UPDATED - Now with Twin cases and triple sticks "El Taco Diablo" 4x4 swap and B.S.

Lower bolts circled in red bolt your transmission extension housing to that TG adapter. Bolts start on the trans side and thread into the TG adapter plates holes. Middle orange circle larger hole is an oiling hole. Right behind that is the lower bearing for the cralwbox. TG adapter to transmission extension housing must now be sealed with rtv because that cavity now fills up with fluid for more oiling capacity.
Upper orange circled area is for the shifter shift rails to move back and forth. Just add some anyiseize or the like to prevent dry shifting when first putting together.

 

There's no way to use those bolts to bolt to the trans extension housing.
A) There's no holes in the trans extension housing to put those bolts through.



B) If there were holes in the trans extension and I bolted the tcase to the trans extension from the side inside the trans... there would be no way to bolt the extension housing back on to the transmission.

I think the bolts that go there are just, basically, plugs... BUT I'm seeing (I think) on @theesotericone write up on T4R that he had studs threaded in those holes.

 

You sure you have the right adapter? Those holes were used with my manual trans

They sent me the wrong adapter when I did an exchange since the original one got damaged in shipping.

 

You havn't finished all the "unmentioned mods" to fit the crawlbox. You need to drill out a hole, marked in red. Both green arrows are where the bolts start (these are flange on the transmission extension housing) that line up with your adapter. Both bolts fit through these holes (where the green arrows are, bolt go through the extension housing and thread into your adapter.) Both are accessible when the transmission extension housing is bolted into place.

 

I'm thinking the adapter is the same whether it's for Manual or Auto and you just plug those holes with the bolts.

The instructions (the new instructions sent from Trail Gear) appear to show the same plate for Manual or Auto
https://trail-gear.com/media/downloads/pdf/instructions/107517-1-INS.pdf

 

Ah ok. Your prob right on that

 

OK... Now THAT makes sense.

What a fucking cluster fuck... why wouldn't they mention that IMPORTANT little tid bit in their instructions? Even the "NEW" instructions they just sent me. Or, the email they just sent the link in.


For real bro... I owe you a beer. You, Matt, Ian and others... I really appreciate your help here.

 

Ended up I was totally wrong. I was looking at it wrong. @ToyRyd04 put it in terms a dumbass can understand... now I get it

 

No worries, I enjoy building these and there are some gaps in knowledge even in the instructions. **Because these thread into your adapter and will be emerge in oil, you'll need to coat the bolts in RTV/FIPG to have it seal properly or you will have leaks.**

You will also need to scuff that powder coat orange mating on the adapter surface for RTV/FIPG to seal properly.

 

100% Gray RTV has been my friend thus far.

I'm still leary about the hole I can see the bearing through... but that must have been sealed somehow when they built it (from the inside).

So, I'm thinking the front case to Trans extension housing is still a "dry fit" meaning there is no need to RTV that connection. (The connection between the front case and back case WILL need to be sealed with RTV)

 

Hopefully, since we are working out these things in tiny simple dummy steps, this thread can be a source of info for others in the future.

 

Oh the joys of installing these LOL!!! Imagine how shitty the instructions were in 2007 when I first built mine, none, LOL!! A few more unwritten tips: coat the splines of your tcase in anti seize, this will prevent fretting corrosion which will strip out your input shaft. Also drain the fluid evrey 6months, and if it's red, drop the cases because your input is rusting and fretting out. If that was covered earlier ignore me.

I also only use permatex "the right stuff" to seal everything, I had horrible luck with ultra grey. DO NOT goop that shit on thick, it can fan out and cover up oiling holes in the adapters.

If it doesn't say in the instructions, you are going to have to cover the trans mount holes with JB weld so your fluid doesn't leak out those holes in the trans cavity.

I have built a bunch of these and a lefty, feel free to ask away.

 

Interesting to see how that works. I would be worried it somehow comes off the coupler and clogs up some passages in the crawl box. I used some STUPID expensive hi temp moly grease on one of mine and it flung off into the case. Anti seize has been going strong since 2008.

 

Are you referring to the trans mount holes for the mounting bolts from the trans mount on the trans extension? The bolt holes don't come through in to the cavity between the front case and the trans... inside the trans extension.

Or, are you talking about the bolt holes in the front tcase for the mount?

 

I'm talking where the factory trans mount mounts to the trans. Run your fingers over those holes, they open up into the cavity.

Shit never mind the auto is different than the manual, carry on!!

 

The hole you can see the bearing is an oil flowing hole for the lower bearing pressed onto the gears. Without that hole, the crawlbox would only have about 3/4 of a quart of fluid capacity. Too low for something that sees a ton of heat and friction. That hole allows gear oil to fill the transmission extension housing to add capacity which brings it to 1.5qts give or take. So thats why the transmission extension housing and adapter plate must be sealed properly otherwise you will certainly have leaks. On manuals, that same area needs to be sealed where the 4 bolts thread into the extension housing because they are factory tapped into that cavity. *Most* autos the factory did not thread all the way in.

 

5 years since install with lots of hard wheeling and a decent amount of highway miles. My crawl box has never leaked other than when I forgot to include the oil slinger when I first installed it. Will it be a bitch to get out? Yep. Do I think it was worth it? So far yes

 

100% answered that question. I will double check it though, before I slap it together. And JB weld those holes if they are there.

 

I'll be another test subject on the RTV coupler.

Cause I RTV'd the shit out that sum'bich last night.

 

Sweet. Maybe we'll be the new go-to. Like said above, anti-seize has been used for a long time