So I searched the tech forum and found the TSB that has the instructions on how to cure what is known as the drive-away shudder. Basically, when the truck is loaded, you'll feel a shuddering or vibration when you accelerate from a dead stop. The TSB says to get a shim and a couple of new bolts from Ford that should clear up the problem. (Some trucks may need more than one). <o></o>
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The dealer orders the shim and bolts, but I don't look closely when I pick them up. I get home and rip the bag open to find that the shim is nothing more than a piece of ¼ by 1¼ flat bar with the holes drilled in it. Oh, of course it has the Ford logo and the part number. The part was $43.55. <o></o>
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And the bolts they sold me were smaller than the bolts on the truck.<o></o>
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So buyer beware – you could make the shim for about $2 by cutting and drilling it yourself and reusing the factory bolts.<o></o>
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I put just one shim in mine (’07 F-350 crew cab 4x4) and the shudder is gone. I can’t believe just a small change like that would make any difference, but it does.

 

You changed the pinion angle. It does not take much.

 

Where is the shudder coming from? Did it just start or did you mod your truck then it started.

 

The issue can happen with a new truck, or with a truck where the suspension is modified in some way, usually lifted. With stock trucks, it may be notices more when towing or hauling a hefty load.

 

It's an axle wrap problem. The longer the leaf springs you have the more likely it is to happen. Weight enhances it.

 

Ahhhhh. I just replaced my rear blocks with 5.5" blocks. Started noticing the shudder soon after. I have a fab shop capable of making all types of parts, I'll probably make the shim and move on.

 

Where's the shim go?

 

i feel mine when im backing up with my fifth wheel hocked up it feels like a grab and release a bunch of times mines a 03 ls 4:10

 

Is this a shim to drop the carrier bearing down? I've been thinking of shimming my carrier bearing since putting 5" rear blacks in my 250.

 

Yes, drops the carrier bearing.

 

Guess I'll have to make one for my truck then.

 

Too many shims under carrier brg can give you a shudder as well, u/joints are not going to last as long being their workin lots harder with bigger angles and turnin bigger tires.

Replaced mine at 55K and brg needed it too.