When lowering the rear using longer shackles, if your going to have a vibration can anyone describe what it feels like? In other words will it vibrate at all speeds? Then if you installed the axel shims did it solve the problem? thanks GG

 

This is not your answer, but may be helpful.
When you are done with any rear height changes, your pinion to trans line will need to be checked.
I had wheel hop in my truck with the axle shims provided with the lowering kit.
I took it to a drive line shop, and they shimmed the trans 3/4" .....no more wheel hop.

 

I installed the Ground Force 2" drop shackles on my truck and they caused a very slight driveline vibration at 25-30 MPH. It is not so much a vibration as it is a rumble. Usually if you get a driveline vibe it will be at a narrow range of speeds, above or below that it will be fine. I put the included shims on and the vibe is gone. It's a crap shoot whether you will need them or not. Some do, some don't, mine did.

 

Where can you get the shims?? My shackles didn't come with shims..

 

I just installed my DJM shackles on my Screw last night and I have no vibration at all. I am glad because the DJM's do not come with the shims. I read on here somewhere that the Screws and Scabs are not as likely to vibrate as the single cabs. I dont know if this is true or not, but they said the shims took the vibe away.

Also, mine cleared the bed seam that some people say they had to modify.

 

Just an observation, thus far I've noticed that most folks that got away with shackles without vibrations have trucks with one piece driveshafts...Supercrews and regular cabs. My Supercab had a low speed driveline vibration from 20-30 mph on acceleration, felt like driving over rumble strips, any faster or slower and it wasn't there. That was with 2" DJMs, I raised 'em up to the 1.5" hole and it's significantly improved, but I can still feel a little vibration.

 

I stand corrected. I just remember the Screws not having the vibe problem as much as others. IM free and clear of the vibe an cant be happer with my shackles.

 

That's exactly how mine feels...I don't want to raise back up, because it definitely has the stance that I was looking (especially with the 20's)...I just need to find some damn shims!!!

Edit: Ordered some shims from stylinconcepts...Let you all know if that cures the problem!

 

1Fast89... how did you know what shims to order? Do you have a part number? I have a slight vibration problem too and need to order the shims. Thanks! Dean

 

I called Stylin Concepts and told them the year and model of the truck...Everything I've read states 2* per inch that you lowered it, in other words 2* shims in my case...which is exactly what they told me when I ordered them. The part number is ACC-2"PSK. I haven't installed them due to my schedule, but I plan to install them in the next hour or so...

Edit..Just opened the box and see they sent me the wrong ones (single hole). I guess I'll be calling them up tomorrow morning and hopefully get the right ones!!