Have a 2006 Navigator. I bought a 3" spacer kit. The spacers are 1 1/2", was told that they will give 3" lift. I'm going to make my leveling arms longer. My question is, how long do I make my arms? 1 1/2" or 3"?

 

You'll have to get some material and fabricate an extension.

 

I know that

 

The question is how long?

 

The same amount you lifted the truck. If it's 3" then the rod has to also be extended this same 3". This might not be your exact sensor but the idea is the same for all.

 

Even though the spacers are 1.5" the rods should be 3"?

 

No, I said you extend it the same amount you lift the truck. If you lift it 1-1/2" then extend it the rod 1-1/2". If you raise it 3" then extend the rod 3". I see no way you can use a 1-1/2" spacer and get 3" of lift out of it unless you're stacking the two 1-1/2" spacers. But if you do have some way to make the 1-1/2" spacers lift the truck 3" then the rod should be extended 3".

 

It's a spacer from CTS. They said that the spacer is 1.5" and will lift my Navigator 3" because of the geometry of the suspension. Anyone else hear of this?

 

That would depend on where the spacer gets inserted. If for example the 1-1/2" spacer is positioned halfway out from the suspension pivot point like shown in this simple drawing, you will end up with 3" of lift at the end.

 

Actually it's going on top of the air bags.

 

Then all you're basically doing is making the airbags 1-1/2" taller. You will only get 1-1/2" of lift and even then it will only happen after the extension modification to the sensor rod. The sensor works by measuring the distance between the unsprung suspension (on the ground) and the sprung suspension (the body). So just adding the spacers will have no affect on that distance.