The ring gear and bearings are transferred to the new Detroit Truetrac, and then properly torqued into place. Some ring gears and/or bearings may require a press, while others will accept the ring gear and carrier bearings without a fuss. It depends upon many factors, but the majority of installations should offer minimal effort. Remember to coat the fastener threads with a liquid threadlocker prior to torquing them down for the final time. These bearings needed some persuasion to let go of the factory carrier, so the right tool was used for the job. If you run into issues, bearing pullers like this can be rented from many auto parts stores.