Let me preface this by stating once again that I am not a mechanic or and engineer. I take my 2001 Xterra off-road and work on it now and then.
That said a word or two about “BOLT-HUB, FREE RUNNING”, Nissan part # 40254-32G00, in relation to my Xterra…
These are the six bolts holding the Auto-lock free-running hub assembly or Manual-lock free-running hub-sub assembly to the Wheel-hub. See diagram from the FSM below;
These are mine holding my Nissan Hard Body Manuals in place;
There is no reason for these to break or for me to replace them with a stronger grade bolt (I can get into this if you’d like).
There are two reasons they break; neglect and/or ignorance. I try not to neglect my truck but have broken more than my share of these bolts and am writing this with the hope of saving you from repeating my past ignorant mistakes.
If these bolts have never been off of my 2000-2004 truck to repack the wheel bearings I have neglected them (and my bearings). My now rust-welded bolt could break when I finally got around to this necessary bit of maintenance or need to replace my toasted bearings.
These bolts are not “Grade 8” bolts, not even close.
Like my
Wheel-Studs they “give” a bit (this is why I don’t need a lock washer or nut to secure them) however they are even weaker (only torque 18-25 ft-lb, wheel-stud 87 - 108 ft-lb).
Like my wheel-stud I need to torque them properly for them to work as intended.
If I torque them down too much I can stretch them out (weakening them) or break them.
If I don’t torque them down enough they can back out.
If I don’t torque down each bolt to the same proper spec I risk stretching or breaking a bolt by putting more stress on the one or two tightened correctly rather than spreading it out evenly among the six as intended.
If I don’t clean the bolt and its receiving hole in the wheel-hub it might cross-thread or gets stuck on a chunk of thread-lock residue and break as I try to get it to seat.
Yes I said "receiving hole"...very funny. What would you call it?
If I still break one this;
Snap-On (Blue Point) Extractor Set, 20 pcs.…is the only tool that has worked when I’ve attempted to extract the broken bolt from the wheel hub. I think “Astro” makes a less expensive version but I’ve never used it.
I’ve replaced two of my wheel-hubs to date breaking two other types of extractors in each.
IMHO the reason this tool works well in this application is that the drill guide fits perfectly inside the wheel-hub centering the bit perfectly on the broken bolt and preventing it from “running” as I drill. And I can turn broken bolts using high torque without the extractor expanding the bolt.
Hope this crap helps somebody...