Official Crawlbox BS thread!

Oh that’s great haha. Literally the email I sent to the almost to a T. My concern is exactly what happened.

 

It really sucks that I’ve already cut a hole for my shifter and sent my driveshaft to be resized and I’m only now realizing this issue. I don’t really want to install it now after reading that pirate tread unless the adapter is better fitting like the stock one I pulled. Do we know what material is used to possibly have one machined out to the correct spec?

 

Yep.

@Anderson5290 there's plenty of short clip and pictures of TG coupler failure. They have a shit ton of play. That's why I said it was normal.

 

Make sure to test fit your tcase. TG have a tendency of shipping the wrong adapter to their buyer. Hence, first gen receiving second gen adapter or visa versa because they like identical except for mounting location.

 

That's Marlin your thinking of.

 

It can't be Marlin. They never have any stock to actually ship.

 

Tested it, mounts right up no issues. The splines on the t case seem to fit the crawlbox nicely, but the other side is the issue.

 

So the only issue with TG is the coupler? What do I do about that? Get a marlin, or custom made? We do know the material used, I assume it heat treated and needs to be pretty tough. I’m already into this case money, time, driveshaft, hole in the floor, beat the hell out of my body. Need this to go in asap for my rubicon trip at the end of the month. Anybody have any suggestions on what to do?

 

Load it up with anti seize and send it. My Trail gear coupler hasn't given me any problems

 

This is the answer

 

Can confirm, happened to me

 

Happened to a lot of people. 2 guys I know had the same issue and got hassled because it took them well over 4 months to start the build after making the purchase. It was TG fuck up and they were giving the buyers a hard time.

 

The original adapter I got sent was correct, but was damaged in shipping. So they sent me a replacement that was for a second gen. So rather than wait another 2 weeks, I just decided to fix the first one that was for the right truck

 

So basically get the marlin coupler and I’ll be good. Any issues with the rear splined portion failing? Seems as though people have had issues with all of the crawl boxes. Trying to do this once and right.

 

I meant adapter. not coupler.
If you have TG gears, I don't think the marlin coupler will work for you.

Sure people have issues, but there are also a lot of people with crawlboxes out there that work fine without problems. This thread tends to highlight the negatives of these setups and what can go wrong. It's useful in that regard though as a reference for things to look out for. Take it with a grain of salt. Not saying any of these thing won't happen to you, but I feel that a lot of that is largely due to how you use your truck and style of wheeling.

 

I called marlin and spoke with Kyle. Cool dude. He gave me specs on their coupler and sent me one. His measures 3.75” vs mine at 3.72”, the od is 1.375 on his vs 1.57”
On mine. And the 23 spline is a slight interference fit so it should be nice and tight. I don’t think the od matters because nothing rides on the coupler. I don’t see why it wouldn’t work. I can easily take it down to 3.72” if that would even be needed. Will update with my findings when it arrives.

 

Ok update on my issue. Marlin coupler came in, I got it yesterday and right away the fitment was a little too tight but the spline interference was not much. I spun the trailgear box and cleaned the OD of splines with a scotchbrite pad. Took the slightest bit of material off, roughy a thou and now the coupler fits perfectly. Absolutely ZERO play in the coupler, fits like it was made for it. The length is slightly longer than the trailgear 3.72”vs Marlin 3.78”. But the coupler fits properly with all of Trailgear’s stuff, I’ve test fit the crawlbox and it doesn’t bottom out or interfere in anyway. The trans side is a press fit and t case is now a very tight slip fit. So for anyone wondering, if you TG crawl box splines/trans splines are still in good shape and not damaged you can get the Marlin to work. Taking off the slightest material did not change how the TG coupler fit because of how the splines engage. The TG splines come to more of a point vs the Marlin more squared off like the factory coupler.

 

Think it would be okay to heat one a little to get it to fit?

 

I guess you could on the part that goes on the trans, but the t case side needs to slip on and off otherwise it will be very difficult to remove once’s it sealed. I grease mine up, lined up the splines and hammered it on like they told me.I measured it beforehand and was confident it would fit. Just used a thick chuck of aluminum to save the end of the coupler.

 

I’m building a 2004 v6 automatic Tacoma. Going to run one tons with 5.38 and 42” tires. Anyone here think the NWF 2.57X2.57 (both chain drive cases) isn’t low enough for Rubicon type slow wheeling? I’m considering canceling my order and going with a 4.7x2.57 gearing of a TG or MC. Seems most people that run the NWF don’t run that big of tire so I’m having a hard time getting an apples to apples comparison. Sorry, I know everyone hates these type of questions.