Crawler Box Splines keep stripping.

Nice rigs and to answer your questions, yes the female coupler was replaced everytime since it also stripped its inner splines. And no anti-seize was used. I used marine grease when mating coupler and input shaft, which was recommended by my fabricator.

 

Never used 4x4 on pavement unless there is snow and ice on the ground.

 

Think you can send me their link, curious to dig in that thread.

 

Lot's of good stuff here.

https://www.tacomaworld.com/threads/official-crawlbox-bs-thread.422186/

 

I was speaking in context to this board in terms of hardcore. Sure, once you go buggy... links, tons, 42's, ls, and an Atlas, make a ton of sense and I wouldn't build anything else if I was committing to a buggy. It doesn't mean that mini truck duals/axles/leafs don't have a place for budget minded mini-truck guys that don't want a $30k single purpose buggy.

You came across as condescending when you post in a thread where OP is just trying to get help on an unusual transfer case issue, offer no advice except to say that he should have gotten an Atlas or a Hero.

 

This really looks like an issue of water ingress into that splined area.

Also REALLY surprised the need for a crawlbox on 33's.

 

Cool story.

 

Sounds like that may be the issue right there. If that front diff came from a Manual truck it will have 4.10's

 

So that aside.. can someone explain why everyone keeps pointing to different gear ratios as a potential cause? My understanding is OP's carnage is before the transfer case. Right? Im genuinely curious why different ratios in the diffs would have any impact on any part of the drivetrain before the transfer case.

Seems to me X torque would go into the box, Y torque comes out then goes into the transfer case and from there on you would have problems if the ratios are off..?

And OP said 2/3 times he was in 2WD. So again Im not seeing why the ratios would cause this failure.

 

TL;DR

Still curious what’s up with OP though

 

It didn't come across as condescending to me. At just came across as a statement. A true one, IMO.

First, I've got TG adapters that haven't failed and I've wheeled my IFS pretty hard for what it is.

Second, everyone's idea of what hardcore is varied. To some guys things like the Dusy or Rubi are "hardcore". For them they probably are. If you want to run the real Hammers trails, Sand Hollow, or the other truly hardcore trails tons and Hero's are the way to go if you can afford it. For me it's been a progression. I've done all my "bucket list" stuff in my rig. Then I realized I am limited. 35's and dual cases will only get me so far no matter how good my driving skills are. I ran Fordyce last month and that's what made me commit to building a purpose built buggy. The whole time I felt like on was on the edge of what my rig was capable of. So, that means it's time for a new rig so I can push my personal idea of hardcore even further.

TLDR: Hardcore is what you make it.

 

I agree with this. The different ratios would increase the required torque but I would expect the torque is still less than the design capacity of the crawl box. The crawl box should be able to handle the max torque of the motor x the reduction ratio x a safety factor.

 

This!! Agreed the frnt diff in 2wd has no effect on the transfer case. Running 2 different ratios in 4wd is asking for trouble.

 

While I don't understand all the mechanics, I think the general consensus is that MAYBE different gear ratios between the front and rear diff have created stress in the drive train that caused the fretting of splines between the tcase and and crawl box....but ONLY when in 4wd. The catastrophic failure that has occured in 2wd doesnt mean it wasnt created in 4wd and finally gave up on the highway in 2wd.

 

Hmm. So many people chimed in saying to check it out I figured they all knew something I didnt haha

 

Others have mentioned poor lubrication . I see in the pictures that the splines are dry all the time . What would it take to drill and tap a fill hole and a drain plug ? This could simply be a lack of proper lubrication . Not something I am familiar with cuz after market . Considering the OP has eaten 3 of these already , I wouldnt be throwing new parts at this again until I knew what the issue was . Is there a chance a lubrication hole was " Not " drilled through the aftermarket case ? As far as I am concerned , there should be gear oil between these two pieces . How about drilling 2 holes in the female adapter to get some fresh lube in there ? Shouldnt there already be a couple holes drilled in that female adapter ? Your factory transfer case has a fluid pump ...is it working ? Did the aftermarket take into consideration the extra lubrication demand by the factory transfer case pump ? I have seen thousands of issues with improper lubrication in domestic factory vehicles . It wouldnt suprise me if the aftermarket is any different

 

I'm with others betting the front ratio is different than the rear.

Yes the tcase will take a beating from the mismatch, but the load will require significantly more torque 100% of the time in 4wd and the weakest link here must be this adapter in the setup.

Just my $.02