Official Crawlbox BS thread!

If my math is correct




MC adapter are now NOS inchworm. Built your own to save $, TG adapters with MC gear. Nothing wrong with NWF btw. If you want slow, 4.7.

I'm auto with mc 4.7 and have no issue. Been running this set up for many years. Can't go wrong with either set.

 

the 2.8 is the auto 1st gear ratio? If yes then yeah that makes sense. I was hoping for someone with some real world experience might say a setup like that wil work good or if I should definitely use a 4.7 type option in one of the cases (or even the NWF with a 2 speed 3.8 or 4.3 atlas)

I know it comes down to how slow and how strong

 

Only you can define what you really what and need. I personally preferred slow. The slower the better, especially if I'm climbing or going down a gnarly drop. I let the vehicle do its own thing while I steer and grab the OH SHIT handle bar.

My personal opinion, 1t axle should be mate with atlas and toyota axles can still run the rf1a case. That's just me and they all break some how. I seen atlas leak and break, same for Toyota crap. Even seen 1t stranded on the trail, same for 30 spline crap. It really depends on you and what you're intention are but the slower you are, the less likely you'll break stuff.

Happy trail....

 

What is being done about venting the crawlbox? Are you guys venting the trans or leaving the vacuum cap on the trans? The t case has its own vent, which is separate from the crawl box. The trans has a vent that is capped off from factory. So I was thinking either the crawl box vents through the shifter, or the trans vent that’s capped off could be used to vent the crawlbox and moved up since that cavity is now filled with oil. Thoughts?

 

Crawlbox is leaking like crazy out of the shifter housing. Clearly coming from the shifter/ball area. Anyone have a fix for this? Doesn’t seem to be a pressure issue, seems like oil is being directed right at the shifter while driving full time. Truck is covered in oil from about 100 miles. Canceled my rubicon trip because of it.

 

Do you have an oil slinger installed?

 

x2 on this, oil slinger is needed. You can get above or MC has a shifter base that has it built in.



https://www.marlincrawler.com/transfer-case/parts-upgrade/shifter-parts/push-n-turn-shifter-base-kit

 

This is what I’m running, I’d recommend. But cost a lot more.

 

I do not have that. Will order one right now. Trailgear is useless when it comes to questions or issue with literally anything.

 

I’ll Order this one. Looks nice, if it solves the leak I’m 100% for it. You daily your rig or put street miles without issues/leaks?

 

I’ve been running my cases for over year, about 5k miles as haven’t leaked a drop

 

I run the same shifter, just had a 200+ mile drive to an off road park this weekend and back no leaks. Nice shifter base and oil slinger combo, make sure to rtv/seal the shifter base to the tcase and you'll be good to go.

 

I run a paper gasket

https://www.toyotapartsdeal.com/oem...control~shift~lever~retainer~36345-35010.html

 

Hell yea, thanks a lot!! All this work, trip canceled, I was getting really bummed out with the truck covered in oil all on my new stuff.

 

the old Merlin shifters came with a 1/8 threaded hole in the shifter base and you pair that with the deflector and golden. If the craw box isn’t vented it will splooge out the top.

 

Just to clarify, the duals with 4.7 would use the gear driven case with is 2.28:1 so I believe the math is 2.8x2.28x4.7x5.38 = 161:1
(Still a lot lower than 99:1, but just wanted to point that out in case anyone else is looking at this to help make any similar decision)

 

Thats if you are using two gear drive cases. His math was retaining the chain drive case which has a lower stock ratio of 2.57.

 

So you're ditching the chain case and switching to both gear driven passenger drop rf1a case with the 4.7s in the rear and 2.28 front? If that's the case, yes.

 

You are correct. The chain case will have a lower ratio vs the gear.