Ah OK, I hadn't fully viewed Timmy's all 3 vids for the transmission removal, but that's also good to know, lol. I'll support the back of the engine with a jack while doing this.

EDIT: I'll review the vids this week and see if anything else stands out. I appreciate it!

Just a quick update, I've placed about 4,000 miles on the truck and it's been about a year since I noticed that whine (at 4k/yr you can imagine I don't drive it much. I've been making it a point to do some overlanding and camping to rack some miles on it).

I replaced the fluid and filter when it it started making the whine a year ago (no debris or issues). I've noticed in the last ~1000 miles the whine is pretty much gone. And it's no longer making any noticeable whine in R or D at idle. There is a slight "something" when accelerating up to about 30 mph, but it's like 1/20th the loudness of the original whine. Barely noticeable. (and that could be the supercharger). I'll keep observing it, but it was strange how it appeared kind of out of nowhere, then is now slowly going away.

Also, trans feels exactly the same in every way as it did when I bought it, both now and when the whine first appeared.

PS-Finally got around to building a cargo shelf from scratch, really motivated me to actually go camping, but boy does it add weight, lol.

Attached Images

   

I absolutely hope it does clear things up forever.

I too did a full fluid exchange and new filter - and the whine did decrease substantially after a month or so and I too would only hear some minor whine on accelerations. Now mine had a lot of tiny metal debris so we know something was wearing fast. I should have changed fluids sooner - waited too long - like 100K - my very bad.

This went on for about 2+ years then it began to whine only when I used OD off (climbing smallish hills) until one day it got somewhat loud and I began to feel/hear what sounded like marbles for a few seconds at a time and then would go away - trans worked as normal all this time. The marble sound came more and more often and once or twice would even shut the engine down at stoplights so I decided to drive it to a nearby friends house to park it.

6 months later a rebuilt arrived from Yota1 out of Riverbank Cali and it has been Heaven ever since.

I think your OD/issues may have been related to the planetary gear problem on the 01-02:

there are more instances of failure of the planetary gear of the 01/02 transmissions. they are not the same trans that was used in 99/00 - which do not have as high of a failure rate. the electronic controls are different along with the valve body and some other internals IIRC.

*****
it happened to me in my old 01 4r at 113K. as far as im concerned it is a problem.

the difference is that they used a smaller thrust washer or something that allows movement. so as it wears down, it eventually lets go, causing the planetary to give and an implosion of metal occurs

*****
Yes I have read too that the planetary disk is weaker in the 01&02 4WD trans (Supposedly there is a difference between the 4WD and 2WD trans, I haven't asked around to confirm this yet.)
My Stepfather has a 2002 Sports Edition 4Runner 4WD, at 124K the planetary disc for the Overdrive failed, leaving him and my mother stranded 200+ miles from home :-D
Toyota has not announced this as a recall problem since there only seems to be a limited amount of 4Runners.
Some people have been lucky and there transmissions have lasted just as long as any other year, so its really up in the air.

I'll just plan to keep an eye (or really ear) on it. Your symptoms are helpful so I know what to look for just in case. It's just weird that it happened so quickly, the pan and magnets were pretty much pristine and the fluid looked great.

It did take 3000 miles of driving (which was about 2-3 road trips) for the whine to pretty much disappear. At first I thought it my imagination, but as I started looking out for it, I realized it was all but gone. And now it's been 2k+ miles and not noticeable really. Before you couldn't really talk at Idle to 40 mph cause that whine would be in the background.

Now it's silent at idle and almost not present (I'd say tbh, that no one else but me would notice it, while before it was quite noticeable) going up to 40, past 40 you don't hear anything. Going into/out of OD doesn't make a difference, still quiet.

With the age of these and the fact I plan to keep it forever though, I thought about sourcing a rebuilt trans and new TC and just storing it. But that's maybe my OCD tripping.

Before taking it all apart would you consider a premium lube (like Royal Purple) in the transfer case (its small volume)?and if no noise improvement then do the same for tranny/torque converter. Or perhaps an additive to the tranny/torque converter?
Amsoil makes great claims for their lubes.
A member solved Torque converter shudder with the additive Lube Guard.
My 2 cents

Attached Images

 

if you ever have to do the trans or anyone else, there is that tool to support the engine in these cases. really simplifies the job of replacing a transmission or any other job where you are playing with engine or transmission mounts, on any cars.

https://www.princessauto.com/en/1100...t/PA0008668048

Just to chime in - my AT is still whining in all but N and P (been whining for 3+ years) . Never missed a shift or slipped. Very few particles on the magnets when I did a filter change recently......

Even after fully warmed up, it will still whine in R/D? Does it also whine while accelerating?

That's exactly what I was expecting, that the whine would continue, but now even in cold starts it's barelu audible at idle (and all but gone after warmed up). How many mile ahve you put on it in 3 years?

The whine/strain noise never goes away in any forward gear or R.. Put about 25k on it. Here is a little clip of my particular sound. Rather alarming when it first showed up!

- YouTube

Well good to know it's been 3 years and 25k and still shifts fine. I'm at around 5k but with the noise pretty much gone within the past 1k miles. I'll try to record mine as well to be sure.

Ever tried to change out your filter and fluid to see if that makes a difference. I did replace mine a year ago (5k miles ago) but honestly, the filter and fluid looked fine, but I guess you know never if there there's some really small particles clogging it.

Yes I did the internal strainer* recently and a forum member said the magnets looked pretty good. I have done numerous drain/fills over the years, too. I just got back from a 1700 mile road/offroad trip and survived....

*Which reminds me that I bought both versions of OEM strainer because on a 2000 it's not totally clear which one is needed. If someone needs the 'other' P/N strainer, I have one in the dealer bag I'll give away for the cost of shipping and a beer.....I believe I have a thread on here with photos

I'll probably end up getting this A340F Yota1'd when time and money coincide.