0-20 Shudder
 

Hey guys, I need your help diagnosing a shudder on my truck, before I have a tech look at it.

I've read about the 0-20 shudder on accel, or when towing. I've read that leaf spring clamps or bumpers will help with axle wrap, and also about upgrading to the Raptor tranny mount.

But here's the thing - my shudder goes away when in Neutral, so I can't see it being leaf springs. Maybe tranny mount, but it's not on accel like most others are experiencing, it's mostly when coasting at 15 +/-, or slowing down to come to a stop - whether braking or not. And again, it goes away if I throw it in Neutral. So can't really be e-brake adjustment then, either, right?

Any advise?
2010 F150 FX4 scab 6.5 with Bilsteins front and back, front set to highest, 3" blocks in the back. I've ruled out the 35x12.50's causing it by putting a set of stock wheels back on it.

Could be a number of things, but it's most likely axle wrap. The taller blocks help to make the wrap worse as you've now given the axle a lever on which to attempt to flex the leaf pack against its will. There are ways to prevent the wrap...add-a-leaf, RAS, Helwig helpers.

Like it said...not the end all be all cure to your problem, but likely what you're feeling.