2014+ Lowering / Drop Kits

Joshua022 · September 6, 2014

I want to do a 3/5kit on my rcsb sierra because it sits like a 4wd.

But I'm worried about the whole shortening the driveshaft problem, is that on every trucks or only on those made before a certain date? If so what's the date and how do I see when mine was built?

keakar · September 6, 2014

I want to do a 3/5kit on my rcsb sierra because it sits like a 4wd.

But I'm worried about the whole shortening the driveshaft problem, is that on every trucks or only on those made before a certain date? If so what's the date and how do I see when mine was built?

im just repeating what I think I learned about it from reading these threads so im pretty sure you only need to do that shortening of the driveshaft with big lowering kits that flip the axle over the springs which I believe would be the 4/6 or bigger drop kits increased spacing cause by lifting and rotating upward on the rear end of the leaf springs.

im sure that someone who knows more about exactly when you have to start looking to see if you need to start cutting the drive shaft lengths will chime in with more accurate info on this

Edited September 6, 2014 by keakar

whodatfan · September 6, 2014

Anyone reuse the factory nuts off the u bolts? I ordered 4 gm #15002781 and all you get is the damn u bolt. No nuts. As expensive as they are you think you'd get nuts and washers included.

nate538 · September 6, 2014

Anyone reuse the factory nuts off the u bolts? I ordered 4 gm #15002781 and all you get is the damn u bolt. No nuts. As expensive as they are you think you'd get nuts and washers included.

You will be fine with the old nuts

Slo281 · September 18, 2014

So if I'm reading most of this right I can't just throw on a shackle kit without modifications or shock problems? Have a belltech shackle kit arriving today and after reading this thread I'm having doubts. If I level out the front with a leveling kit will I have the same issues as far as modifications needed?

No Tyme · September 18, 2014

This thread is getting impossible to follow: We need to separate the lowering shackles from the drop kits where you guys are slamming your trucks 6 inches... Does anyone know how to go about this.

whodatfan · September 19, 2014

So I want to clarify a post I made about the shim positioning on lowered trucks. I ordered the DJM 2 degree shim kit for my rear drop consisting of 2" shackles, rear block removal, and OBS u-bolts. I assumed that you needed to install the shims to roll the rear end upward because the shackles rolled the pinion downward, but that is not the case. It is just the opposite. Lowering the rear of the truck raises the axle and flattens out the driveshaft decreasing the downward slope of the shaft from front to back. To regain the proper angle, the axle actually has to drop down towards the ground. With that in mind, for trucks with leaf springs on top of the axle, the thick part of the shim must go towards the front. For trucks with the leaf springs underneath the axle, the thick part of shim goes towards the rear of truck. My previous post on this was incorrect and I stated the opposite. Here is a link to the page explaining this for the exact DJM kit I purchased:

Adjusting the driveline angle is usually necessary when lowering a vehicle. When a drive shaft is out of line, the rear U-joint may cause vibrations at high speed. When using flip kits, the correct pinion angle is built into the bracket. DJM Suspension's "Universal Axle Locators" allow for infinite adjustments of the pinion angle.

When using hangers and shackles, pinion shims are needed. Pinion shims or wedges are used to rotate the axle and line up the drive shaft. On most applications, Stylin' Concepts and DJM recommend completing the installation and test-driving before adding shims. Many vehicles will not have any vibrations so shims are not needed.

A common question we get is, "Which way does the shim go?" The answer depends on the application. Pinion shims are most commonly used for hangers and shackles on full size trucks (Chevy, Ford and Dodge). These vehicles have the leaf springs on top of the axle. Lowering the vehicle basically raises the axle. To correct the drive line, the front of the axle needs to be tilted down. The shim would be installed thick end forward. For vehicles with the leaf spring below the axle, the shim would be installed thick side to the rear.

In the center of all leaf springs is a bolt with a round head. This bolt holds the leafs springs together and aligns the axle. When adding a pinion shim the bolt does not protrude far enough to align the axle correctly. DJM shim kits include new center pins with a spacer to raise the bolt off the leaf springs. This will align correctly with the axle.

Changing the pin and installing shims is an easy job. Using two clamps, one on each side of the bolt, remove the nut and center bolt. Slide the spacer on to the bolts and secure with the nut provided. Cut off the excess bolt and set the shim between the axle and the leaf. Line up the pin with the hole in the axle, install U-bolts and tighten.

http://www.stylintrucks.com/articles/0705_djm_pinion_shims.aspx

Hope this helps out the confusion on the shim placement.

