So you’ve worked hard on restoring your Jeep; you want to show it off. However, most classic Jeeps have one major problem… their gearing doesn’t allow them to reach highway speeds. For many Jeep owners this can be frustrating. You want to be able to take it out regularly – maybe to shows, maybe just recreationally – but, not being able to reach highway speeds can be limiting.
installing an overdrive
This is why I’ve always been a advocate of the driveability factor – sure some modifications might make your Jeep a little less “authentic” – but I say, if it adds to your enjoyment you should go ahead and do it! I think that adding an aftermarket over-drive is essential to improving your Jeep’s driveability.
Unmodified, the smaller 4-cylinder Jeeps top out at 40mph, while the wagons and trucks with a 6-cylinder can reach 50. Adding an overdrive reduces your RMPs by about 25%. This allows 4-cylinders to reach 50mph and 6-cylinders to reach 60mph in 3rd gear.
Aftermarket Jeep overdrives bolt directly to the transfer case and require no other drive-line modifications, making it a relatively easy install. Doing it yourself, most people can install one in just a few hours. Also making the overdrive the most practical way of improving your Jeep’s driveability.
If you decide to add an overdrive, it is important that you look for quality parts made in the USA. Fully synchronized overdrives with a separate shifter are best, because they can be used in any gear, even in 4WD.
overdrive completely installed on transfer case
This acts as an additional gear in-between each gear. This makes them great on hilly terrain, like here in Pennsylvania and also great for tackling off-road obstacles.
In our next post, I’ll show you how to get the right fit for your Jeep model and demonstrate the installation.
