Lost all of my gears?

[JTS197]

Did you jack the front tires off the ground to test this?

I have not. Should both sides be off the ground at the same time? Would I be looking for one of the wheels to spin?

Given that I see the front driveshaft spinning when I accelerate, without any power going to any of the wheels, the problem definitely seems to be up front, and not the TC correct?

 

[Inv4drZm]

I have not. Should both sides be off the ground at the same time? Would I be looking for one of the wheels to spin?

Given that I see the front driveshaft spinning when I accelerate, without any power going to any of the wheels, the problem definitely seems to be up front, and not the TC correct?

Oh, nevermind, I get what you were trying to do now.

I'm not sure if this helps but this is my experience.

I grenaded the rear ring and pinion on a trail in moab and limped it off the trail. Whenever a R&P breaks it drives fine for about an entire tire rotation until it catches, or looses mesh on the broken part of the teeth, and you can feel a huge shudder/metal grinding noise until the teeth mesh up again. This keeps your speed to a max of 3 mph with a large 'hiccup' every couple feet. I did manage to hear gear grinding noises (like what you said) shifting maybe to park, or out of park, I don't remember, when loading onto the trailer.

But I don't know of any other failure mode of differentials other than a destroyed R&P which you would have definitely noticed.

 

[ac1617]

I am not sure if this would make sense, but I went outside to see if I could tell if either one of the CVs was bad. I used my phone to record each side to see if the CVs would rotate when I applied power. If they rotated while I was applying power that should indicate that CV was bad correct?

Well, neither one moved. However, I did not notice that the front driveshaft was spinning when I accelerated. Could it be a bad front diff? If none of the wheels are getting power but I can clearly see the front diff spinning under acceleration, that would make me think the front diff is the problem?

There is your answer. Your V8 has full time 4WD so there is a variable split of power to the front and rear drive shafts when the Torsen center differential is unlocked. Since the differential is unlocked, power will always go to the path of least resistance and in this case, sounds like something is broken in the front differential allowing the drive shaft to spin freely without resistance. Given that the Torsen center differential is essentially a limited slip, I wonder if you get any vibration or rumbling when your front drive shaft is spinning freely as the diff should be trying to "lock up" and send power to the rear.
Regardless, you say when you lock the differential you can get the truck moving, that's because you have a physical lock that forces a 50/50 power split and your rear driveshaft is being forced to spin alongside the front driveshaft (ie. Power is no longer going to the path of least resistance).

Hope I did a decent job of explaining what's happening. This definitely sounds like a front differential issue.

 

[JTS197]

Oh, nevermind, I get what you were trying to do now.

I'm not sure if this helps but this is my experience.

I grenaded the rear ring and pinion on a trail in moab and limped it off the trail. Whenever a R&P breaks it drives fine for about an entire tire rotation until it catches, or looses mesh on the broken part of the teeth, and you can feel a huge shudder/metal grinding noise until the teeth mesh up again. This keeps your speed to a max of 3 mph with a large 'hiccup' every couple feet. I did manage to hear gear grinding noises (like what you said) shifting maybe to park, or out of park, I don't remember, when loading onto the trailer.

But I don't know of any other failure mode of differentials other than a destroyed R&P which you would have definitely noticed.

That does help and it makes me really think it is the front diff that is bad. Given that when my 4Runner rolled off the trailer, and started to drive normally, the front diff may have spun enough to catch on the part of the ring that had teeth, to drive around. And then once it spun around and got to the bad part, the transfer case just sent all the power to the front (least resistance) and the front diff could not engage because the ring is jacked up.

That would explain why I see the front driveshaft spinning with no power to any wheels. And then why locking the center, I was able to move, because half of the power was sent to the rear.

Thanks for the help everyone. Hopefully the front diff is the issue. I am taking it back today.

 

[JTS197]

There is your answer. Your V8 has full time 4WD so there is a variable split of power to the front and rear drive shafts when the Torsen center differential is unlocked. Since the differential is unlocked, power will always go to the path of least resistance and in this case, sounds like something is broken in the front differential allowing the drive shaft to spin freely without resistance. Given that the Torsen center differential is essentially a limited slip, I wonder if you get any vibration or rumbling when your front drive shaft is spinning freely as the diff should be trying to "lock up" and send power to the rear.
Regardless, you say when you lock the differential you can get the truck moving, that's because you have a physical lock that forces a 50/50 power split and your rear driveshaft is being forced to spin alongside the front driveshaft (ie. Power is no longer going to the path of least resistance).

