I have posted this same issue on T4R, so I apologize for those of you who frequent both boards. Need some help here...

On the way to Gramma's house Christmas day (no joke), on an icy dirt road. Going about 20 mph in 2WD, and the rear end got loose. We spun around, and the rear driver side hit the ditch first. Luckily, it was a pretty flat ditch. The engine stalled, however.

Back on the road, it's driving fine. I decide to put it in AWD (push button on stick), and within a few seconds after engagement, there was a fairly nasty grinding sound from the mid-front area underneath. Took it out of drive, then pulled the stick back into 4WD. It went in, but the grinding and ratcheting continued. Not constant, but on/off.

Drives fine in 2WD. Got to Gramma's, played around with it a bit in the driveway, and the problem is still there. I haven't had any issues whatsoever with AWD or 4WD in the 5 years I've owned it, and I use it at least once a month, if not more in the winter.

Here is a video with sound:
Thoughts? Front diff? Transfer case? CV axle?

Thanks!

 

Is the actuator jammed? It sounds like something is not liking being engaged or trying to be.

How does the fluid look?

 

Noticed that the grinding sound is not continuous so maybe a moving part hit something hard and got damaged maybe bent or displaced. It makes the grinding sound then when it makes improper contact with another part

 

Rear diff lube came out OK, replaced with new. Front diff lube I had to suck out, because drain plug is stripped, but it came out OK...just dark. The transfer case lube came out perfectly silver...a pure mix of very fine metal particles. No big chunks, though. I replaced with new 75W-90, and the problem remains.

Yes, seems to me the engagement is not fully happening. The dash lights operate as they should (they stay on, and turn off when they are supposed to), and I can hear what sounds like solid engagement in and out of AWD or 4WD. So, it seems like the actuator works, but maybe it's not traveling all the way?

 

Gear lube that looks like silver paint says that she'll likely have to come apart for repairs.
Bearings and gears that have had those steel particles run thru them, are never the same.

 

I'd take a close look to see if the shaft is bent.

As millball stated if the old fluid was silver, then something internal is not working correctly. You may want to take it to a transmission shop for repair or hunt for another working one from a junkyard.

 

I understand that silver lube isn't good. But it has been functioning perfectly up until last week...and when I changed lube a few years ago, it was fine (dirty, but not silver), so I have to think the particles are due to the recent grinding (which has been minimal, only to get video of it). So I'm hoping not everything is trashed in there.

J2F42C - what shaft are you referring to? THe front propeller shaft - where the two halves meet - looks to be fairly rusty, as if it hasn't moved back and forth in a long time (unlike the rear shaft at that same spot)...could it be the front propeller shaft is stuck in limbo?

Thanks!

 

The front drive shaft does not have travel, since the front differential is bolted to the frame. Collapsing the two-piece shaft is necessary when removing the differential.



Andreas

 

That makes sense! Thanks.

 

I'm about to buy a used transfer case and hope it solves the problem. I'm still skeptical, though. What else could possibly be going on here, if it's not a problem inside the t-case?

Let's say the front diff was fubar'd. Would a bunged up front diff (broken ring gear, etc) cause the front driveshaft to stop spinning (jam), and create enough of a jolt to the t-case to make the noise I'm hearing? That's the only other thing I can think of.

Today I'll get the truck up on stands and put it into 4H-L. With no friction on the tires though, I'm not sure it would be a fair representation.

Out of ideas...

 

FYI - t-case from a donor has been installed, and is working beautifully. Someday when it's not -20F and I have nothing to do, I'll take apart the old one to try to figure out what happened. Until then, I'm happy with the "new" t-case.

 

Good to hear.

When you get time and the weather isn't abysmal, check the actuator first. I know this isn't one for the third gen, but I would imagine Toyota wouldn't deviate my from the 3rd to the 4th:
http://www.toyota-4runner.org/4th-ge...acement-2.html