How to destroy your front drive train and ruin 2 group trips

TLDR:
Don't shock load your drive train
If you have RCVs really, really don't shock load your drive train.
RCVs + shock loading = damage to shit you can't see
Shock load damage doesn't always manifest in immediate catastrophic failure, always assume shock loading strips the life from your drive train components.

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I don't maintain my build page anymore so here are the main mods that matter for this:
RCVs
37s
tacobox
Rockjock60
dual locked

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If you want to take a break from all the coronavirus bullshit and learn how I got to this

and then later this

please continue reading.......

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I've posted a couple pics here and there of the damage but never really gave a whole lot of explanation of what happened in what sequence or why, the only person that knows the whole thing from start to finish is me, several people saw a couple parts of it first hand but I'm the only one that dealt with all the bullshit and has had time to reflect on everything that happened. I didn't take photos of everything, I was debating even posting anything about the carnage but in the interest of educating people I figured I'd share. I know some clowns will misread what I'm saying or make false assumptions about some aspects of the events but I figure some people will actually learn something from the shit show I made out of my own stupidity and ego.

July 11, 2019
Ran the Rubicon for our first time with @theesotericone, we were under a time crunch with a jeep event starting over the weekend so we ended up starting the trail at 6AM on a Thursday and finished the technical part at around 2PM and that was after getting stuck behind some crawlers with trailers and locker issues. We basically smoked the thing and got to thinking, well if we did this and it wasn't too bad we should try Fordyce next but probably wouldn't be able to set it up with work schedules and husbandly duties.



September 21, 2019
Stars aligned, work schedules aligned and dam maintenance dropped the water flows to lower than the Sierra Trek water flows. @theesotericone contacts me a couple days before and asks if I want to go and we set it up for the weekend.

I tool around a lot on here and IG looking around learning as much as possible and I knew the following going into the trail.
1) I knew that I had never broken anything on a crawling trail. (the Death Valley incident wasn't a crawling trail ) A couple dented drive shafts here and there but I always got off every trail under my own power and was able to drive home under my own power.
2) I had never seen anyone break a front R&P or a carrier
3) I have only seen 1 report of a person breaking an ADD shaft/tube, which appeared to be a freak occurrence or manufacturing issue with the shaft that allowed it to break instead of the passenger CV
4) with RCVs and a rear D60 my drive train was pretty bullet proof with a shitty low power toyota motor (or so I thought)

So we hit the trail at 7AM and everything until you start hitting the Winch Hills is pretty chill, once you hit Winch Hill #1 the trail starts to get dramatically harder and the difficulty escalates and peaks at around Winch Hill #4. We make our way though and I can't recall exactly where it was, whether after Winch Hill #3 or Winch Hill #4, but there was a rock garden and it just had the perfect combination of big ass rocks, incline and mud pit at the bottom that made it impossible to get passed the middle of the rock garden. I had taken every hard line I could take up until that point and didn't have to winch yet. I was determined to get through the trail without winching. How cool would it be to be able to say that I had done Fordyce in a street legal IFS piece of shit and didn't have to winch? so I then proceeded to beat the shit out of my drive train trying to get up this rock garden without winching. First it started off gently trying to find a way to get up with smooth slow tire spin, which then over the course of 20+ minutes descended into me hopping my tires trying to get up through the rocks. Here's a couple videos of the area before I started hopping my tires like a retard. They aren't particularly interesting and one of them is kind of long with me just making attempt after attempt slowly spinning tires. Only @theesotericone can testify to how stupid I went after he stopped recording. I should have stopped after the first couple tires and just winched but my ego got the best of me.





After these Matt stopped filming, IIRC I switched out of compound low and started getting stupid trying to bump up and hop up.....none of it worked. Here's after I admitted defeat after fucking around for way too long.


So we make it through the rest of the trail, I think after everything was said and done @theesotericone winched 3 times and I winched 3 times and got strapped once after high centering on some rocks. Matt blew 3 beads and I got some passenger side body damage on Winch Hill #1, also I bent my front bumper so bad on the passenger side we had to do trail surgery on it so it wouldn't slice the tire open at bump. Fordyce took us around 10+ hours to run, we started at 7AM and set up camp near the lake at the end some time between 5PM and 6PM. We were pretty beat up after the trail so the next day we drove back on the 395 so if we had any issues we could deal with them before we got to Bishop. We both got home with zero issues. Prep work for Dusy-Ershim started after the return.