Hope I did a decent job of explaining what's happening. This definitely sounds like a front differential issue.

You did! I did not see this before I posted my last one.

I definitely am getting some rumbling when I put it into drive. I hope a new diff fixes it.

Off topic question - assuming that I get a replacement front diff, I should be able to rebuild the bad one myself and have a spare?

Thanks!

 

[Inv4drZm]

That does help and it makes me really think it is the front diff that is bad. Given that when my 4Runner rolled off the trailer, and started to drive normally, the front diff may have spun enough to catch on the part of the ring that had teeth, to drive around. And then once it spun around and got to the bad part, the transfer case just sent all the power to the front (least resistance) and the front diff could not engage because the ring is jacked up.

That would explain why I see the front driveshaft spinning with no power to any wheels. And then why locking the center, I was able to move, because half of the power was sent to the rear.

Thanks for the help everyone. Hopefully the front diff is the issue. I am taking it back today.

You said you drove 70 miles on it correct? The R&P would be fine if you did that.

 

[JTS197]

You said you drove 70 miles on it correct? The R&P would be fine if you did that.

Yes I did. It was mostly on the freeway where I was constantly moving. It was only when I exited, and came to a stop, when there was no power getting to any of the wheels.

So, it still could be the CVs? I had replaced those about 2 years ago from AdvanceAuto; maybe they're junk?

 

[Inv4drZm]

Yes I did. It was mostly on the freeway where I was constantly moving. It was only when I exited, and came to a stop, when there was no power getting to any of the wheels.

So, it still could be the CVs? I had replaced those about 2 years ago from AdvanceAuto; maybe they're junk?

I'm still guessing t-case. It being stuck between locked/unlocked or something. Not sure. Good luck.

 

[JTS197]

I'm still guessing t-case. It being stuck between locked/unlocked or something. Not sure. Good luck.

Just to check, if on my old TC I can do a full spin on the input shaft and see both flanges turning, would that be a good sign the TC is ok or could there be something else inside causing it spin without engaging anything?

I had considered that too, but I do not know exactly how these TCs run.

Maybe I should just do a FJ t-case/front diff conversion! :madgrin:

 

[Inv4drZm]

Just to check, if on my old TC I can do a full spin on the input shaft and see both flanges turning, would that be a good sign the TC is ok or could there be something else inside causing it spin without engaging anything?

I had considered that too, but I do not know exactly how these TCs run.

Maybe I should just do a FJ t-case/front diff conversion! :madgrin:

Not sure, maybe? Try changing the oil and see if any metal comes out would be another easy check.

 

[rdruss]

This whole problem is very confusing (understatement). Wouldn't ATRAC be involved at some point in this scenario? It seems with the AWD system that regardless of what happens to the front diff there should still be some power going to the rear.(?)

 

[rdruss]

This whole problem is very confusing (understatement). Wouldn't ATRAC be involved at some point in this scenario? It seems with the AWD system that regardless of what happens to the front diff there should still be some power going to the rear.(?)

This has to be an electronic problem of some type. Remember the post about the guy who had replaced his horn with aftermarket and some time later out of the blue after filling up with gas his 4R died 60 ft. later and that was it until they discovered something about that horn and it overloading something that led to a failure of a power module or something?

This sounds weird like that one.

 

[JTS197]

This whole problem is very confusing (understatement). Wouldn't ATRAC be involved at some point in this scenario? It seems with the AWD system that regardless of what happens to the front diff there should still be some power going to the rear.(?)

I am not 100% sure how ATRAC works. If ATRAC is dependent on the ABS sensor and a wheel spinning, to determine if it needs to redirect power, then I don't think it would do anything because none of the wheels are turning whatsoever. The only thing turning is the front driveshaft. And to add, when I put it into Park, my 4Runner will freely roll; I would think ATRAC is out of the picture at that point.

