Nuts & Bolts: Dodgy Hubs
A reader asks about the advantages of a Dynatrac Free-Spin Kit. He owns a 2011 Dodge 3500.
I have a 2011 Dodge 3500 with a manual transmission similar to Fred William’s white truck. I noticed his has locking front hubs; is this the conversion from Dynatrac? What are the advantages? I am thinking of doing that. I also have a 1983 Jeep J10 with a six-cylinder and four-speed transmission. The gears get out of sync, and the gear dogs jam. How expensive is that to repair, and is there another transmission and year that would swap in?
Williams’ Dodge is equipped with a Dynatrac Free-Spin Kit. The main advantages to the kit are serviceable wheel bearings and the ability to disengage the wheel hubs from the rest of the axle assembly, which reduces drag as well as wear and tear and improves fuel economy. For many years now, most truck manufacturers have used unitized wheel bearing assemblies on the front axle. These bearings are not serviceable and are in theory good for the life of the vehicle. In reality, however, it is well known that this is not the case, especially in the case of 3/4- and 1-ton trucks that are frequently used to haul heavy loads. As for Dodge trucks, the axleshafts are also attached to the unit bearings, which mean they spin all the time, even when the truck is in two-wheel drive. Replacement unit bearings are extremely expensive. The cost of a Free-Spin Kit is often close to the cost of a pair of replacement unit bearings. Servicing the bearings of a Free-Spin kit is just like servicing any “normal” hub assembly, so with regular maintenance they can easily last for the life of the vehicle. The locking hub enables the axleshafts to be disconnected from the hubs, which reduces drag as well as wear and tear. If you plan to keep your Dodge for many years, one of Dynatrac’s Free-Spin kits would be a wise investment.
As for the transmission in your Jeep, if it has an unsynchronized First gear, then it is likely a T-18. If it has a synchronized First gear, then it is probably a T-177 or T-178. These are all decent transmissions, though the T-18 is the stronger and more desirable. Diagnosis is difficult without our actually seeing the transmission, but it sounds like it’s getting stuck in gear. The first thing we would do is drain the tranny and pull the top cover of the transmission to have a look inside. If there is something wrong with the gears themselves, then it should be pretty obvious. If all appears to be well, then the issue is likely in the top cover or shift forks. A bent shift fork could be causing the issues you describe, as could a worn shift mechanism. Both can be difficult to detect without experience, but neither should be terribly expensive to fix at the right shop. We recommend taking it to a knowledgeable shop for repair, as not every shop is going to have techs with the experience to diagnose and repair one properly. Regardless of which transmission it has, it’s worth fixing rather than swapping.