snap-on

Ok so when i had the motor I also had the trans out. i cleaned the filter and everything, had it upside down and backwards.

i never pulled the plug or the pan off the transfer case thats attached, but did pull the lines that lead to the cooler thingie hanging off the back.

so i thought the 2 halfs share the same fulid no?

if thats correct, and you fill up the trans dose it fill up the xcase also?

I notice a fill plug on the back of the xcase and will be checking it when i get home, just trying to trouble shoot why the xcase doesnt understand what 2H is.

regularguy412

Here's what the FSM has on the subject:

Pull the drain plugs on both pans. Refill BOTH from the tranny fill-tube.


Mike in AR

leebee

if your tcase has a drain and fill plug, filling from the trans dip stick tube will not get atf to the tcase. you will have to fill the tcase from the fill hole. having said all that, that is what i had to do when i changed my fluids and it took several tries at the stealer to get the correct information. verify with the stealer by using your vin and a visual check to ensure trans type and tcase. my 93 runner uses atf in the tcase which is mated to the a340h auto trans.

lee

InternetRoadkill

The xfer case is filled seperately from the tranny. Fill it until the fluid begins to drip out of filling hole.

regularguy412

http://personal.utulsa.edu/~nathan-b...28operatio.pdf

There is no separate fluid pump for the transfer case. The A340H is hydraulically actuated. The fluid pressure to drive the transfer case valvebody is delivered by the pump in the transmission. Therefore, it is not necessary to fill the transfer case from below. Although, I suppose it can be done that way.

Mike in AR

InternetRoadkill

Not true. There is a pump in the transfer case and it has its own filter as well. The FSM specifies that the xfer case must be filled as indicated above (About 2 qts).

regularguy412

I stand corrected. The FSM does later state to fill thru the filler hole in the transfer case.

Mike in Ar

dstrick32

I've drained and changed both trans and tranfer and hve never refilled transfer from underneath and it still works and fills up with fluid from the tranny dipstick. 1994 Toyota Pickup 3.0 A340H automatic!! Tell me how it get to the transfer case??

snap-on

there is what i would call a fill plug on the back of the transfer case. 24 mm just like all the other fill plugs on yota drivetrain...

i took it loose and pumped at least a quart of ATF into it untill it ran out like any other drivetrain oil fill you do.

regularguy412

The tranny AND transfer case can BOTH be filled by using ONLY the tranny dipstick fill tube.

How do I know this? Last Fall, around October, I drained the pans on both the tranny and transfer case on my 92 3.0 A340H-equipped 4Runner. I didn't take out the sight-plug on the back of the transfer case to refill it. I put ALL the fluid in thru the tranny dipstick. I have driven my 4Runner since then with no transfercase issues.

When this thread came up last week, I posted a portion of the FSM related to draining and refilling the A340H tranny/transfercase. It IS true that the FSM 'does' state to refill the transfercase from the sight-plug hole.

I had the opportunity to chat with one of the transmission techs from Marlin Crawler. I told him what the dilemma was and that I couldn't get the sight-plug outta the transfercase to fill it, but that I put all the fluid in thru the transmission fill tube.

He said,'Well, why not just pull the drain plug on the transfercase and see if there's any fluid in there". If the transfercase is full, don't worry about it.

This morning, I pulled the drain plug on the transfercase ONLY. About 2 1/2 quarts of tranny fluid drained into the container. Remember last fall, I ONLY put fluid in thru the fill tube.

I am now CERTAIN that the A340H can be completely refilled by using ONLY the transmission fill tube.

Mike in AR

Marc

If the transfer case can be filled using just the tranny dipstick tube, then how come when you drain the transfer case only a couple of quarts of fluid comes out and not the contents of the transmission?

trythis

I am going to guess: The fluid is pumped into the transfer case.

regularguy412

Right. The reason the tranny and transfercase can't be separated from one another is because the transfercase clutches engage by hydraulic pressure , just like the tranny clutches. The hydraulic pressure has to come from somewhere. The FSM lists the Front Pump ( the one in the tranny) on the overview page. However, it does not list a separate pump in the transfercase. They share the entire volume of fluid. However, the fluid is contained in two, separate pans.

