Does anyone know who manufactures polyurethane bushings for our (G37) rack and pinion mounting points? I need to replace mine since they are shot, and they dont sell OEM ones.

Energy Susp makes them for the G35, the steering rack on those cars is mounted at different locations but im thinking the polyurethane bushing itself might fit on the G37s rack and pinion. Has anyone done this before?



Thanks in advance!

 

Never done it on the G37, but Energy Suspension is probably your best bet. If you get them out and measure them you'll probably be able to find an application that fits.

Is your rack making noise? How'd you discover they need replacing?

 

Ive been searching for the cause of my steering wheel shudder for while now. Took it to a shop and they noticed too much movement on the rack and pinion itself (mounting points). Even though neither I nor the shop believe that is the cause of the shudder I would like to replace them with polyurethane ones. Nothing is making noises or anything.

For now we've narrowed it down to a bent wheel or bad tire (which are basically new, 4k mile Nitto Invos), the problem is that they balance out perfectly on the wheel balancing machine.

 

I'm no expert on it, but I don't think worn steering rack bushings would cause shuddering in your steering wheel. I've had to replace badly worn ones on other cars before, and the main issue was knocking noise when turning the wheel (particularly when turning sharply) and a lot of play in the wheel. No shudder at all. Also, I've never had to deal with work steering rack bushings except on older higher mileage cars. Like 12 or 13 years old with 200K on the odometer.

Did you try swapping wheels front to back to see if it persists? If it doesn't, then the issue is definitely with one of your front wheels.

 

Put some OEM 18" sport wheels from a G37s sedan and the shuddering is still there... Frustrated plus the shop nicked one of my brake calipers ..

Any ideas? Bent hubs? I did have h&r bolt in spacers for a while, but removed them thinking they where the cause of the vibration/shuddering.

 

Make sure your Nitto tires are not out of round, in which case it could present as wheel hop and tread travel. The tire could balance out all day long, yet at highway speeds, the vehicle will shimmy like one or more wheel and tire is out of balance or round, even after road force balancing. A while back I bought 4 Nitto NT421 Q'S and three of the tires had the wheel hop and tread travel. Only the 4th tire proved not defective, and it came from a different run based on the DOT's.

I like Nitto, but would be hard pressed to buy them again. Kudo's to Discount Tire Express for refunding the tires (both cost and shipping) and paying to tear down the Nitto's and reinstall an entirely different set of tires. The whole scene made me reluctant to do internet tire deals.

 

Thanks for the replies, apparently my rotors were so warped they caused the shuddering even when not pressing the brakes! I knew they where warped but since Ive never thought they would be the culprit. I would like to clarify that the shuddering occurred when NOT using/pressing the brakes.

Resurfaced the rotors and the vibration is gone...