Shackle lift MPG Drop???

If it was a sudden drop of that many mpg's, sounds like a single failure of something. Usually for plugs fouling up, plug wires corroding, you know, tune up type shit, it gets slowly but progressively worse over time until you maybe have a plug fail and start misfiring.

 

yeah its none of that then. brake check it is!!

 

You wont see a measurable gap between pads and rotors if they are running properly...

Just curious, why did you decide to run shackles offset from one another to adjust the lean? Wheelers for example sells stackable steel plates that go under your leafs to correct that or just to adjust ride height if needed. That way you dont mess with your pinion angles as much...

 

He'll be able to tell if the pad is pressed into the rotor when the brake is not applied.

 

+1 on this

brake pads are always making contact with the rotors. the brakes work when high pressure is applied. when no pressure is applied, the brakes relieve any friction and free the wheel. there is a trivial amount of friction occurring between the pads and rotor otherwise.

did you remove your rock guards or remove/replace your front bumper? its more likely that the lift exposed more of your front suspension and has increased wind resistance from not being as aerodynamic.

 

I added a bumper several month ago but the drop in mpg occurred after the shackles. there were several months between the installs. i bled my brakes a little last night because my master cylinder was over the MAX line... i heard if there is too much it could cause brake drag. i dont know if im imagining it or not but it seemed like maybe there was some improvement. i dont know probably just my imagination.

 

im going to crank up my front end a little bit this weekend when i go home, my uncle has my wrenches. i have a pretty intense rake right now. maybe it will help if its a little less aggressive.

 

yes, that was my thought process. would that not serve as just a cheaper solution to the same problem?

 

I noticed a drop in mpg when I put my lift on. Same tire size, no other mods, etc. only thing I can think of is the change in aerodynamics.

 

yeah i was thinking that might be it. im gonna adjust my front coilovers up tomorrow night when i get home.

 

Have you tried putting both shackles on the same setting? That seems like the first logical solution.

 

ill try that but its only about a half inch. the drivers side has the all pro 3 inch leafs and the toytec shackles set to 2 inches. the pass side has the same leafs and the shackles set to 1.5 inches. my parking brake cable has a some tension on it but still clicks quite a bit when i pull it out.

 

I'm just saying it seems liek the first logical thing to troubleshoot.
-Truck is fine
-Install shackles in an uncommon way
-Truck now runs funny

 

ill check it when i get off work. im wondering if its the near 5 inches of lift i have back there. paired with not having any weight over the axle.

 

Yeah, maybe your rear driveline angle is so outta whack that it's causing resistance at the U joints?

 

i did a carrier bearing drop. but i guess that might not do much for the rear joint at the rear axle.

 

The shims would certainly be the cheaper option.. Those are half inch plates. They also offer thinner ones on there aswell. I think maybe in the miscellaneous suspension parts page possibly? If not they're in there somewhere.

**edit** no i was wrong the thinner plates are an OME product, so they're listed in that category! They are 5mm thick, like 9 bucks for one. Stackable and dont come with center pins, where as the ones i linked come with new pins, they are stackable too.

 

Haha yeah, thanks for the +1! Certainly no gap there with the pads and rotors, there isnt even movement of the pads they stay so close to the rotor. A visual inspection would yeild virtually no results. The OP would be better off either just putting a finger on the rotor after a short drive, if it burns ya the caliper is dragging. Or and also a very easy option would be to simply jack up the front and manually spin the wheel by hand. If ther is significant drag, well then its prolly dragging. However with ADD this might be kinda hard since you will be trying to spin all that front end shit. If OP has manual hubs this will be a good route to check for sticky calipers otherwise do the heat test, also if its just one caliper dragging there would be a slight pull to the left or right...

 

Checked the wheels last night when i got home. Jacked it up and spun the wheels, i got several rotations... i dont think anything is dragging. i called allpro and talked to one of the install techs and told him what i had going on. he thinks it might be aerodynamic related. ill update you guys this weekend after i crank up the front end a little, its not quite keeping up with the rear right now.