Couple Fordyce videos...









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Before moving on to Dusy, We'll take a step back and look at a deficiency that will only affect a small portion of people who offroad. I have always looked at the gap between the rear of the slider and the rear tire and thought some day that is going to fuck me and something is going to get caught in there. I don't know why fab shops don't run the slider all the way back close to the tire, maybe shipping costs increase over a certain length? I don't know, its a shitty design though.

Comically, after the next incidents, someone on TW was asking about that very issue and a bunch of people piled on him saying that it would never be an issue and it was stupid to be complaining about it.
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September 30, 2019
So the goal for the year was to run Norcal's big 3 in a single year. We already did Rubicon and Fordyce, next was Dusy Ershim, took care of a couple things the week between and returned to Norcal for Dusy. Up until this point I had been able to claim that I had never catastrophically broken something on a crawling trail and I had finished every trail I started and I lost both of those claims on Dusy. First up, on an odd ball break over angle obstacle I was fucking around trying to take an outside line and heard a loud pop out of my front end and saw my tire go the opposite way that I was turning. I jumped out of the truck to check and make sure it was the tie rod, and sure as shit it had bent and broken off. I was able to back off the obstacle and get to a flat spot and started to tear the tie rod off when Steve asks if I had the other part that broke. I noticed something was off about the failure but it didn't dawn on me since I was in such a rush to get the thing changed out that when he said it I finally put it together that the long travel tie rod extension broke along with the inner bending. I was fucked without a spare. Luckily we had battery welding kits available and Steve butt welded it together and we added some wrenches for extra weld. We had some issues with getting the right amperage, my 2 batteries wasn't enough to keep the arc going and 3 batteries was too hot. Had to deal with it being too hot and got everything stuck together.

We continued on the trail until we got to an area where @Mike likes Tacos was having some trouble. Seems his wheel base was fucking him and he kept sliding laterally on a small hill in some loose dirt, he gave it several tries and couldn't make it, he then tried a different line and ended up crushing his driver side fender so he ended up back on the original line and just smashed the gas pedal. Watch closely and you can see his driver side rear tire hit the tree as he gasses up the small hill.



So my ego gets the best of me again (this seems to be a recurring issue with me ) and I figure fuck it, I'm on 37s with a crawl box, I've got this shit. So I proceed to try to slowly spin my way up and after 2 or 3 minutes my truck freezes in place. All my tires are spinning and there's nothing under the truck to get hung up on....but something grabbed my truck and is holding it in place and then it hits me.....The fucking tree in the middle of the trail and that giant ass gap in my sliders.....it finally happened........ The perfect tree, the perfect gap, the perfect off camber slippery hill, and the perfect lateral slide.

So now I'm fucked. I'm worried about breaking the rear driver side axle, all the tires are spinning fine, but the rear driver side has a the most resistance on it. So I put it in reverse and try to get the tree to pop back out and slide along the taper of the slider. I slowly started to try to rock the steering back and forth to get the truck free but it wouldn't go. Not shock loading or smashing the gas pedal, just slow smooth tire spin..... and then we hear a loud bang out of the front end. It was loud enough that @theesotericone was behind me and heard it over music in his cab. I figured the patch job on the tie rod failed and gave out, I hopped out of the truck and checked but it was fine, I checked everything else but everything looked good. I jumped back in the truck and try to start moving and @theesotericone tells me I've got oil pissing out from somewhere near my front diff. In the back of my head at this point I'm racing trying to figure out what it could be, and I keep recalling the report of the broken ADD, but keep thinking naw, naw naw, I've only seen 1 report of that happening it can't be. I try spinning the drive train but its bad, there is a bunch of crunching coming from the front end and we call it quits on trying to drive it out. After that we pulled all the air out of the stuck tire and ended up setting up 2 winches. We tried it with 1 winch but it wasn't enough to pull my truck sideways. We had 1 snatch blocked off the front of the slider and the other snatch blocked to the rear bumper and pulled the truck side ways. After we freed it up we reseated the bead on the rear tire and winched my truck up to a flat area.


After getting it on flat ground and seeing exactly where the oil was coming from I was pretty certain it was the ADD. Got the skid pulled and yeah....it was the ADD.




See those cracks in the housing? Those are 2 separate breaks on opposite sides. When the ADD shaft sheared it had so much force it punched holes out on both sides of the housing. The shifter fork was broken and the pieces of the shaft had additional cracks.

