Nissan 370Z Forum - View Single Post

TBatt · 07-23-2016, 03:12 PM

Earlier this week I installed my new AG wheels and tires. When I was putting the front wheels on they were not seating very well onto the hub so I used the lug nuts to pull the wheel up to the hub, After torquing the lug nuts to 85lb/ft I took the Z for a quick drive. All was good till I got up to about 30mph and then I felt a weird vibration and after making the next turn a strange sound was coming from the left front. Babied her home and found that the left front wheel was no longer tight. Re-torqued the lug nuts and went for another drive. Better but not quite right. I decided to just drive the car and see if the tires just needed to be run in.

The next day when I got home I rechecked the torque on all of the wheels and both front wheels had become loose.

I decided that the rust and crud that was on the hubs were probably causing the problem. Well I was right! After cleaning the rust and crud off of the front hubs the wheels are remaining torqued to the proper value AND the vibration is GONE.

I also had started getting some brake pedal vibration and was going to see if the Flex-Hone for rotors would clear that up. It did! What the flex hone does is remove the pad deposits that are laid down on the rotor during the bedding process so that bedding can be redone. What a lot of people call rotor warp isn't. It is more than likely an uneven deposit of friction material onto the rotor. This causes the rotor thickness to vary and as the pads squeeze the rotor it causes the whole braking system to pulse. By removing this deposit and cleaning up the surface you can start the bedding process over with a clean rotor. Trust me, it works and the Flex-Hone is worth the $40 price. Search on Amazon for it. It comes in coarse, medium and fine grits. I got the medium and it does the job and quickly. You will spend about a minute per rotor side. If the hone starts to chatter and bounce back off on the pressure. Let the hone do the work. Only a slight pressure is needed. Make sure you have a good swirl pattern around the entire pad area. Clean the rotor with brake cleaner and let dry. Wipe if down good before installing it. I wear nitrile gloves so I don't get any oil from my hands on them. The cleaner they are the better.

Okay enough about the rotors, lets get back to the hubs.

The brake rotors and wheels mate to the hubs so they all must be perfectly clean in order for those components to seat properly. Any debris that is caught between these components will cause problems.

To do the cleaning I used a high speed moto-tool with a wire brush wheel and cone to remove the rust. Don't run the wire wheels too fast as they will shed their wire parts! Wear eye protection! Take your time and let the brushes do the work. It only took about five minutes per hub to get them looking like new again. After the wire brush cleaning I used brake cleaner to remove all of the dust and crud. After the brake cleaner evaporated I decided to coat the hub with Permatex rust treatment. This neutralizes the rust so that hopefully it won't come back anytime soon. The product turns the rust black. I did not allow the product to dry, I made sure to wipe it all off after allowing it to soak into the rust for about five minutes. This seemed to work well and this way no additional build up was allowed so the parts retain the original dimensions.

To remove the rotor first secure the caliper with a piece of wire so that it is not hanging off of the brake hose. Not doing this will put undue strain on the hose and could cause brake failure. After you have the caliper suspended, remove the two 22mm bolts that hold the whole caliper assembly to the front hub assembly. Slide the caliper off of the rotor and push it out of the way while it is hanging on the wire you installed. The rotor should slide off but if it doesn't Nissan has thought about this and has included a bolt on the rotor that can be used to break the rotor loose. Take the bolt off and remove the spacer and reinstall the bolt. A couple of turns of the bolt will jack the rotor from the hub. My wheels do not have a relief for that bolt so it had to be removed in order to mount the wheels. Keep the bolt in a safe place for when you need it.

I also cleaned the wheel hub area as it had crud on it from the dirty hub.

I hope this was useful and rep points are always welcomed!