LD 2500 was a half ton with the 14 bolt rearend, the 5 leaf spring pack, the larger 3/4 drum brakes, and a larger diameter driveshaft.

Oh, and Bilstein shocks.......

No difference in thickness or width of leaves, save for the lower overload. It varied in length and thickness depending on application. Only the real C3500HD got wider leaves.
 
Top