Have used them to fix Tacoma lean before. Requires an alignment afterward, but no adverse issues otherwise.

 

You can do the front and rear spacers. Shouldn’t make a difference If you have a lift or not. It’ll align fine and as long as you have enough thread left on your leaf u bolts to safely put the rear shim in you’ll be good.


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I have a 2016 GMC Canyon SLT with a 4" Rough Country suspension lift.

I recently bought the Supreme Suspension 0.5" lean correction spacer for my front driver side strut. I can't do the factory fix because the factory or dealer fix, is to put a shim on the leaf spring in the back, and since I have the lift, I cant do that fix. So I asked a mechanic if he could do it, and he said that the spacer would mess up the alignment and geometry of the front end of the truck. So has anyone ever used something like this on a lifted vehicle, and if so, does it cause alignment and geometry issues.

I can provide pictures or any other info if needed

Thanks in advance for your guys' input!

I would carefully measure all four corners of the truck to figure out exactly what is low. Then use a spacer there.
Like @Skrongbed said you can do front or rear.
It is very possible you will see one complete side low (like the left) then I would do the back, simply because it's easier.
Why exactly do you say you can't do the back?

 

The problem with using the shims in the back in general boils down to effective spring rate. The front coil springs on a truck are often a linear spring rate where the rear springs fit in the progressive rate category due to overload leafs. The leaf spring rate prior to overload leaf engagement is also much lighter than the front coil springs to account for a good ride quality with nothing in the bed. Therefore, adding a shim in the front will be much more efficient at correcting lean because the linear nature of the coil springs will have a more linear impact on ride height.
On the Tacoma and some early 2000's GM full size 2wd trucks, I observed a 1/4" shim in the front would usually lift that side about 3/8" to 1/2" and change the rear of the truck as much as 1" to 1 1/4". If you have adjustable coil over shocks in front, you can add spring preload to lift it.

i encourage you to experiment using a floor jack. Find an appropriate frame lifting point on the low side in front. Measure and jack up on the low side until the front is level. Best to jack up on frame between front bumper and front wheel. Now go to the rear of the truck and see how close it is. That will give you a good indicator if shimming the front will solve your lean.