Rebuild Your Dana 20 at Home

    Fix Your Tired Dana 20

    Jay KopycinskiPhotographer, Writer

    The Dana 20 transfer case is a medium-duty, gear-drive unit that was manufactured from about 1962 to 1979. It is a part-time, manual-shift t-case that was found in Jeep, GM, Ford, and some International Harvester vehicles. The cast iron housing helps contribute to its reputation as a robust and reliable transfer case.

    We had a Dana 20 from an old Jeepster with a TH400 transmission that was in need of a little TLC. It had a lot of years and miles on it, and was popping out of gear on occasion. It was time for a home workshop rebuild of this unit. We contacted Novak Conversions for advice. The company assured us that a Dana 20 rebuild was straightforward, and Novak offers a master rebuild kit with online instructions for the process. This kit includes the company’s special hardened intermediate shaft, and we also opted to install Novak’s new billet rear-bearing cap that shims internally using an O-ring for sealing.

    With our Dana 20 pulled out of the Jeep, we did a little external cleanup and then tore into the rebuild. Follow along as we freshen up a 50-year-old transfer case and ready it for many more wheeling miles. We completed the rebuild using mostly common mechanic tools on a home workbench, and did use a press to remove and install a couple of bearings. We also used feeler gauges, pullers, and a dial indicator during the process.

    All our gears looked to be in good shape, so we proceeded with the rebuild to replace wear items with the Novak kit. This article is not meant to give you comprehensive instructions to do a Dana 20 rebuild. The factory service manual provides far more detail of the process. However, the information here should give you a good idea what’s involved as far as parts, tools, and some techniques go.