thezentree

Hi all,

I have a new-to-me 2001 4Runner, auto transmission and that stupid pushbutton 4wd. I'm trying to figure out why it doesn't always go into 4wd on the first try.

I've found that if it won't go into 4wd (high or low) and the dash indicator starts flashing, I can typically get the vehicle rolling with the transmission in drive, shift the transmission into neutral, and then back into drive. I'll hear a clunk or two, the truck will lurch like it's going into gear, and then all is well. This is shifting to 4hi, 4lo, or 2hi. Sometimes it goes straight in. Center diff lock will work without issue.

This afternoon I got it into a sweet spot, where with the vehicle stopped and transmission in Neutral, I was able to shift in and out of 4hi and 4lo a bunch of times without problems. It was like all the gears were lined up perfectly. As soon as I put the transmission in gear and moved the vehicle forward, it went back to fighting me to get it in or out of 4wd.

I read that long thread about the switches on the t-case and front diff that can go bad and cause the truck to stick in 4wd, but I don't think that's my issue since it will eventually do what I ask it to.

I also noticed that a lot of times after it finally does go into whatever gear, I hear a buzzing from under the dash for a few seconds, then a small clunk somewhere under the truck. It sort of sounds like an electronic vacuum pump running, but I don't think this model year has vacuum-actuated anything in the 4wd system?

Anyway, has anyone encountered something like this? The only thing I can figure is that maybe the actuators are sort gummed up from lack of use (I bought it from my sister who probably hadn't used 4wd in the better part of a decade), but from what I've read, the actuators aren't cheap to replace, particularly the t-case actuator. At this point my next step is to change the front diff oil and t-case oil. Any insight here would be greatly appreciated.

RDubyota

I have a 99 4RNR and mine clunks pretty bad if I am on a incline and shift it into 4HL (I never use the push button 4H). I found that if I am in a slow roll or more it shifts in like butter. As far as tearing it down and cleaning/changing the fluids....I would do it just to be sure of what you have. I personally change all fluids on every vehicle I buy just to be sure, even if the seller says it has just been done. I trust sellers and dealers about as far as I can throw them.

On the vacuum system...couldn't tell you on your year, but mine is all electric. Hanes or Chilton manual should tell you.

thezentree

Oh I don't mind the clunking, every 4wd I've had has done it in some form or fashion. The fact that it sometimes takes a couple tries to get it to successfully shift is what concerns me.

wyoming9

iTrader: (1)

I would have to agree your problems may just be from lack of use for so long.

Who can say if the problem will be cured by use or if things need to come apart

TheDurk

The 2001 is definitely all-electric.

Your '99, however, uses vacuum in the front ADD system, but not the TC. Trust me, I own one.

Don't trust anything that Haynes or Chilton says about year-to-year stuff. Frequently wrong.

thezentree

That agrees with my (limited) reading on this 01. I think the buzzing I heard is that weird electronic master cylinder this thing has. I just had to move it and noticed a very subtle bump in the brake pedal when the buzzing quit.

RDubyota

I had no idea, don't remember reading about it in the owners manual....may not be listed. I am rather new to the 3rd gen world, and this is my first 4RNR. I had a '82 pickup, so it's mechanics were pretty straight forward, I didn't need much guidance with it.

I have not had any problems with Haynes (however I have not purchased one for my '99) and I haven't bought a Chilton's in 10+ years. I know there is probably a section in the forum somewhere that covers this but I'll ask anyway. Would I be wasting my $ with either of those manuals? If so, what manual do you suggest?

RDubyota

My owners manual (lucky to have the original) says that if the indicator blinks when shifted, while not moving, to either move fwd or reverse. And if moving to slow down or stop. Mine gives me the blinking lights from time to time and I have not had to stop once. All I do is let off the throttle slightly, and she finds home. I rarely shift from a stand still, unless I need 4L. I'm not the kind to try something in 2WD if I know I am eventually going to need 4WD anyway. I just drop it in and leave it.

I have only had the RNR for about 2 months though so I am quite a novice with this system. I thought it was odd too when I got the blinking light but apparently it is supposed to do that. I guess the weirdest thing for me was not having to shift in and out of 4WD in order for it to go in. I'm used to having to bend it to my will.

Anyway, hope that helps with the blinking light question. I still would change all fluids just in case. If nothing else, you'll know what you have and how many miles/hours you've had it.

TheDurk

I actually have both on the shelf, and I haven't touched either one in over ten years. They were never very specific as to model, let alone year. I spent the coin and got the FSM for my year in paper. Paid for itself many times over.

And yeah, the OM will not tell you if your front diff is vacuum, electric, or liquid sodium activated.

thezentree

Yep, that's the plan for this coming weekend. That and LBJs. We'll see how that goes.

RDubyota

Thanks Durk...Looks like I will be investing in a FSM then.

Zen, Let us know how it sounds after.