Dual t-case crawl box in Expo rig?

[Sundodger]

My 1988 4runner is my daily driver/fishing/hunting/camping/mini expo rig.

I do a lot of freeway driving for my various adventures, but also a fair amount of mild wheeling once I get there. The one thing my truck is missing is a granny gear, growing up with 70's pickup trucks I absolutely love being able to launch on the idle governor on a 30 percent grade and idle up it.

Since no granny gear trans is available for a yota stacked t-cases seems to be what the Toyota guys use for wheeling to get the gear reduction they need but still keep the axle ratios in check, but wondering how they do in our sort of application.


Effects on long freeway drives?
Thermal loading on the t-case for towing?
Fuel economy impacts?
Other?

Looking for some real world feedback. Thanks!

 

[Toyofast]

Effects on long freeway drives?

None.

Thermal loading on the t-case for towing?

None, but I've never towed with my dual case Toyota.

Fuel economy impacts?

None noticed.

Other?

Once you have it you'll wonder why you didn't do it sooner!

Looking for some real world feedback. Thanks!

Besides the cost for dual case adapter, second case, drivelines and new cross member or modifying stock crossmember.... It's going to be an investment but it comes in handy so many times.


My Toyota sees road use along with typical Toyota wheeling/exploring. Running stock 2.28 case and AA 5.0 gears in rear.

 

[Rexsname]

I really enjoy having my Marlin Crawler. 2.28 and 4.7 ratios in the T cases. I did notice a slight hit in Freeway MPG's. I wonder if it would be possible to just have the very low ratio in the single factory T-case. I don't spend much time at all in 2.28 and spend a majority in 1-1 (high range) and 4.7-1 (very low range) double extra stupid low can be fun but isn't used all that often in my case.

REX

 

[v_man]

I'm running dual cases , 2.28 in front of a 4.7 , with a twin stick on the rear case that allows you to use all your low gears in 2wd or 4wd . And I have the crawling gears with both cases engaged , so that makes for 20 forward gears and 4 reverse . I will say that they are wonderful , and that doesn't even really pertain to rock crawling . You always have the right gear for any terrain or situation , snow , sand , steep stuff , I get into my 2.28 case when I am up at higher elevations because the 22re is so underpowered .

The drawbacks are the setup costs , although it is not mechanically a very difficult job , but once you have it you will be thankful .

I have nothing bad to say about them , just keep the oil topped off in the separate cases , and don't mind the whine from the 4.7 case , as that sounds bad but it is normal ...

 

[Sundodger]

Thanks guys.

I was thinking of running the stock gear sets in both. Once I get to my place of adventure I like having the front hubs locked, but to be in 2wd. I find myself needing a lower gear just to drive around, but don't need/want 4wd. So having one in low, hubs locked, 2wd sounds pretty good. If I need 4wd I can throw the second t-case into 4wd high or 4wd low.

I would still rather have a trans with a granny gear for convenience, but I think this should get me the functionality.

 

[Sundodger]

just keep the oil topped off in the separate cases , and don't mind the whine from the 4.7 case , as that sounds bad but it is normal ...

Have you had leaking issues?

 

[v_man]

Yes leaking from the shifter boot on the 4.7 case , it's pretty common issue if you look online , but it's heavy gear oil so it's really not that bad . Maybe a top off in oil 3-4 times a year .

edit : the 4.7 case uses a separate oil supply from the transmission and 2.2 case , and the 4.7 only holds about a quart so you can potentially get low pretty fast ...

 

[Toyofast]

The benefit that I love the most by having dual cases is having various 2wd low options. Comes in handy backing a trailer up into a tight spot and annoying people while in stop/go traffic.



If I were to install dual cases into a DD type rig, especially one that doesn't see big rocks, I'd only do stock gears in rear case(2.28). But I'd highly recommend twin sticks.

 

[01tundra]

Dual cases were good, but I really liked my 4-speed Atlas!