Edited September 19, 2014 by whodatfan

racerkvn · September 19, 2014

This thread is getting impossible to follow: We need to separate the lowering shackles from the drop kits where you guys are slamming your trucks 6 inches... Does anyone know how to go about this.

I don't think it needs to be separated, people just need to read and comprehend the entire thread. There has been tons of very useful information posted on here from everything from leveling the truck to a 6/9 slammed ride on bags. It's getting impossible because people want a one size fits all answer and that is just not the case no matter how many people did the exact drop you are interested in. Let's face it, some of our trucks were built on a Friday or a Monday, some trucks just require more adjustments than others whether it's shims to correct the driveline or cam plates/bushings for the alignment no matter how many people did the same drop using the same parts.

Dylan199 · September 19, 2014

So I want to clarify a post I made about the shim positioning on lowered trucks. I ordered the DJM 2 degree shim kit for my rear drop consisting of 2" shackles, rear block removal, and OBS u-bolts. I assumed that you needed to install the shims to roll the rear end upward because the shackles rolled the pinion downward, but that is not the case. It is just the opposite. Lowering the rear of the truck raises the axle and flattens out the driveshaft decreasing the downward slope of the shaft from front to back. To regain the proper angle, the axle actually has to drop down towards the ground. With that in mind, for trucks with leaf springs on top of the axle, the thick part of the shim must go towards the front. For trucks with the leaf springs underneath the axle, the thick part of shim goes towards the rear of truck. My previous post on this was incorrect and I stated the opposite. Here is a link to the page explaining this for the exact DJM kit I purchased:

http://www.stylintrucks.com/articles/0705_djm_pinion_shims.aspx

Hope this helps out the confusion on the shim placement.

The shim is used for a shackle and hanger (4" drop). I did not use any shims for my shackle and block removal. I don't have any vibration issues whatsoever.

keakar · September 19, 2014

The shim is used for a shackle and hanger (4" drop). I did not use any shims for my shackle and block removal. I don't have any vibration issues whatsoever.

I think his point was that every truck is a little different so every lift or drop is going to also be a little different.

he was correcting his comment about what HE did to HIS truck and not referring to your truck or anyone elses truck, hence the every ones truck is different comment.

I think by you quoting him your comments could add to someones confusion about what is or isn't ":needed" vs what "might" need to be used in some situations.

earlier in the thread it was mentioned that its best to do your lift or drop and then measure your driveline angles and THAT determines if a shim is needed or not and what size might be needed. I think its important to mention that so others just coming into this discussion can follow along without getting confused why some say its needed and some say its not needed.

Danny_Sierra · September 23, 2014

I have a 2014 Sierra RCSB and i'm on the fence of buying the McGaughtys 2/4 drop. i think its perfect, the front is going to look badass, only problem is the rear..it sits so high, 4 inches wont level it down, can I throw on the shackles after the 2/4 drop kit. Also im going to run 22" wheels, the black gloss 5 spoke that gm sells. Any rubbing issues or problems I can expect with the 2/4 drop and 22s? and possibly the shackles after?

Danny_Sierra · September 23, 2014

whoops sorry, i mean the rough country 2/4 lowering kit http://www.roughcountry.com/gm-lowering-kit-723-20.html

keakar · September 23, 2014

I have a 2014 Sierra RCSB and i'm on the fence of buying the McGaughtys 2/4 drop. i think its perfect, the front is going to look badass, only problem is the rear..it sits so high, 4 inches wont level it down, can I throw on the shackles after the 2/4 drop kit. Also im going to run 22" wheels, the black gloss 5 spoke that gm sells. Any rubbing issues or problems I can expect with the 2/4 drop and 22s? and possibly the shackles after?

you can always add the shackles later but then the rear will be 1" lower then the front.

stock stance has the rear 3" higher then the front so a 2/4 kit will drop the whole truck but have the same visual leveling affect as a 2" rear drop shackles and leave it with only a 1" higher stance in the back which is perfect to be as flat as possible while still letting the bed drain well. at a 1" rake in the back it will still "look" level even though its not exactly level

Edited September 23, 2014 by keakar

Danny_Sierra · September 23, 2014

you can always add the shackles later but then the rear will be 1" lower then the front.

stock stance has the rear 3" higher then the front so a 2/4 kit will drop the whole truck but have the same visual leveling affect as a 2" rear drop shackles and leave it with only a 1" higher stance in the back which is perfect to be as flat as possible while still letting the bed drain well. at a 1" rake in the back it will still "look" level even though its not exactly level