4WD Front End Vibration - like a rumble strip ??

2011 V6 Auto TRD O/R - No lift - 95K miles.

Ok TW Internet Technicians....need your help.

Searched some with no success.

So I was driving around town tonight and on the interstate during some light but slippery snow. Left my house and put it in 4WD as secondary roads were slippery...all was fine.

Got on the interstate and turned off 4WD as plows had the road cleared nicely and the speed limit was dropped to 45mph....all fine.

Pulled off the interstate and engaged 4WD again as the secondary roads were again slick, but only 2" of snow max. I pull into a small shopping plaza to grab a coffee and as I was driving through the parking lot (5mph) to look for a place to park, the front of my truck started vibrating/shaking like I was driving on a rumble strip. I disengaged 4WD and it went away. Initially I thought I may be driving in plow truck or front end loader tracks...ugh.

Re-engaged 4WD again and same thing...went away after turning off 4WD. At this point I hadn't noticed if my 4WD light was blinking it not as I was so focused on the shaking/vibrating.

Now when I try and engage 4WD, it starts doing it again, but my 4WD isn't fully engaging (the light stays blinking). Tried it a couple of times and same thing. One time there was this quick grinding noise (kinda like when you try to start an already running vehicle). I shut 4WD off immediately.

Even messed around with 4 low in neutral and my truck would barely move. Disengaged again and it's fine.

Any ideas on what the issue may be?

Driveshafts lubed every 5K miles and I've changed T-Case fluid every 30K with Mobil 1. T-Case done at 90K and driveshafts lubed 500 miles ago.

Any insight is appreciated.

 

Dang that's weird. Did you try looking underneath for anything out of the ordinary? Not sure, bump for help.

 

To dark, cold and snowy to look last night. Still cold & snowy, but I'll bundle up a little later to take a peak.

 

Hoping in the light may help. Very odd, how many miles do you have?

 

Maybe the 4wd system is not fully engaging? Check to see if your 4wd indicator light is solid amber (or whatever color) or if it's flashing. Can you hear any loud clunking when you flip it into 4hi?

 

It was engaged during the time of the incident...now I can't get it to engage. No clunk. Feeling like it's trying to and I get the vibration.

 

95K

 

Check to see if anything is leaking from your tcase.

 

Yes, I'm planning to do that when I go out to shovel in a little bit.

 

Not that I know much at all about this stuff, but I'll check front drive shaft to see if I can spin it freely by hand.

 

I would look around too and see if anything affected alignment for it in someway too. Perhaps snap a couple pics for us to try to help.

 

Don't think it's alignment related as everything is just fine in 2WD.

It's 19 degrees with freezing rain now. I'll try and snap some pics.

 

That shaking/vibration while 4WD was engaged concerns me more than the not engaging now. But I'm sure it's all related.

 

That's my thought too but seeing how sensitive these systems can be sometimes hoping maybe something is causing an alignment issue like something rusted or something. 19 is cold be Careful it's 20 here.

 

Totally stressing me out. We have another snow storm coming on Christmas. Need that 4WD up here in winter.

 

Yah, I'm taking it to my dealership. I've had all positive experiences there and they always treat me fairly. I'll bring in some gear lube as I'm sure they'll inspect the T-Case.

I think they're open today...may go down and get an Appt.

 

Keep us posted

 

Interested in the outcome Sig.

Do you do the 10 miles a month in 4 wheel for lubrication?

 

I use 4WD often, so I don't use that approach. But if I go bit without using it, yes, I'll put it in 4WD for a little while.

 

So I just slid under (literally) and snapped a few pics. No leaks I can see on Transfer Case. I only see some splattered gear lube from when I did it 500 miles ago. However, I'm not able to freely turn my front driveshaft. Does that help narrow down the issue?