I wanted to add my first-hand S35 observations for those that are considering one & might stumble onto this thread in the future. There’s no shortage of opinions, educated guesses and flat out speculation about the S35 upgrade that people have to wade through to find the limited amount of first-hand accounts & I remember it well having read it all (now over three years ago) along with most of what’s been written since, & I for one would’ve loved more usage reviews when considering this upgrade but they’re in pretty short supply - so here is what I’ve done, where I’ve done it, & what the results were - the conclusion I’m drawing here is that it will do what I have done with ease.
I bought my 2004 X in late 2016 with the stock Dana 35/Dana 30, 3.07 gearing and 33s; I bought it solely for what it looked like rather than what it could/couldn’t do on or off road.
In the spring of 2017 when I realized I’d be going off road as often as I could I had it re-geared to 4.56 & added the Super35 and Super30 shafts with air lockers. In the 3 years that followed I put 10,000 miles on including over 40 full wheeling excursions ranging from 6 to 8 hours off road (8 when I started, now I’m barely good for 6, this shit beats me up
), each of those days also includes a round-trip of 150-200 highway miles depending on where I’m going.
Trail selections I’ve run are typical Appalachian mountain terrain ranging from dirt roads to mud trails to deep mud trails to water crossings to off camber twisty trails to hill climbs to rocky trails to very rocky trails to trails I had to be dragged through with assistance because lockers weren’t enough to maintain momentum.
I’m generally pretty conservative which I define as: I don’t drive fast, I don’t get things bouncing though there have been exceptions by accident, I crawl by default, if I ever mash a pedal it’s always the clutch to kill torque & stop to rethink what I’m doing, only then do I begin again. If I fail to navigate an obstacle while locked after several attempts I will generally pull the winch line rather than push my axle’s luck.
By far my favorite thing to do is climb hills, the steeper the better, and it can be plain dirt, gravel, coal, a monster boulder, or a tree stump rock infested heavily rutted cluster fuck, when I see an incline my instinct is to crest it. This is no doubt the most stress my S35 sees, all the weight is on it & that’s most often where the axle is also locked so it’s really seeing the worst of circumstances from a stress standpoint that I throw at it. I generally prefer to try most things open at least once or more before resorting to the locker, just more fun that way but I know the areas where I go off road well enough at this point that I know where to lock first; often when I’m doing these climbs the locker ends up on at one point or another.
I’m not a big rock garden guy, I shy away from them, not because of any limitations of my rig but because I don’t find any joy in it. I’ve done my fair share of them particularly in my first two years when I wanted to try everything & I was still experimenting. I banged everything up pretty good underneath doing it, particularly my diff housings, control arm & rear shock mounts, tie rod & gas tank skid/trailer hitch. If I never hit any of those things again I wouldn’t be pissed. I’ve also done a fair amount of other damage, both front fenders, passenger side door/door jamb, two sets of flares & so forth, all of that was done while doing/attempting to do something sketchy & usually in a really awkward positions.
My TJ is as light as it can be, it’s weighed down by bigger tires, some skids underneath and a winch up front but other than that I think it’s about as lean as I can get away with & still be competent (I carry a tool box @80lbs full in lieu of a back seat and a spare on the stock carrier with a stock rear bumper). I also run a soft top year round & no other superfluous bling is affixed in or on my rig. I’m light at 140lbs & generally riding solo. All my trips are day trips so there’s no camping equipment or anything else, just me, the tools & a bag with a couple candy bars & water bottles is about it. It’s also doorless around 7 months of the year.
That’s it, that’s the story of what my Super/35 & Super/30 axles have endured without mechanical failure, breakage or damage of any kind; I removed the rear cover yesterday and everything looks brand new. The only issue I had was maybe a few months after install my rear pinion seal leaked & the shop that installed the gears put a new one in gratis. Other than that they’ve run quiet and smooth.
Those are my observations, make of them what you will.
One editorial comment, given my experience with these axles I do believe they are overbuilt for my purposes, I don’t think I’ve approached the limit of abuse they can handle. It’s a moot point however because I believe they’re still necessary given that the only step down would’ve been to leave them stock & open which simply wouldn’t have served my purposes – I have unequivocally needed my lockers too many times to have been able to go where I’ve gone & had the fun I’ve had without them, and while I can’t say for sure I probably would’ve broken at least one stock shaft by now doing some of the things I’ve done, particularly in my first year when I was much less experienced behind the wheel.