Now it was decision time on how to get me back off the trail. Originally we were thinking that We would be able to put things back together and I could use 3 wheel drive but while I was stripping things out I realized the the ADD tube was almost completely sheared in half and if it broke in half on the 6 miles back to the trail head the differential housing would only be supported by 2 points and would likely start to violently flop around. For anyone wondering how that would work, the diff assembly is held in place by 3 points. 1 on the rear of the diff housing, 1 on the front of the diff housing and 1 on the outboard end of the ADD housing. If my ADD housing severed down the middle I would have lost the outboard passenger side mount and would have allowed the driveshaft and driver side CV to potentially flop the broken assembly around damaging other components. Made the decision there to pull the entire front drive train out plug the front bearings with just birfield cups and drive out in 2 low.

We returned the 6 miles back to the trailhead with minimal issues, had to winch and strap 3 or 4 times. We set it up so that @theesotericone was in front of me running the trail as much as he could in 2LO, so that when he had issues I knew I would have to at least gas it to get through, it saved me getting stuck a couple times knowing when I was going to have problems.

After that the group fell apart @theesotericone headed home and @Mike likes Tacos got PTSD from the break down and refuses to offroad with me anymore

Also that was the end of my bragging rights of never having a break down on a crawling trail or having to be escorted or towed off in my truck.

October 1 - November 15 2019
After blowing up the ADD I figured it was time to do the full mechanical 4WD conversion. I replaced the front ADD with the FJ tube swap and picked up a junk yard FJ transfer case and swapped everything out. Everything went OK except for finding this crack that was going to eventually fuck me. This is the rear mount for the differential housing, apparently years of gross abuse takes its toll. I just ran a bead over the crack and ground it back down smooth to repair it.


Over the several weeks I did all the work and reinstalled everything. One critical thing that will play a part in the next shit show was that I inspected all of the teeth in the front differential. I was afraid that the shock loading that I subjected the truck to on Fordyce not only fucked up the ADD but also the R&P. I checked all the teeth through the fill/drain ports and everything looked fine and I put everything back together

November 16, 2019
@Tacoma1192 and I had a trip to Moab in a couple weeks so we needed to get a test run in before to test out his 4 link and the drive train components I swapped out. We headed up to Stoddard Wells and did my rock crawling loop I have out there. On the way up I had some weird humming/vibration coming from somewhere but I couldn't figured out the source. When we aired down I searched around and the only thing I could find was a slightly loose bolt somewhere on a skid plate. Here is a short video of some sweet 4 link action.



After we finished up, the noise was still there, most obvious around 35-55mph with changes depending on steering angle. I looked for it afterwards but still couldn't find the source, thought maybe I had a ujoint going out or maybe the junk yard transfer case was no good or I fucked up the 2 stick conversion for it. Everything was fine other than the hum so I said fuck it, its good for Moab.

November 25, 2019
Drive up to Moab was fucked up, there was a snow storm rolling through Utah and I ended up crusing through the snowy mountains and hi desert areas in 4HI at 40mph+ some places topping out at 60mph occasionally. Went on for this for over 150 miles. Still had the same weird hum when in 2WD at lower speeds but it was uneventful outside of that. Once I got to Moab I had some weird shit happen pulling into the self serve gas station on the north end. When I went to pull in I had some weird quick popping/grinding/clunk noises coming from the front end making the sharp turn into and out of the station, I figured it was just the tires grabbing on the asphalt since I was still in 4HI and there were areas that weren't covered in ice/snow so I didn't think much of it.

November 26, 2019
I don't have any photos of the next shit show so just read along. This also happened several months ago so my memory might be a bit foggy on the what, when and why as I was trying to unfuck myself out of the ditch.

Next morning I wake up late and go grab some Wendy's and as I'm driving down Main Street stuffing fries in my face I hear a catastrophic loud bang in the front end, the truck jerks to the side for a second, then continues rolling normally. I borderline shit myself but figure since it so quickly went back to normal that maybe a giant chunk of ice in the wheel well broke free, got jammed in the wheel well against the tire and the broke into pieces and everything was now good.

A couple miles later I get to a icey up hill area and I try to put the truck in 4HI but I start to get a bunch of grindy crunchy noises, take it immediately back to 2HI, continue on to my destination and try it 2 more times but the same thing happens. I keep thinking its the transfer case because its having issues shifting around. Finally I get to the dirt road I'm going to cruise out along and decide its time to figure out what the fuck exactly is going. At this point I'm starting to think its the diff so I put it in 4HI and it all happens the same again, this time I leave it in 4HI long enough and the truck starts to slide uncontrollably along the ice into the ditch on the side of the road. Get back out of the ditch in 2HI and finally stick my head out of the window while I go into 4HI again and sure as shit the front locks up but instead sliding into a small ditch, now I slid into a ditch with 18+inches of snow that I can't get out of because the front end is locked up.