My mechanic now thinks it's some control module around the steering column causing the issue?!?! I have no idea now. I tried to tell him I thought it was the front diff and he seems to think otherwise.

 

[rdruss]

Yes, as I understand it there needs to be a wheel w/o traction for ATRAC to get involved. I have an '07 Highlander, AWD, had it on jack stands with all wheels off and started it up, put in drive and the ABS had the all the brakes applying constantly, sounded like a calypso dancer and it almost jumped off the jack stands! Was very interesting. I thought this is what you did. You might try it just to see what happens?
Have not tried it with my 4runner, afraid it might just jump off the stands since it larger than Highlander.

 

[jbtvt]

My mechanic now thinks it's some control module around the steering column causing the issue?!?! I have no idea now. I tried to tell him I thought it was the front diff and he seems to think otherwise.

How does a steering column control module (which I've never even heard of) cause a loss of power to the wheels? This is your transportation, critical, time-consuming stuff. Try to get these part names nailed down. Pull out your phone, ask him to tell you whats broken again, and type it into notepad or something so you can look it up later and make sure you're not being fed a line of BS, which it sounds you are.

It also sounds like you need a new mechanic, even assuming no BS. How many trips in is this? Auto repair 101 - don't throw parts unless you know what's wrong. You don't replace a solenoid unless it doesn't move when 12v are applied to it, etc.

If your front driveshaft is turning and the front wheels aren't there is a malfunction in either the differential or both CVs (which seems highly unlikely). Where is the video? Upload it to Youtube and link here.

Drain the diff oil and check for metal, as was said already. Do this yourself. You're being taken for a ride by "your" mechanic.

 

[Mantilgh]

You say the front drive shaft was turning but no front axle? Was that by the power of the motor or were you turning the drive shaft by hand?

Sounds like front diff issue to me. I think the V6 has an actuator to activate the front diff and assumed the full time 4 of the V8 does not have it because it’s never off but I could be wrong


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[JTS197]

How does a steering column control module (which I've never even heard of) cause a loss of power to the wheels? This is your transportation, critical, time-consuming stuff. Try to get these part names nailed down. Pull out your phone, ask him to tell you whats broken again, and type it into notepad or something so you can look it up later and make sure you're not being fed a line of BS, which it sounds you are.

It also sounds like you need a new mechanic, even assuming no BS. How many trips in is this? Auto repair 101 - don't throw parts unless you know what's wrong. You don't replace a solenoid unless it doesn't move when 12v are applied to it, etc.

If your front driveshaft is turning and the front wheels aren't there is a malfunction in either the differential or both CVs (which seems highly unlikely). Where is the video? Upload it to Youtube and link here.

Drain the diff oil and check for metal, as was said already. Do this yourself. You're being taken for a ride by "your" mechanic.

Yeah, I am getting it back. This guy has worked on a few cars/truck for our family before without issue. I am not sure what is going on with him with my 4Runner.

I have been hesitant on working on it myself because 1.) I have not worked on major drivetrain components before and lack any experience troubleshooting it (except for replacing the CVs). 2.) I have 2 other "projects" in the garage that are not drive-able.

To add, my driveway is sloped.

Anyways, here the link to the video: Bad Front Diff Video



If you look to the right, you can see the front drive shaft spinning when I put it into gear.

 

[rdruss]

If you put it in park and it still rolls freely then that says its not in park for some reason. Mine doesn't roll in park, no vehicle should roll in park unless there is something definitely wrong, the trans not getting the message you are in park.
There have been vehicle recalls because vehicles rolled in park.

If this is so, there must be something wrong in the trans.

I'm really anxious to hear what you find wrong!

 

[Inv4drZm]

If you put it in park and it still rolls freely then that says its not in park for some reason. Mine doesn't roll in park, no vehicle should roll in park unless there is something definitely wrong, the trans not getting the message you are in park.
There have been vehicle recalls because vehicles rolled in park.

If this is so, there must be something wrong in the trans.

I'm really anxious to hear what you find wrong!

I've rolled in park before. Unlocked t-case does weird things under the right circumstances with driveshafts or potentially CV's disconnected.

 

[rdruss]

Yeah, with rear driveshaft disconnected I can see that, it would almost have to roll unless park brake on.