July 7, 2023

2023 4runner - 4WD - the transfer case

There is a separate page about all the fancy stuff (Atrac, locker, etc).

Note: the manual recommends driving in 4WD (either hi or lo, it doesn't say) for at least 10 miles each month!!

My 4runner has a "shift knob" for the transfer case. The owners manual calls this "type A".

To shift from 2H to 4H, you simply need to be going at less than 50 mph. The manual puts no restrictions on shifting back to 2H. I think it is a fair bet you won't be driving over 50 mph in 4H, other than the case where you forget and take off down the highway in 4H. What then?

To shift from 4H to 4L or back from 4L to 4H, the vehicle needs to be stopped, brake pedal pressed, and main transmission shift lever in N. Note that the manual calls the main shift level the "shift lever". It calls the transfer case lever the "front wheel drive control lever".

The ratio

The Gen5 4runner gives a 2.566 reduction in low range.

And for fun, here are the ratios for the other gears: 

1st - 3.520
2nd - 2.042
3rd - 1.400
4th - 1.000
5th - 0.716
Rev - 3.224

Here are the ratios for my Gen1 Tacoma. They say the W56 manual was used with 4 cylinder engines and the R150F manual was used with V6 engines. 

Transfer case - 2.57 (same as the 4runner)
1st - 3.830
2nd - 2.062
3rd - 1.436
4th - 1.000
5th - 0.838
Rev - 4.220

Here is a whole chart for a wide variety of Toyota transmissions.

And of course you should also be wondering about the ratio in the rear differential.
The door jam sticker in my Tacoma says "B03A/R150F". The second part (R150F) confirms that for the transmission. The first part is for the differential, as follows: 
B = 8 inch ring gear
03 = 4.10 ratio
A = 2 Pinion open (not limited slip)
What about the 4Runner? It has a 3.73 differential.

The locker

This locks the rear differential.

Stop the vehicle, put the shift lever in N, and try 4L first Then press the locker button and gently give it gas until the locker indicator comes on. They say not to use it any longer than necessary. Be sure the wheels aren't spinning when you try to engage it.

What about locking the center differential?

This only pertains to a full time 4wd 4runner and any talk about this can be ignored for a model like mine with a transfer case. The only 4runner model with such a thing is the "limited", and as my friend Andrew says, it is indeed "limited" giving you comfort and looks in lieu of 4x4 performance. Just the thing for the soccer mom.

If you had a limited you would get: 

H2 - plain old 2wd
H4F - high 4wd with diff unlocked (more or less AWD)
H4L - high 4wd with diff locked
L4L - low 4wd with diff locked

Here is a video that talks about all this and is very much worth watching. If you have a 4runner like mine with a traditional or "real" transfer case, at least watch the first 20 minutes.

The bottom line is that there are two very different kinds of transfer cases.
Have any comments? Questions? Drop me a line!

Tom's Auto repair pages / tom@mmto.org