Help needed tonight - truck stuck in 4WD :(

[aowRS]

I'm leaving very early tomorrow morning for the beach and finally have an issue with my trusty 4Runner that I need to ask for help on. It is stuck in 4WD and apparently the center diff is locked as well. I've attempted everything and am about to crawl under the truck to see if there's anything obvious.

This happened at the same time that I accidentally nudged the 4WD lever into neutral while the truck was slowly driving in "D". Instantly the four illuminated wheel icons, as well as the center diff light, started flashing. I've read numerous write-ups this evening involving the testing of switches and actuators - but frankly I will not have the time this evening.

Is there something easy that I may be overlooking? I have the battery disconnected at the moment. This was to be the first time that I took the truck onto the sand at Assateague Island, VA. I figure after covering 151,000 trouble-free miles since buying it new, it was time to reward it!

I look forward to any and all responses. Please keep in mind that my truck is a 2001 with multi-mode 4WD.


Andreas

[aowRS]

Problem solved - I think! :thumbup:

I went out to the shop and raised the truck onto four stands (the battery had been disconnected for at least 30 min.). Then I gently tapped the vacuum actuators with a small hammer and thoroughly checked each electrical & vacuum connection. The first thing I noticed when the rear came off the ground was a distinctive 'thud' in the driveline. I then lifted and supported the front, re-connected the battery, and turned the key to the first position. The flashing 4WD indicator was gone. So I started the truck, clicked it into 'D' and gently gave it a bit of gas. It was definitely in 2WD. From there I switched back and forth between 2WD & 4WD at least 10 times, allowing the wheels to stop first and with the tranny in 'N'. It worked each time without fail. The center diff lock switch also works as before.

So my simplistic theory is that something was bound in the transfer case when I accidently nudged the lever into 'N' (while rolling in 'D').

What a relief! As long as the over-sand area is open tomorrow, the truck will finally get a chance to romp on the beach (no saltwater BS of course...).


Andreas

[fustercluck]

This happens with other more primitive 4wd systems too. What happens is that the 4wd gets bound up with differential pressures. Once the pressure is relieved, the transfer case can slip into and out of gear. I suspect that what you did by lifting the truck off of the wheels was to relieve that pressure and allow the actuator (rear) to disengage. I'm unfamiliar with the center lock system, but logically it seems that the relief was cascading and allowed the center lock to disengage.

That thunk sound is what I'd occasionally hear from my e-locker when it disengaged under torque.

[aowRS]

That sounds logical. Let's see how the beast does tomorrow. I'll post a follow-up.


Andreas

[fustercluck]

Parenthetically, the same thing happened to my 2nd gen truck once. I eventually had to drive it onto some loose material amd rock it back and forth a couple of times to get it out of 4wd

[YotaFun]

I have had this issue with stepdads 02.
Pretty much fuster hit the nail on the head with this one.
Just a matter of getting the pressure releived.
I know when my 97 is stuck in 4wd I have to play with it a little, sometiems have to drive a mile or two and let the truck coast to a stop helps it.
That thud was probably the center diff unlocking and the pressure being relieved and getting you back in 2WD like Fuster Mentioned.

Good lUck and have fun on your trip tomorrow!

[Bob98SR5]

andreas,

hey, good to see you posting here again. hows the porsche? :)

bob

[tulsa_sr5]

Glad you got it fixed! Had an idiot do pretty much the same thing in my 97 on a test drive, wouldn't listen to me about taking it out of 4 before he tried to turn around in a culdesac. Took a bit of straightline forward and reverse to free up the driveline and shift back to 2wd. Same idiot offered my 4k for it later and insisted he was being generous.

[aowRS]

andreas,

hey, good to see you posting here again. hows the porsche?

bob

Bob,
It's doing great - absolutely no issues and we've taken it on numerous lengthy trips. A keeper for sure. :)

The 4Runner did great on the sand - no issues with the 4WD whatsoever. I found the ideal tire pressure to be around 15 psi and have ordered a set of Stauns for this coming weekend...

Here are a few pics:

http://img.photobucket.com/albums/v452/aowalter/4Runner/beach3.jpg

http://img.photobucket.com/albums/v452/aowalter/4Runner/beach2.jpg

http://img.photobucket.com/albums/v452/aowalter/4Runner/beach1.jpg


Andreas