At this point I'm pretty fucked, the differential is broken and locked up. I can't turn the tires due to the front locked, air down, stuck in a ditch. I can't really move in 4HI with the front locked and I can't get traction in 2HI. I had no idea when someone would drive by that would be able to pull me out and even if they had a capable vehicle I don't know if it would have been possible with the front tires locked at an angle facing away from the road. I came up with the genius idea that, since my R&P was fucked, and the carrier was probably fucked, so if I put the transfer cases into compound 4LO I might be able to break my way through the tooth jam. Well it worked, and after some horrible crunching, popping, and grinding I was able to get out of the ditch, I pulled back onto the road and proceeded to strip out the CVs. Without the CVs in there I could drive back down to Moab. I called @Tacoma1192 and told him my diff was fucked, he said he would bring his extra diff and see if we could get something together so I could at least get 4WD back.

In the interest of getting back 4WD I drove back down to the Maverick station in Moab that has a nice big lot and proceeded to strip out my front drive train yet again in the last couple months to figure out how much damage there was and if it was going to be possible to swap some parts around but it turned into a shit show, there was too much damage and there was a lot fucked up. First thing I noticed was this......

ADD mount is good.
front Diff mount.....

Yeah...I don't know if it was the initial catastrophic bang that did that or if it was the compound-4LO-crunch-through-the-tooth-jam but the front diff mount was bent.

Then the good stuff, apparently crunching your way through the gear teeth ruins them


The pinion is stuck in there. I later tried to get it out multiple ways with a press but that fucker wouldn't come out it. The rear diff mount appeared to be bent too. When I tore everything apart I found the ring gear bolts were all loose and thought maybe there was an install issue, however the next day I found the crowning achievement of my stupidity. A cracked front ARB carrier! This was likely the cause of the bolts loosening up, even properly torqued and threadlocked bolts wont hold properly on broken shit


After the front differential was destroyed I decided I needed to check the rear diff to make sure it wasn't going to fail on the way back to California and found there was some fucked up shit back there too. A year before I replaced the bad bonded seal in my carrier. I decided I needed to learn how to pull and install the carrier with trail tools in the event I had to do it on the trail so that's how I did it in my garage. I thought I got the shims seated all the way in there but maybe I didn't. I don't know if this was just cumulative shifting around over the course of the year or if this was a result of them worming their way out of position as the rear axle housing flexed while I was shock loading it, but yeah, this wasn't good either. I drove home like that, the gear teeth weren't great looking but they probably could have be continued to be used if I hadn't regeared.


After the diff failed it pretty much fucked the trip, we were planning on trying to run some harder trails with his cousin and was going to attempt Pritchett Canyon, but that whole thing went to shit obviously.

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So now how do all of these things tie together? The shock loading that I put my truck through on Fordyce damaged the carrier and the ADD shaft which later manifested in catastrophic failures. That was the first time I had ever shock loaded my truck and it will be the last.

After all this was said and done I started doing research on drive train component failures and figured out that my ADD shaft and been cracked and damaged prior to its catastrophic failure due to the presence of beach marks along the fracture. Its no coincidence that the week before it failed I was going full retard on it.

Recap the events how I think they went down
-No crawling trail failures ever
-Run Fordyce and shock load the fuck out of the truck. unknowingly cracked the carrier and the ADD shaft
-drive home and the next week to dusy and ring gear bolts are starting to loosen up but aren't backed out enough to give any indication
-Run Dusy and the ADD completely fails while slowly spinning tires gently
-ADD shaft shows evidence of prior damage
-drive back home without the front drive train
-inspect differential teeth from fill/drain port, teeth look good. Install FJ tube and case. FJ tube install exacerbates the cracked carrier and accelerates the ring gear bolt noise and loosens them more/faster during test run
-periodic weird humming on the way to Moab with 150+ miles of driving in snow in 4HI, bolts continue loosening up
-diff fails in moab driving down main street the next day
-drive back home from moab without front diff and no humming noise

Lessons learned after everything:
Don't shock load your drive train, ever, if you can manage it. If I hadn't gone full retard on Fordyce I'm confident that none of this shit wouldn't have happened. I got lucky that my front end made it through the snowy mountains while I was hauling ass, if it had locked up through the mountains I most likely would have sailed off the side of the road and killed myself and my dog in the process. RCVs aren't a license to be an idiot, the diff is still only 8".

