Oh boy, let me go on and on and on about this…sorry…
What normally "breaks" within our “Auto-lock free running hub assembly” (Nissan Part #40250-1S700) is the “Fixed cam assembly”.
I was told that part of it was made of plastic (top left in last pic above^) in order to act as a “fuse” within our front drive; designed to fail saving other more expensive parts (odd that I’ve never had one fail during the many CV axle failures I experienced in the past…but I digress). I always figured it was made of plastic to help quiet it down but WTF do I know....
Anyways, when needing to replace the ““Fixed cam assembly” you will find the part is now called the "Thrust Washer", Nissan Lookup code 40256D, Nissan part number 40218-8B400
At NissanPartsDeal HERE
I'd make sure that's what I needed and check a junkyard first.
Your other option is to find and purchase non-OEM hubs.
I am in total agreement with RacerXXL. My preferred replacement was always a set of old Hard Body Manual Hubs (Nissan Part #40250-S3900)
that are even more difficult to find than our OEM Autos.
I ran them for years before I SAS's my egg crate and the only time I had a problem with them was when the cheap, slightly larger than OEM non Nissan replacement POS Chinese made CV shaft I used caused them to get stuck in "Lock" (the larger "stub-shaft" part of the replacement pushed a gear within the hub out of place, easy fix).
The only time I had to replace them was when the "stub-shaft" part of the cheap non-Nissan replacement POS Chinese made CV shaft, I used blew up inside the hub! (Note to self: don't use cheap non-Nissan replacement POS Chinese made CV shafts).
Hard Body hubs use the same studs as our OEM Autos, an added benefit.
These studs are, IMHO, awesome. If you take notice, we don’t need to use any lock washers when installing our hubs. That’s because these studs “stretch” and then hold. Hence the relatively low torque (18-25 ft-lbs). Most folks over tighten these bolts and/or fail to torque them down evenly causing them to break.
There are two aftermarket brands of Manuals I’ve seen on the trail. WARN and MileMarker. I have not run ether and personally would run OEM Autos if I could find them before using ether.
Both stick out further than OEM so get beat up during any type of rock crawling.
Warn model 29091 (Warn on Amazon
) Manual Hubs have a “common” stud failure that I’ve personally seen. Some folks have tried to avoid that failure using grade 8 bolts and thread-loc however, IMHO, it’s kinda F’d up that you need to modify the studs with a new, out of the box $200+ item…
There could also be two problems you might encounter using those grade 8 bolts.
First is that if they break (never seen it) they would be even harder to tap out of the wheel hub than the supplied WARN studs.
Second is that if they start to back out they destroy your "wheel hub" by “egging out” the holes requiring replacement of that "wheel hub" (I’ve seen this happen and helped fix more than once).
So the trick with WARN hubs would be to be vigilant with your driving not hitting the part of the hub that sticks out and monitoring torque of the studs/bolts so they don’t have a chance to back out. Kind of a pain but better than nutin…I guess.
Mile Marker 6 BOLT, 28 SPLINE HUB Model 435 manuals are also widely available although I care for them even less than WARN. Almost every guy I’ve been on the trail with that ran MileMarker manuals has had at least one explode. I’ve personally seen one blow up on the trail for no apparent reason. I know a lot of folks on the boards never had any problem with them, but I would not use them on my truck.
If I gotta be honest I'd go to a junkyard set of used Nissan auto's before I'd put MM or Warn hubs on my eggcrate...but that's me just sayin’.
Another option could be;
AVM Model 461 Manual, 961 Auto
I've never seen these but was told AVM made the Hard Body Manual Hubs I like so much. I’d research a bit more, but the brand is well respected, and they look beefy.
I’ve seen similar looking hubs on eBay however, IMHO, there’s a lot there I’d be worried about including but not limited to; the Chinese origin, “NOT be responsible for any delay”, prices quoted seldom mentioning include taxes, VAT, or other hidden charges and most of all the "...images are for reference only" statement. Yikes!
I've ran my ARB equipped front on OEM auto hubs and although I've blown through a couple of axles, I've never blown an OEM auto hub.
So to recap my preference; OEM HardBody Manuals (40250-S3900), then our OEM Auto Hub (40250-1S700), if I could not find those I’d try the AVM and then the WARN.
Sorry to drone on, hope it helps.