The reason only 2.5 quarts come out of the transfercase is because that's all the fluid that is contained in the transfercase pan (engine off). The tranny and its pan hold the balance of the fluid. I suspect that if you started the engine with only the transfercase drain plug pulled, more fluid would run out, because the fluid from the tranny would begin to be pumped into the transfercase.


Mike in AR

InternetRoadkill

Ever wonder why there are coolant lines coming from the xfer case? They come from the pump inside the xfer case. The xfer case also has its own valve body assembly. It receives pressure signals from the tranny.

While it's true that you can fill the xfer case by using the dipstick tube, it's not a very good idea. You risk burning out the friction plates by starving them for fluid and fluid pressure. The xfer case is partially open to the inside of the tranny, but there are a number of dams preventing the fluid from directly filling the xfer case from the tranny. The xfer case will fill *eventually* from the fluid being pumped from the tranny into the xfer case's valve body. But why risk damaging it? Take the plug out and fill it. It's only a quart on a refill, and 1.9 qts for a dry fill.

Marc

Ok, I think I may have this controversy solved.

When I first bought my truck I picked up both a Chilton and Haynes outhouse manuals. Both of these manual indicate that to change the transfer case fluid you have to remove the drain plug at the back of the transfer case and refill with about 1.2 qts using the plug just above it.

THEY ARE WRONG. The instructions and pictures are for the TRANSFER CHAIN CASE.

Since then I picked up the FSM but never bothered to check out the correct procedure till recently.

The FSM says to drain the Transfer Case Pan using the drain plug on the bottom of Transfer Case just behind the transmission drain pan.

It also indicates that the transfer case will be filled from the dipstick.

What do you guys think? Am I on the right track?

GSGALLANT

OK... let's be careful what we share for info if we're not sure so that people don't trash their transfer cases.

The transfer chain case (at the very rear of the transfer case) on an A340H drains and fills independently of the rest of the transfer case and the transmission. You change the fluid in the chain case by opening the large drain and fill plugs at the very rear of the transfer case (these two face the rear of the vehicle). You can change this fluid (approx 1.2 quarts) without draining the transmission and the rest of the transfer case.

When you want to change the transmission (and the rest of the transfer case) fluid, you remove the two small drain plugs (one on the large transmission pan and the other on the small transfer case pan). Let the fluid drain out (around 5 quarts or so), re-install both drain plugs, and re-fill through the filler tube. Yes, this will get fluid into both pans... more specifically, the fluid will overflow from the large pan into the small pan after you get approx 3.5 quarts in there. (I started refilling mine with the drain plug not re-installed on the small transfer case pan just to ensure that it would also be filled.)

...and no the transfer case does not have its own separate pump.

Marc

GSGALLANT - you said it much better than me. thanks.

GSGALLANT

No problem... there's lots of confusion about the A340H transmission. It is more complex than most other Toyota transmissions.

Jason Horton

i have been reading this forum for the past few weeks on everything i need to know about my 95 4Runner I just bought about 2 weeks ago. First off let me say this....YOU GUYS ARE AWESOME!!!! My particular truck has a 3.0 and a A340H tranny. Since I just got the truck I have started some preventative maintenance on it before I go wheel'n or hunting. My question is that I just did a tranny filter change with fluid but I didn't drain the trans. case at the same time, so did I just waste my time and just add SOME new fluid to the previous nasty that is in the trans. case or does it mix slow enough I can still change the trans case fluid without getting all that old ATF mixed in? I have only drove about 1.5 miles since I drained the fluid and filter. Please help...I hope I am ok so far. P.S. I put 5 quarts of ATF in and it is still reading low. How much fluid should it take?

scope103

You're worrying about the wrong thing. When you drain the ATF from the transmission, about 6 (that's right 6) quarts of the fluid stays in the torque converter. The drain-and-refill capacity is nominally 4.8 US quarts, but the total capacity is 10.9. http://kai.supramania.com/Supra/A340...%20(RM216).pdf

So at best you'll end up with 40% new fluid. If you're worried that the old stuff was "nasty," then drive it 100 miles and change the fluid again. Then you'll replace 40% of the 60% of the "nasty" original fluid. So don't go nuts; it will take about 15 drain-and-refills to replace the majority of the fluid.