22 to 23 spline crawlbox adapter/coupling for Manual trans to 4.0L Marlin Crawler Tacobox

Uh... how exactly does this work?

And the advantage is a lower gear ratio? I haven’t heard about these before...

 

Yep, that's basically it. It's a second gear driven reduction case between the trans and the chain driven stock t-case that gives you a low below your low. It lets you go super slow without having to burn up your clutch in those situations where you're trying to find the perfect balance between not stalling the truck and sending it. Or creeping mall parking lots. You do you boo. This shows two gear driven cases versus our chain chases in the 2nd gens, but should demonstrate the idea:

https://youtu.be/m6XJCB2gG9c

In the interest of full disclosure and at the risk of talking you all out of this, Marlin does state in the post below that there's a possibility they'll have crawlboxes, adapter plates, and this magical part...the holy grail of all couplings...available by end of year for MTs, October specifically. If you're waiting on a crawlbox anyway, I have hard time pushing anyone to jump in the deep end with me on this right now. On my end, wheels are in motion already and I'm moving forward with this mod now. There's nothing that leads me to believe that an adapter will be available from Marlin in October of this year or anytime shortly thereafter.

https://www.tacomaworld.com/threads/tacobox-updates.573748/page-10#post-21256009

That being said, for everyone that gave a soft maybe, we can get them at $600 a pop with a hard yes.

1. @Littles
2. @hoverlover
3. @6 gearT444E
4. @JustDSM
5. @Littles
6. @little squirt

So all I wanna know is...

 

BigMike also said they were working on 19 spline couplers in his post. This has me a bit concerned after seeing your (@Littles) 22 spline shaft. I don't want to opt out of this group buy and then get a Taco Box with a coupler that isn't going to work. Who knows how long it would take to get resolved? I'm trying to get back to Moab early next year and I'd prefer to have everything at 100% and tested. That said, if I can save $600 on a coupler and take advantage of the promo, it would save $800+.

I posted on the crawl box updates thread asking about the current Hot August 10% off discount. Depending on what Mike says I'll either keep waiting for my auto crawl box and go with the coupler in this group buy or cancel the order and place another order for a manual crawl box.

Probably not what anyone wants to hear but it's where I'm at right now.

 

BigMike and everyone at marlin is wrong on the number splines. My ability to count is yet another reason I am not putting my eggs in the marlin basket. I feel like they should know the correct number splines that need to be on this adapter that they are putting so much time and thought into engineering...but that's just like....my opinion.



My transmission has 22 splines, so that's what the shop is making me. The shop is going to save the design for me, so when marlin puts out their 19 spline paperweights, and you still need a 22 spline coupler to install your crawl box, rest assured that we can make up another. By that time it will have been Moab tested and proven.

 

Either way I go I could end up with a sweet paper weight.

I think I remember seeing you address the spline count with Marlin. I don't recall a response, did they ever get back to you?

 

BigMike never responded to or acknowledged my post. When I called Marlin a few weeks back to discuss the adapters, I attempted to inform one of his employees over the phone that it is a 22 spline after he incorrectly stated it was 19. He put me on hold to go check and came back a few minutes later to tell me I was wrong. I've given up on them. If they want to continue to perpetuate incorrect information that's on them, but it does not give me much faith in them.

 

OP updated. I have 5 adapters going into production which I am paying for out of my pocket. 3 of them are available at the cost of $600 each (plus any taxes they charge me) on a first come, first serve basis, starting with those who initially expressed interest. Expected to be ready mid-September.

 

Fuck it.
I'm in.

 

That's the spirit!

 

you talk with rock solid toys to see if he needs any for his installs? he does a lot of tacobox work

 

Yep. Wyatt was kind enough to respond to me via e-mail and said thanks but he's going to work with Marlin.

 

i figured he would long-term given his relationship with them, but short-term seems like a good option you got going on here... oh well..

 

September 13!!!

 

Updated OP with the drawings they sent.

 

which is bullshit cuz the 6speed has been out since 05. they for whatever reason seem to refuse to put any support into that transmission. also, the bullshit of spline count. doesnt matter how many people tell them they are wrong, the refuse to acknowledge that. even wyatt's write up he had when he had his forum explained it was 22 spline and not 19. last but not least, their double row bearing is garbage too. there was a big thread over on ttora about it and people having a ball bearing pop out of it. which happened to me. and they still refuse to admit its a bad design.

 

Yeah, I was going to point that out too. Their own Marlin website Forums has people telling them the correct thread counts all over the place.

 

I’m guessing they have all those on ignore

 

Updated OP with price estimates on the oil seal extension housing.

 

Doesn't Big Mike have a 2016 six speed with triple cases? What did he use for an adapter?

Is there a reason that you would not reproduce an Inchworm style adapter that would be more flexible?

Good on you for taking the leap on the machine work. GLWS.