Why does the 4x4 light blink sometimes?

[downshift]

I understand why it blinks when there is a switch to engage 4X4. There is some actuator that needs to be sure conditions are right before it changes the gears. But my 2017 TE has a lever operated transfer. The lever physically moves the gears from 2x to 4x. There is no waiting. And as far as I know, the hubs are always locked. So why does the light blink?

 

[3wbdriver]

There is a sleeve and electric motor actuator in the front axle (passenger side I believe). When you engage the lever into 4wd the actuator up front slides the sleeve over splines on the axle shaft. The light blinks until the sleeve seats over the axle. Sometimes you may need to rock the steering side to side a little while rolling forward to get the splines to align with the sleeve. They use this system instead of locking hubs now to reduce wear on the front diff.

 

[downshift]

There is a sleeve and electric motor actuator in the front axle (passenger side I believe). When you engage the lever into 4wd the actuator up front slides the sleeve over splines on the axle shaft. The light blinks until the sleeve seats over the axle. Sometimes you may need to rock the steering side to side a little while rolling forward to get the splines to align with the sleeve. They use this system instead of locking hubs now to reduce wear on the front diff.

Interesting... So the front drive shaft is not turning when I move the lever into 4wd? Why don't the gears grind if I shift into 4wd when driving?

 

[SSDuck8]

is your a trac button pressed?

 

[Judd94]

It also works much better if you yank the transfer case shifter rather than be gentle

 

[nb rob]

as 3wbdriver mentioned, it's called an automatic disconnecting differential, or ADD.

We still require this sleeve to engage to get 4x4, even with the manual T case.

 

[wfo9]

Interesting... So the front drive shaft is not turning when I move the lever into 4wd? Why don't the gears grind if I shift into 4wd when driving?

The manual t-case shifter will engage the front drive shaft mechanically, but your passenger side CV axle will still be disconnected until the ADD actuator slides over and hard connects that axle to the diff. Until then you are still really in 2wd with no power going to the front wheels.

Interesting odd design choice of these trucks is you cannot engage 4wd if any type of CEL is on. So if your gas cap is loose, or your cat efficiency reports an error.. no 4wd for you. This is why it is critical to carry a code reader along that can at least clear basic codes. Otherwise you can be SOL for very stupid unrelated stuff. No pure mechanical engagement or disengagement mechanism available like the good old days. Same if you bust a CV.. You basically have to fix it (or insert a stub) to get back on the road.

 

[AZ_Trails]

Related question on my 2018 TRD ORP. Compared to my 2000, this thing is extremely hesitant to go in and out of 4H.

If I shift the lever to 4H, the dash light will blink - if I then shift the lever back to 2H the light still continues to blink. Does anyone else also have this behavior?

Seems like the light should turn off immediately when back in 2H since the ADD never clicked in, but that’s not what I’m seeing...

 

[downshift]

The manual t-case shifter will engage the front drive shaft mechanically, but your passenger side CV axle will still be disconnected until the ADD actuator slides over and hard connects that axle to the diff. Until then you are still really in 2wd with no power going to the front wheels.

Interesting odd design choice of these trucks is you cannot engage 4wd if any type of CEL is on. So if your gas cap is loose, or your cat efficiency reports an error.. no 4wd for you. This is why it is critical to carry a code reader along that can at least clear basic codes. Otherwise you can be SOL for very stupid unrelated stuff. No pure mechanical engagement or disengagement mechanism available like the good old days. Same if you bust a CV.. You basically have to fix it (or insert a stub) to get back on the road.

It still seems the gears would grind when I shift into 4wd when driving. The front drive shaft isn't moving but the gears in the transfer are moving.

Plus, the driver side axle would is spinning all the time, spinning that side of the diff along with it. 3wbdriver said this is to reduce wear on the diff, but this seems like it would cause uneven wear. Spinning both sides of the diff from the drive shaft seems better to me.

 

[wfo9]

It still seems the gears would grind when I shift into 4wd when driving. The front drive shaft isn't moving but the gears in the transfer are moving.

Plus, the driver side axle would is spinning all the time, spinning that side of the diff along with it. 3wbdriver said this is to reduce wear on the diff, but this seems like it would cause uneven wear. Spinning both sides of the diff from the drive shaft seems better to me.

That is not how an open diff works. The spider gears are spinning all the time not the ring and pinion.

There is nothing to grind. When you shift to 4wd the fork slides over and the chain starts to drive the front output which has no load on it yet. It's designed for this as long as you are under 50mph and at a steady speed...

Once the drive shaft is spinning.. the ring and pinion gets up to speed and the two side gears are at even speeds as long as you are not turning sharp. The splines still need to line up, thus the blinking and occasional need to turn a bit to one side to get things lined up.

Shifting to 4Lo is a different story.. There you have to stop and go to N as there are gears to mesh and no syncros.

 

[downshift]

That is not how an open diff works. The spider gears are spinning all the time not the ring and pinion.

There is nothing to grind. When you shift to 4wd the fork slides over and the chain starts to drive the front output which has no load on it yet. It's designed for this as long as you are under 50mph and at a steady speed...

Once the drive shaft is spinning.. the ring and pinion gets up to speed and the two side gears are at even speeds as long as you are not turning sharp. The splines still need to line up, thus the blinking and occasional need to turn a bit to one side to get things lined up.

Shifting to 4Lo is a different story.. There you have to stop and go to N as there are gears to mesh and no syncros.

That makes sense, thanks. No load on the front drive shaft so the chain can just start driving it.

Yes, I know the spider gears are spinning all the time, that's my point. Normally, spider gears only spin a small amount to allow for the left/right difference, like going around a corner. But with the sleeve disconnected, the spider gears will be spinning much more than that. Say you're driving at 80MPH. With the sleeve disconnected, it would appear to the diff that the left wheel is going 80MPH while the right wheel is stopped. This would all be taken up via the spider gears. That seems strange to me.

 

[rihavens]

It also works much better if you yank the transfer case shifter rather than be gentle

Is this true?

 

[3wbdriver]

Not necessarily. Just shift it with authority.

 

[hb216]

Is this true?

Yes. And enjoy it. Cooler than twisting a knob or pushing a button. Old school.

 

[e60ral]

it also gets much easier to go into 4hi and 4lo after you've used it a few times

 

[empty403]

I understand why it blinks when there is a switch to engage 4X4. There is some actuator that needs to be sure conditions are right before it changes the gears. But my 2017 TE has a lever operated transfer. The lever physically moves the gears from 2x to 4x. There is no waiting. And as far as I know, the hubs are always locked. So why does the light blink?

FYI, you have an Off-Road model. They stopped making the “Trail” model back in 2014 or 2015.

 

[e60ral]

FYI, you have an Off-Road model. They stopped making the “Trail” model back in 2014 or 2015.

'16, '17 is the first year for off-road

 

[AZ_Trails]

Related question on my 2018 TRD ORP. Compared to my 2000, this thing is extremely hesitant to go in and out of 4H.

If I shift the lever to 4H, the dash light will blink - if I then shift the lever back to 2H the light still continues to blink. Does anyone else also have this behavior?

Seems like the light should turn off immediately when back in 2H since the ADD never clicked in, but that’s not what I’m seeing...

Can anyone tell me if they experience the same thing with the continued blinking?

 

[csw2001]

Can anyone tell me if they experience the same thing with the continued blinking?

Happens occasionally but does go away if I shift back. I'm not worried about it.