The next step in the $3K JK Project is to install a set of wheel spacers to prepare for the larger tires. We have decided to use the 315/70R17 (35″) Goodyear Duratrac tires on our JK with the beautiful stock Hard Rock wheels. Side note, heard these wheels called the Rubicon snow flake?
The JK factory 7.5″ Rubicon wheel has 6.25″ back spacing which is too much for a wide tire like we want to use. Tires this size will rub the rear suspension components and rub the front sway bar. Optimum back spacing for a ~12.5″ width tire is 4.75-5″.
First a note about these spacers. “Technically” these spacers are not spacers, they are adapters. Spacers (seen on the left) are rings that widen the axle width by adding space to the wheel mounting surface. These rings use the original studs and cause the wheel lugs to have less thread area. In many states spacers larger than 1/4 inch are illegal. Adapters mount to the wheel hub using the original lugs and provide new proper length lugs for the wheel to mount to.
Often these adapters do adapt a bolt pattern but they don’t have to. Many companies make adapters to widen the JK axle width and there are many companies that offer less than standard adapters of poor quality. Avoid the cheap ones.
Our choices would be Teraflex or Spidertrax. Both these adapters have proven track records; we chose Teraflex spacers for the jeepfan.com JK.
Teraflex makes the perfect sized adapter for the JK that is 1.25″ wide and takes the wheel offset from 6.25″ to 5″. The adapters come with lug nuts and pre-installed lug bolts.
You will need some red thread locking compound before you get started. Installation takes about an hour.
Installation
Remove the wheel. Remove the assembly washer rings from the hub, they will not be reused.
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Temporarily install the adapter. On some installations you will need to grind the original lugs to prevent the lug from extending past the edge of the adapter. Not doing so will cause the original lugs to contact the wheel and prevent the wheel from proper installation. Our experience shows the rear is more likely to need grinding. Usually 1.5″ spacers don’t require grinding.
Factory Jeep wheels have recessed areas in-between lugs and don’t usually require grinding.
Place some thread locker on each lug bolt and install the adapter tightening the lug nuts in a star pattern. Torque to 95 ft lbs.
Install the original wheel, repeat on the other 3 wheels.
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Maintenance
Check the torque on the adapter any time the wheel is off and during tire rotation.
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Your Jeep is now ready for wider tires.
Visit the $3K JK article to see the completed Jeep.
