How hard is a Cummins 4BT swap?

A 4BT swap into the Defender 110, Jeep TJ and Jeep YJ is a big job, but a good workshop can do it with a complete kit. Most of the time goes into the mounts, the adapter and the wiring.

The usual steps are: remove the old engine, fit the new mounts and the adapter plate, set the engine in, connect the wiring and the engine computer, then fit the cooling and the exhaust. A test drive and a final check follow.

Our kits come with parts that are made to work together, which saves time and guesswork. What we list: Cummins 4BT kits for Defender and Jeep Wrangler.

Before you start, check your local rules for registration and road tests after an engine change. We supply invoices and documents that help with this.