Compatible With: Jeep T18 4 speed transmission rebuild kit is a complete rebuild kit with synchro rings. You can identify this transmission by the casting "T18" or "13-01" and it has an iron case. It is important to measure the key slots for your 3rd and 4th synchro rings to make sure you get the correct rebuild kit. This rebuild kit comes with 3rd and 4th synchro rings that have 10 millemeter key slots. This kit includes all the bearings, synchro rings, seals, gaskets, complete small parts kit (That includes snap rings, thrust washers, needle bearings, etc.)