Do you have the latest version, Fifth Printing, of your owners manual? If not, download it from Jeep.com. It say 87- 89, on page 542.
Jeep Owners | Download an Owners Manual 2004 - 2011 | Jeep
This link has OMs through 2014.
Jeep Owners | Download an Owners Manual 2004 - 2011 | Jeep
This link has OMs through 2014.