Adding Leafs To Stock Springpack

tyhuck · February 20, 2011

Im looking for a way to decrease the amount of axel wrap that my stock 05 Silverado has. The block on my truck now looks to be about 2 - 2 1/5" tall. I know the block in the rear is not that big, but Im looking for an alternatve that will allow me to remove the lift block and still maintain the factory rear height.

I thought about replacing my springs with a set from a 2500. If I do that what year models will fit?

I also thought about adding some leafs from other factory packs. Has anyone done this? How much of a job was it?

FarmerDave · February 20, 2011

If you remove the block you will have nothing to correct pinion angle. You need some form of shim in there if you plan to remove the block.

music · February 20, 2011

If you add a leaf (+2"), and remove the block (-2"), wouldn't the angle stay the same? The "add a leaf" I looked at stated it would raise the rear ~2".

FarmerDave · February 20, 2011

The height stays the same, but the axle angle relevant to the drive shaft is not. If the angle isnt optimized, your gonna replace U-Joints quite often.

tyhuck · February 21, 2011

Do the HD trucks have a shim or something to correct the pinion angle? Thats ultimately what Im wanting to use is the 2500 springs if I can afford them. But, the HD springs are $300 a set, and I can get a set of 1/2 ton springs for $150-$200. I dont wnat to mess with diassembling a spring pack, but If I can save $150 then it might be worth it.

Also, whats the verdict on reusing stock U-bolts?

8.1HD/ALLISON · February 21, 2011

I have never seen a stock block marked front or rear, so I wouldn't think they are tapered for pinion angle. Aftermarket lift blocks can be, but never seen a stock one. On the u bolts. You should replace them everytime, however I know they get re-used all the time. Thats your call, balance out your budget vs. peace of mind.

FarmerDave · February 21, 2011

Unless you torque the U-bolts past yield strength, you can use them over and over again.

tyhuck · February 21, 2011

Unless you torque the U-bolts past yield strength, you can use them over and over again.

What kind of torque specs are we looking at?

FarmerDave · February 22, 2011

Well, I cant remember spec but I think its around 140 lb/ft.

And Manufacturers would not design a fastener that will be potentially removed, ever with a torque to yield spec.

Easiest way to check if you over torqued, compare it to a new one, if its the same length, your ok.

If its stretched, throw it out.

Torque stretches the bolt, it returns to original size if not over torqued.

Side note: usually stock U bolts can be used forever, its over sized U bolts that are made for huge lift blocks that I would recommend not reusing.

tyhuck · February 22, 2011

Hey 8.1HD, can you snap some pictures of your springs and post upt some spec on the pack thickness and the leaf thickness? I know you have more leaves in your pack, but Ide like to make some comparisons.

8.1HD/ALLISON · February 22, 2011

I sold the 1/2 ton truck that I had swapped springs on. Is that what you wanted pics on? I took the stock 3 leaf pack out, installed the 3/4 ton 5 leaf pack and left the 1/2ton lift block in. Or were you wanting a pic of my 3/4 ton with the add-a-leaf?

chakis24 · February 23, 2011

I sold the 1/2 ton truck that I had swapped springs on. Is that what you wanted pics on? I took the stock 3 leaf pack out, installed the 3/4 ton 5 leaf pack and left the 1/2ton lift block in. Or were you wanting a pic of my 3/4 ton with the add-a-leaf?

did you need to install longer shocks or were you able to use the stock ones when you swapped them in the half ton?

tyhuck · February 23, 2011

I sold the 1/2 ton truck that I had swapped springs on. Is that what you wanted pics on? I took the stock 3 leaf pack out, installed the 3/4 ton 5 leaf pack and left the 1/2ton lift block in. Or were you wanting a pic of my 3/4 ton with the add-a-leaf?

Just snap a picture of your current leaf pack with a tape measure in front of it. It would have to be pretty close so we can read the tape, but I think it would be pretty easy. Also, if you could point out the AAL if its not obvious, that would be great.

Im mainly interested in things like leaf thickness, number of leaves, and total thickness of the pack.

SpeedHoles · February 23, 2011

are you experiencing a lot of axle wrap???

Could just get a set of Caltracs.

Ditching the block is a good idea though, I did when I went to a set of BDS ride glide leaf packs and I no longer use any sort of block. Might want to look into them if you're looking for options, will definitely ride better than the 2500 pack on your 1500, unless you carry loads often.

Something else might be a shackle flip, which will ride and flex 100X better than what you have now or especially 3/4 ton springs. Only issue with that is you might end up about an inch higher out back than you want, with no block...

I'm personally not a big fan of AAL's either... kind of bandaid fix and rides horrible, IMO.

You might look into a zero rate too, but they are only slightly less susceptible to axle wrap than a block but you can get them custom made with pinion angle machined into them for whatever you need.

Pinion angle should always be addressed when raising or lowering your rear end, regardless of method. Wedge shims are cheap and easy though.

8.1HD/ALLISON · February 23, 2011

I sold the 1/2 ton truck that I had swapped springs on. Is that what you wanted pics on? I took the stock 3 leaf pack out, installed the 3/4 ton 5 leaf pack and left the 1/2ton lift block in. Or were you wanting a pic of my 3/4 ton with the add-a-leaf?

did you need to install longer shocks or were you able to use the stock ones when you swapped them in the half ton?

The stock ones were long enough, but not by much. z71 i'll see if I can get a few pics tonight when I get home.