60Bubba Posted October 11, 2015 Share Posted October 11, 2015 I'm pulling apart the axles for new gears in the CJ, and I thought I'd upgrade my lockout hubs while I was at it. Seems like the options are limited for the 5 bolt hubs. I read some posts indicating swapping the bolts for studs with nuts was a good way to ensure they didn't loosen. Any thoughts? Anyone know what size studs I'm looking for? I believe the hole is 3/8 coarse, but I don't know how long or what threads I need on the nut end. Alternately, is it worth swapping the wheel hubs to the older 6 bolt version and opening up my options for locking hubs? Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted October 11, 2015 Administrators Share Posted October 11, 2015 60Bubba...You can swap the wheel hubs to 6-bolt type and many do. Hub depth and wheel bearing spacing is the only concern. Compare wheel bearing part numbers for each of these designs. Compare spindle diameter and the spindle part numbers. If they match up, the swap is practical if you can justify the cost of new hubs. If the wheel bearings have high mileage, this is the time to change out the wheel bearings and pack the new bearings properly, too! Install new inner seals. (Some hubs come with bearing kits and the races/cups installed.) Make sure bearings are Timken or equivalent (SKF, Federal, etc.) quality. Moses Quote Link to comment Share on other sites More sharing options...
60Bubba Posted October 12, 2015 Author Share Posted October 12, 2015 Been thinking the same thing about the six hole hubs. Are you familiar with the trick of changing the lockout hub bolts to studs and nylock nuts to prevent them from backing out? I can't see why just using the bolts with some blue lock-tite wouldn't work, but apparently lots of folks take the time to switch to studs. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted October 18, 2015 Administrators Share Posted October 18, 2015 Case...Studs make better sense because you have thread sets at each end to compensate for elongation. Studs have less tendency to rock or loosen like the OE bolts. Visualize: The free-wheeling hub actually drives the wheel hub (axle shaft splined to the free-wheeling hub, not to the steel wheel hub). Torque on the outer/hub meets resistance at the steel wheel hub and rotor. This side-loads the bolts, which want to rock, loosen and stress the steel wheel hub threads. Studs with outer nuts also act more effectively as a clamping force. The hard (typically Grade 8) studs want to resist without yielding, thus reducing movement. Two sets of threads per stud also mean less tendency to wear or stress the steel hub's threads. Studs can be set with Loctite Red (271 or equivalent) and will not move around in the steel hub threads. This behaves more like a solid joint. Overloaded threads will pull loose. With a stud, you distribute load over two thread sets. The studs drive the hub with more uniform force. Of course, all of this is dependent upon proper tightening and maintaining sufficient, uniform torque on each of the nuts and studs. Quality studs being Grade 8, they have less ductility and resist flexing. As a footnote, studs are also prone to shearing rather than yielding when side loads exceed their torque limit! Grade 5 or even 6 will yield slightly, which suggests why winch mounting bolts are often Grade 5 rather than 8: Despite less overall tensile strength, Grade 5 is more ductile and will yield more before shearing. Of course, a Grade 5 bolt is not as "strong" as a Grade 8, you always replace OE Grade 8 hardware with Grade 8. The real issue here is lack of fastening points, 5 is less than 6, and 6 is geometrically superior: two triangles, and triangles are the strongest basic geometric design in Nature. Given that the bolt thread or stud diameter is the same for 5- or 6-bolt Jeep CJ hubs, 6-bolt stamina will always be better than a five-bolt configuration. However, the real troubles begin with oversized tires, heavy torque loads and loosening bolts. Once loose to any degree, five-bolt hubs will pull threads and create havoc. Note: Bendable lock tabs are the traditional securing method; replacing lock tabs with split ring lock washers (regardless of grade) is a large mistake. The lock rings will also chew up the soft alloy free-wheeling hub flange, which results in loosening bolts...Wire-tying these bolts is not overkill, many at-risk fastener situations use wire-tying as a remedy. Again, there is even a price incentive for going to 6-bolt hubs, they usually cost less. You need to match up the bearing/spindle relationship to make sure the 6-bolt hubs will fit. You'll need to follow your rotor thickness and be sure the caliper aligns with the rotor properly. If you need to do rotor or wheel bearing work, that would be the time to consider the 6-bolt hub and free-wheeling hub change. It's actually straightforward. As a final note, I have learned a lot from OE engineering. The most failsafe method for attaching a critical, loaded piece like an OE bolt-on steering arm on a heavier duty truck axle is to use tapered seats at the top of the arm, hardened (Grade 8 typically) studs into the steering knuckle and split conical/tapered bushings beneath self-locking nuts. This covers all bases: The hard stud is secured to the knuckle threads, the arm cannot loosen or shift because of the wedging force of nuts against the split conical bushings, and the high-tensile, self-locking nuts on fine (SAE) outer threads wants to stay secure. Nothing shifts, moves or loosens. I've worked on live (beam) front axle G.M. and other one-ton and larger rated trucks that use this steering arm-to-knuckle attachment method; you can sweat profusely trying to remove one of these arm and bushing sets after years in service. If you do go to studs on your 5-bolt arrangement, make sure the outer thread is SAE, which is stronger and less likely to loosen in service. I use "Toplock" or equivalent Grade-8 all steel nuts. They are self-locking (pinched at outer threads) and do not have issues with heat and the elements like nylon insert or "aircraft" nuts. Toplock nuts are used in industry, aviation, farm and construction equipment and in automotive applications. Like nylon insert nuts, steel top lock types are typically expected to be a one-time use then replaced during service work. Moses Quote Link to comment Share on other sites More sharing options...
60Bubba Posted October 19, 2015 Author Share Posted October 19, 2015 Moses, As always, thanks for the in-depth analysis. I'm still deciding whether or not to attempt the six-bolt upgrade at this time. The overall cost of the re-gearing project is growing, so I may settle for studs and top-lock nuts as directed. I appreciate the feed back on that issue, as many others just go with nylock nuts. It seems very logical to avoid the plastic inserts given the heat and elements those nuts will be exposed to, but I would probably not have thought of it on my own. I did use top lock nuts on my shock towers during the rebuild, so I know they are very effective. Whatever decision I make, I'll try to get some pictures during the process. Quote Link to comment Share on other sites More sharing options...
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