05-15 2wd to 4wd conversion guide (for dummies)

yea it just slightly hurts MPG since there's increased resistance.

 

my truck already barely gets 12 mpg so it aint going to help

 

mine gets 10.5 lol, with switch off

 

I picked up an ADD switch from @12thstateoffroad
Super easy to install, and i like the option to dis engage the front all together.

 

I’ve basically got the same thing except bought it from rock solid toys aka scam artist central before they went under

 

I had a similar leak on mine. If the axle seal is too deep or shallow it will leak but what I ended up doing was loosen the diff mounting bracket bolts and shifted the entire assembly. It looked like the diff was not completely centered on the passenger side. After I did that it stopped leaking.

 

@jawmes, Here are a few. I can put a tape measure on the lengths as well if you need. We used 1/2' cold roll bar. Chopped the shifter just before it curves and built from there. I can tell you the damn clip holding the shifter in place was a bitch. Thread pitch is M12 -1.25 if you buy a bolt to weld to the shaft, or reuse to original shaft.

 

Nice

 

Hey guys, I finally got everything going (not as cool as everyone here, had a shop do the transmission swap, got a Jasper w a 3 year 100k warranty) but I've found myself overthinking how to shift into 4x4... I also got the 12thstateoffroad switch & want to confirm-

Should I engage ADD and leave on before shifting into 4x4 and leave on while in 4x4? The shop that did the work told me to shift into 4h first then engage ADD... literally just got the truck back today and don't want to do any major damage.

I came across this other thread which confused me a bit https://www.tacomaworld.com/threads/add-front-diff.197572/page-2 but wanted some info from the pros if you could help me out again @pdaddy @Ricardo13x @Yacob_D @MA_TACO

 

The way the factory system works is to engage the transfer case first then once in 4x4 it will engage the ADD motor. The way I like to control the system after modifications is different. I "lock" the ADD like a free wheeling hub the morning before I'm going wheeling (fully stopped), and then shift in and out of 4wd via the transfer case as needed. To each their own. The best method is the 4wd confidence brought to you by the FJ tube.

 

by the way i hope your jasper holds up, those guys can't build a subway sandwich if their life depended on it.

 

I've done it both ways. I'll come to a complete stop, put it in neutral, shift into 4wd then engage the ADD switch or the other way around. I'll wait for the little light on the switch to come on to tell me it's engaged then start moving. Sometimes the little light won't come on depending on the type of ground i'm on so I'll creep forward and pop it in neutral again to help the ADD sleeve splines line up while hitting the switch and it usually works. I believe you can switch to 4wd up to 50 mph but I don't trust that.

 

Damnit... initial driving it seems pretty smooth, I almost like how it shifts better than the original hopefully it holds or if I have any issues it's in the first 3 years

 

i switch 4h under 50 and neutral then 4l

 

As others have said, if you are stopped it doesn’t matter what order you shift the transfer case and ADD. If you are moving then you need to shift the T-case first then the ADD. Getting out of 4WD is the opposite; ADD first then t-case. If you do it in the wrong order you get a loud bang and a big jolt.

 

Quick confirm- do you leave ADD switch on the whole time you are wheeling until you switch back to 2WD, then flip the switch off?

 

Yes switch it off once you're done wheeling and on paved road.

 

What I found using the switch from 12thstate is like @6 gearT444E said. When I pull up to the trail I hit my ADD switch and leave it engaged the whole time im out. The other guys that did the swap may have chosen to delete the ADD all together. @Ricardo13x has his nonADD. With it always on you can switch in and out of 4x4 as needed on the trial! MIne has been working very well. Also it seems to engage better while in park.
Congrats on the Swap start!

 

Awesome, appreciate the responses everyone. I like the leaving ADD on approach best, but I did some experimenting this morning and both seem to work. One interesting issue I am coming across is that after 1 minute driving in 4H the transfer case drops me back into 2WD- no loud pop or grinding, just seems like I can’t sustain 4H for much longer than a minute.

 

that def is not normal. I would confirm under the truck that the front driveshaft has disconnected.