 

I'm going to read this later but DAYUM!!!!!

 

Holy god. I still find all of this comically entertaining.

 

We want thigh gaps NOT slider gaps!!

 

That has not gone well.

 

I think of a CV axle as somewhat of a 'fuse,' for lack of a better term. Do you think the outcome would have been different with regular CV shafts?


EDIT: Also, great pics! mmmmmm...carnage.

 

I was wondering this as well. Not to be the Monday morning QB, just legitimately curious.

I know the OP wheels the absolute fuck out of his truck and I’ve always dug his build. Here’s hoping the truck gets back on the trail soon.

 

Jesus christ!!! you're a warrior sir!!!
One day I'll get at your level!! Idk about hitting up the Rubicon though......

 

Yes - the axles would have kept breaking saving the rest of the drive train from @tetten dumb ass from shock loading everything. When he first put in the RCV's we went out to Stoddard and I watched him lay into the front end pretty hard. I just sat back and cringed. Then all of this happened with in a year afterwards. OEM CV's are plenty strong as long as you do not shock load - along with the rest of the drive train. Whole moral of the story here. We should all take a moment and appreciate the life lesson @tetten has taught us all - and the $10K he has spent teaching us this.

 

Thats kinda what I was thinking - with the extra torque from the crawl boxes, and the big tires, and the lower gears, and upgraded CVs, the ADD is the obvious weak point.

I really appreciate that he's willing to show us this, its hard to learn when everyone hides their problems. Maybe we can all chip in to a D60 fund.

 

talk about multiple stars aligning. holy crap!





so what's the plan with the truck now?

 

Being there for some of the carnage and a whole bunch of other trails last summer with @tetten I can safely say shit happens. Everyone breaks if you wheel hard. When your time comes you just deal with it.

I think it's unfair to blame Fordyce. The Rubi played a part, as well as Coyote, Mirror, Swamp, Slick Rock and the rest of last summers tick list. You pay to play bro. You just had to pay a little more then most of us. lol

 

40s

 

Most likely, the CVs should fail long before the ADD or the R&P. I was bouncing the truck under the beliefs that since the front tires aren't under as much load as the rear on an incline and I'd never seen someone break a front R&P and only 1 ADD shaft failure I should be OK with some bouncing and abuse. That turned out to be grossly wrong.

 

Impressed by your mechanical skills. Just made a note to self to never by a used vehicle from you.

 

So shock loading the drive train is what it’s called when the truck starts to bounce a little?

 

Bouncing a little would probably be unlikely to cause any significant damage over the short term, the videos I posted of the rock garden didn't show when I was going full retard, @theesotericone stopped filming before I got to that point, but he can testify to how stupid I was being.



This is more geared towards commercial applications but the principals are the same. If someone is bouncing their vehicle aggressively on an obstacle enough that the suspension is being unloaded it momentarily allows the drive train to begin to free spin, when the vehicle drops back down there would be a sudden spike in load/friction as the weight slams down on the tire and makes it want to stop spinning. Meanwhile the drive train is still spinning/speeding up because it was unloaded moments before.

Doing "little" bounces probably isn't too bad as there's still weigh on the tires so there isn't as much as a violent stop as would be bouncing the tires so bad they unload or even completely leave the ground.

I used to stop even when bouncing a little and change the trucks angle or try a different line but over the years I've loosened up on that rule and will do small bounces here and there.

Another way to think about it.... Imagine putting a Truck on a lift or 4 jack stands and then turning the truck on, putting it in 4WD and locking an axle and allowing the tires to free spin. Then imagine being able to instantly stop one of the tires. The axle is locked, the drive shaft is still trying to spin, and one of the tires just instantly stopped spinning. Whatever the weakest component is will bear the brunt of the "shock" from the tire being stopped.

 

Yes I can. I stopped filming because you where there spinning all 4 for so long my arm go tired of holding the damn phone. Plus I ran out of beer and had to head back to my rig for a resupply. lol

 

Ok, thanks lol
So the only thing I’ll ever have to worry about is spinning on ice and then hitting dry pavement (unintentional) but happens in when leaving stop lights/signs now and then