4 lo position question

I have an 05 and in the 4 lo locked position is there supposed to be a constant beep going off? The caveat is the truck is up on jack stands on all fours so I can try to determine which front wheel brg is giving me problems. I thought by putting it in 4 lo position I could get both front wheels to rotate but not so, only one side rotates. I think its because only the least resistive side is spinning.
But anyways, I never noticed a beep before but it has also been along time since I had it in 4 lo.

paul

 

Constant beeping likely means it's not actually in 4Lo, is the indicator light on the dash blinking or solid?

 

At a full stop shift into neutral. Then move the selector to 4 Lo. If it beeps, it's not in Lo.

 

This!

 

Ok so with the gear selector in park I put it in 4 lo then put the gear selector in L 2 and let off the brake (keep in mind I have all wheels up on jacks to rotate the 4 wheels).

 

I would try moving the transfer case into 4lo while in neutral as opposed to park. I’m not quite sure how the automatics are programmed (mine is manual).

 

Wheel bearings also seem to be a “weak” point on an otherwise bulletproof truck. The front-end bearings are not hard to replace. Just make sure everything is torqued, and don’t be afraid to do both.

However, there’s also something to be said for “if it ain’t broke, don’t fix it.”

 

Do or Do Not! There is no Try!

Put it in neutral! Put it in neutral!

 

I will put it in neutral. So will both front wheels spin then or only one with the least amount of resistance? Thanks

 

Google differential, I'm not too certain that you can find a really good explanation on the net. My auto shop teacher had one rigged to sit on a bench ( circa 1965) and a hand cranked flywheel to drive it. Power gets fed to the output side that spins most freely. Apply a brake to that free spinning side - and that amount of torque will then be applied to the other side.

So put someone in the driver seat a and have them apply the brakes - slowly while your hands are safe. The braking may dampen the bearing noise tho ........

 

Both will get equal torque and should spin unless one has lots of bearing/brake drag.

If one isn't spinning you could manually add drag to the spinning wheel to get the other going.

If 4LO light is blinking and beeping everything isn't engaged.

 

I may be wrong but when you’re in 4L your front axel is open meaning you get power to only one wheel at a time. So I’d expect only one wheel to turn at a time. When it’s beeping the system is sensing that the 4L is not engaged. I think this is a false reading caused by both front wheels being off the ground. If 4Lo isn’t engaged then neither front wheel should turn. Put it back on the ground, put it in 4L and I bet the the beeping stops.

 

Yes, you're wrong. An open differential outputs equal torque to each wheel limited to the torque available at the least tractive wheel. "Power" is not just sent to one wheel with an open diff. People just can't grasp this. In this case the least tractive wheel is the one with the least amount of friction, but the friction in each should be close enough that the drag in the lower friction wheel is still enough to overcome the friction in the other once static friction is overcome. A little hand drag in the moving one will probably get everything going.

The truck has NO idea the tires are in the air and this will not affect 4LO operation.

 

The truck has NO idea the tires are in the air and this will not affect 4LO operation.[/QUOTE]
Maybe, maybe not. Just put the truck on the ground in 4L and let us know if it’s still beeping. (Was it beeping in 4L prior to putting the truck off the ground on jack stands?) Again if 4Lo isn’t engaged then neither front wheel should be turning.

 

The front wheels get power in 4Hi as well

 

Of course they do but the discussion concerns only 4L. There is no mention of putting it in 4H, that’s why I only talked about 4L.

 

To engage 4Lo on a stock Tacoma, it first has to be in 4Hi, therefore the front wheels would already be spinning. If in park you spin the dial to 4Lo and then go to D, the transfer case and ADD will activate and put the truck in 4Hi but will not engage the low gear and cause the truck to yell at you.

 

All I’m saying is put the damn truck on the ground and see if it still beeps in 4Lo. If it doesn’t beep than it has something to do with the wheels being off the ground.

 

It has everything to do with not being in neutral to engage 4Lo, I've put my truck in 4 Lo on jackstands, totally doable if you follow the instructions on the sun visor.

 

Maybe, maybe not. Just put the truck on the ground in 4L and let us know if it’s still beeping. (Was it beeping in 4L prior to putting the truck off the ground on jack stands?) Again if 4Lo isn’t engaged then neither front wheel should be turning.[/QUOTE]

It's because he tried putting it in 4L from park. Has nothing to do with the wheels being off the ground. The beeping is an error because the proper sequence to get it into 4L was not followed. The truck can shift into 4H from park but not 4L, which is why he is seeing a front wheel spin.