im curious if anyone has put angle shims under the leafs and felt a difference in the truck. my truck cant power brake too well (actually not at all) and shudders when it breaks traction. i have a G80 the drop is a 3/5 on my 04 silverado.

 

i have a 3/4 drop and no issues without shims

 

then what do you think is giving me the shuddering? is that what the g80 does? cause all the does is shake the truck. i can send a video if anyone wants to see it.

 

my truck does the same thing, shims are for taking out vibrations though after its been lowered. I haven't tried to fix mine yet but i know alot of people say they have good results from using spring clamps on the front of the leafs. A more expensive and less jerry-rigged solution would be caltracs. What you are having is called axle wrap.

 

Got the shakes huh?
Well, not all drops work the same on the same type of truck.
You need to buy an angle finder. Craftsman sells one for $11.00. Worked wonders for me today tracing down my driveline angles.
There is a lot of physics and geometry invovled in having the proper driveline angles.
I just did a 2" rear shackle drop and have a shudder at 15-18mph.
Talked to Belltech and McGaughy about it, and they said "most" trucks do not have any issues with vibrations or shuddering with just a shackle drop.
I'm one of the few that do. Go figure.
Anyways, I placed a 2* shim between the leaf pack and sxle with the fat side back. I still had a shudder. Tried the shim the other way, and things got really bad.
I finally got smart, did some driveline angle research and purchased an angle finder.
You need to first measure your tranny angle at the propeller shaft. It should give you a 3-4.5* !downward! sloping angle. Some trucks vary. Then, you need to measure your axle pinion angle at the propellar shaft. It will need to be a !upward! sloping angle.
After you have those two measurements, you will then need to set the axle pinion angle to almost exactly "opposite" of the tranny angle.
Example: Tranny angle is 4.5* negative. The axle angle will need to be 4.5* positive.
When you get the axle pinion angle, it will tell you what degree shim you will need to get to that angle.
Once you get that completed, you can then get the angles where each U-joint meet. You are allowed between 1 and 3.5* working angles.
I know this sounds confusing. I have 6 pages of drive line angle info that I had to read over about 5 times to understand everything.
If you want to rid your shakes and fix your problem, let me know.
I can e-mail you this info. It's up to you and whoever is interested!
Just PM me with your e-mail address, and I'll foreward it over to you.

Jim

 

I don't think its axle wrap that he has. If your talking about wheel hop, then yes, spring clamps or Caltracs are a solution.
A vibration or shudder through the driveline under normal driving is a bad pinion angle.

Jim

 

if i mash the gas off the line, it shudders.

 

do the tires break loose when you mash the gas off the line? it sounds like you have wheel hop. do you get any shuddering or vibrations when you are just driving normally?

 

no i dont just driving. only when i want to break the tires loose it shudders. its weird sometimes very rarely it will do it. but i think on certain roads it wont. i will get the video on streetfire.

 

He says it does it when he foot brakes the truck, so its not pinion angle causing it.