so after i put LS calipers and rotors on my car.

Whenever i back up and use the brakes, i hear a shifting noise. then, once i start driving forward, there is a rubbing/bumping sound to the point where i can hear every rotation the rotor makes(they're D&S rotors). its like the pads get shifted and then bump into the slots on the rotors or something. but all i have to do is tap the brakes and they re-align and are ok tilli back up again lol. my question is why is this happening, and what do i do to fix it because i want it to be quiet and work perfectly like my stock ones, cause they are OEM after all, they should be quiet

 

Bobby this is my problem, you heard it right?

Did you replace the caliper/pad clips?

https://www.clublexus.com/forums/sho...d.php?t=292698

 

Bobby-

Mine are quiet as a mouse, especially after I put the EBC Greenstuff pads on them.

As for the problem, it has got to do with the mounting hardware. Does your caliper have the "spring hinged" center piece that both caliper pins help hold down. This "spring hinged" center piece helps push the pads back that half millimeter against the piston instead of being against the rotor.

If this piece has suffered from enough spring rate sag, you might order another set from the dealer. If this piece was not given to you with your calipers, you need to order one from the dealer.

This picture was borrowed from a classified ad in the SC3/400 section:


I am referring to that "T" / "X" shaped piece that spans the caliper, is held in by the pins, and is sloped to use its spring tension to force the pad away from the rotor ever so slightly when the brake pedal is not down.

I would bet money this is the issue. This piece is analogous to the pad clips that Red is pointing you toward on the stock calipers.

 

Never noticed how much larger the LS400 ones are vs the SC's. The SC's were $30 from Carson for the fronts, not sure about LS's.

 

ive got that T/X shaped piece in there, my calipers also came with tthese yellow springy kindo of things that look like they are supposed to push away the pads, but i couldnt find where they should mount.
maybe i'll try and buy another piece from the dealer

 

sounds like u need shims

 

care to elaborate?

 

Shims are the medal pieces that mount between the plastic pad backing and the caliper pistons. I believe there are two of these shims pieces per side of each caliper with a small clip to secure them in place.

If you check out the calipers pictures above, you can see the metal clips I am referring to that holds the shims in place on the rear of the brake pad.

If your LS400 calipers did not come with shims, the dealer will offer a "shim kit" or "shim pack" that will come with all of the metal shims for the entire axle as well as some brake lube to prevent any harsh squeaking from metal-to-metal contact.

 

i've got the shims on there, i think i'll just go buy some of those X shaped things and see if that fixes it

 

two possibles: Make sure rotors are on COMPLETELY. I took mine off (unrelated problem) and put back on but there was were not set correctly. SLIGHT ...almost impercitpble. I remounted. No problem.

Did you use spacers wwhen mounting the calipers? The LS caliper bolts are too long. Spacers (two each bolt) are required on hub side, not wheel side.