Gears look as good as the day they were installed:
I bought my 2004 X in late 2016 with the stock Dana 35/Dana 30, 3.07 gearing and 33s; I bought it solely for what it looked like rather than what it could/couldn’t do on or off road.
In the spring of 2017 when I realized I’d be going off road as often as I could I had it re-geared to 4.56 & added the Super35 and Super30 shafts with air lockers. In the 3 years that followed I put 10,000 miles on including over 40 full wheeling excursions ranging from 6 to 8 hours off road (8 when I started, now I’m barely good for 6, this shit beats me up
), each of those days also includes a round-trip of 150-200 highway miles depending on where I’m going.Trail selections I’ve run are typical Appalachian mountain terrain ranging from dirt roads to mud trails to deep mud trails to water crossings to off camber twisty trails to hill climbs to rocky trails to very rocky trails to trails I had to be dragged through with assistance because lockers weren’t enough to maintain momentum.
I’m generally pretty conservative which I define as: I don’t drive fast, I don’t get things bouncing though there have been exceptions by accident, I crawl by default, if I ever mash a pedal it’s always the clutch to kill torque & stop to rethink what I’m doing, only then do I begin again. If I fail to navigate an obstacle while locked after several attempts I will generally pull the winch line rather than push my axle’s luck.
By far my favorite thing to do is climb hills, the steeper the better, and it can be plain dirt, gravel, coal, a monster boulder, or a tree stump rock infested heavily rutted cluster fuck, when I see an incline my instinct is to crest it. This is no doubt the most stress my S35 sees, all the weight is on it & that’s most often where the axle is also locked so it’s really seeing the worst of circumstances from a stress standpoint that I throw at it. I generally prefer to try most things open at least once or more before resorting to the locker, just more fun that way but I know the areas where I go off road well enough at this point that I know where to lock first; often when I’m doing these climbs the locker ends up on at one point or another.
I’m not a big rock garden guy, I shy away from them, not because of any limitations of my rig but because I don’t find any joy in it. I’ve done my fair share of them particularly in my first two years when I wanted to try everything & I was still experimenting. I banged everything up pretty good underneath doing it, particularly my diff housings, control arm & rear shock mounts, tie rod & gas tank skid/trailer hitch. If I never hit any of those things again I wouldn’t be pissed. I’ve also done a fair amount of other damage, both front fenders, passenger side door/door jamb, two sets of flares & so forth, all of that was done while doing/attempting to do something sketchy & usually in a really awkward positions.
My TJ is as light as it can be, it’s weighed down by bigger tires, some skids underneath and a winch up front but other than that I think it’s about as lean as I can get away with & still be competent (I carry a tool box @80lbs full in lieu of a back seat and a spare on the stock carrier with a stock rear bumper). I also run a soft top year round & no other superfluous bling is affixed in or on my rig. I’m light at 140lbs & generally riding solo. All my trips are day trips so there’s no camping equipment or anything else, just me, the tools & a bag with a couple candy bars & water bottles is about it. It’s also doorless around 7 months of the year.
That’s it, that’s the story of what my Super/35 & Super/30 axles have endured without mechanical failure, breakage or damage of any kind; I removed the rear cover yesterday and everything looks brand new. The only issue I had was maybe a few months after install my rear pinion seal leaked & the shop that installed the gears put a new one in gratis. Other than that they’ve run quiet and smooth.
Those are my observations, make of them what you will.
One editorial comment, given my experience with these axles I do believe they are overbuilt for my purposes, I don’t think I’ve approached the limit of abuse they can handle. It’s a moot point however because I believe they’re still necessary given that the only step down would’ve been to leave them stock & open which simply wouldn’t have served my purposes – I have unequivocally needed my lockers too many times to have been able to go where I’ve gone & had the fun I’ve had without them, and while I can’t say for sure I probably would’ve broken at least one stock shaft by now doing some of the things I’ve done, particularly in my first year when I was much less experienced behind the wheel.
Gears look as good as the day they were installed:
The C-clip eliminator option too.
