Well I installed the western chassis 3-5 drop kit. The kit includes A-arms, springs, shackels, hangers, and I added four doesch-tech shocks. Well all was well but when it got on the ground it sat lower in the back and the ride was UNBEARABLE!!!!! So I moved the shackle and hanger to the lower postion (raises the truck about an inch) and now it rides soooooo good. But I still have a problem, I forgot to put in the shims that go inbetween the axle and the leaf springs, now every time I accelerate from the line I hear a HUMMING SOUND from the back. Why is this?? Is it because I didn't put in the 6 degree shim???? And if that is the reason should I drive it live this or can I damage the drivetrain????? Do I need to park it untill I can take the time to work on it. HELP ME out guys this is my first mod and I don't want to turn it in to a nightmare.

P.S. It only makes the noise if I accelerate quicklly from the line.

 

Put in your shims and see if your driveshaft is rubbing.

Daniel

 

uhmmming is never a good thing!


your really need those shims to adjust the angle of the drive shaft.

now get to work!

 

Check your bump stop clearance on the rear axle. If only one inch made that big of a difference, you might still be too close. Mine were about 2" above the axle. Changed to shorter stops and the ride improved dramatically. Didn't realize I was hitting the stops until I installed shorter ones.

 

What was 2" above the axle?? I put shorter bump stops in but I might shorten thoughs a bit too. Rode the truck some more and I wish the ride was a little better in the back. Thank god I live in Scottsdale were the roads are smoooooth.

 

speedRacer5,

I have the same WC 4/6 drop (3/5 on the L), keep in mind that the drop is different on my L with the added weight of a hard tonneau and two batteries in the bed…

When finished, I put the stock shackles back on and used the lower hole in the hangers. This gave me roughly a 1.5-inch clearance between the new bumps and the axle, no bottoming out (so far) and looks great…

The original installation was done for me and the shims were forgotten. My truck felt very rough when moving forward from a stop, I had them install the shims and the ride smoothed out (no more hum or binding)…

You mention ride in the rear, I don’t know if you’re referring to up and down or sway. Have you changed your rear end links? The kit came with front end-links but no rear. There are other posts on rear end-link kits or you can cut your links, shorten them and weld them back together…

 

QuickBrick-

Thanks for the info, What I mean about ride in the back is that it hits the stops on every little bump. I want to put the stock shackels back in but Sporttruck direct told me it would change the pinion angle and I shouldn't do it????? So they gave me a different set of shackels to try that should raise the truck 3/4 of an inch, plus I'm going to cut the short bump stops I installed as well. Hope this works!!!!!!!!!!!!

 

speedRacer5,

I found that members were changing their pinion angle a bit more negative than needed for improved launch, so I stayed with the 6-degree shims… The general rule as I have read it is, 1 degree per inch drop… Most were going between 4 and 6-degree shims for a 4-inch rear drop… I have no ruff ride, she launches well and no noise or uneven ware…

Here is a thread that might help…

https://www.f150online.com/forums/sh...e&pagenumber=1