A340H transfer case chain help.

[DeclansDaddy]

Well after replacing a bunch of parts in my front end trying to diagnose a problem I have now found the culprit and it turns out it's in my transfer case.
What you are looking as is the chain with enough slack that it's lying on the bottom of the housing. I knew pretty quickly into the teardown that my problem was most likely here when I pulled the drain plug and not a stich of lube came out. I can actually turn the trans gear while keeping the chain completely off of the front drive gear all the way around. This has been my popping sound, or I'm at least 99% sure this time. Question is does anyone make a replacement? I've googled it and come up with nothing. These trans came in the ADD vehicles so going to a yard might just lead me to a bunch of wore out chains as well since they are turning constantly. Opinions on my next move?

 

[DeclansDaddy]

Here's another pic showing just how much slack is here. This can't be normal.

 

[DeclansDaddy]

The more I am digging into this the more I am getting conflicting info. The tag on the trans says its a A340H, which I'm seeing is the only model with 2 drain plugs which mine has. But everything I am seeing showed a hard line coming from the front of the trans to the rear of the chain case however mine does not have that at all. I'm so confused. I thought the A340H had the integrated transfer case which cant be taken apart but it seems someone may have put a different transfer case on my trans, or at least the chain housing. Are the A340H chain housing lubed themselves by Auto Trans fluid or is it a separate housing all together that gets gear oil? Tomorrow I guess I'll crawl under my old 95 and see what that looks like as I was under the impression they both had the same transmissions. Man the 5spd swap gets more logical everyday!!!

 

[KidVermicious]

The trans that would have come stock with your '86 is the A340F. You say the one on there now came from a second gen, so that should be the A340H. The easiest way I know to tell the difference is to look for a mechanical shift linkage on the side of the tcase - if it's there, then that's a VF2A transfer case which dictates an A340F transmission. If there's no mechanical linkage, then it's shifted internally and it's an A340H trans.

I suspect you may have the A340F there, because I don't think you can pop the tailhousing of the A340H's integrated transfer case like that? Either way, I agree that your chain is stretched way out of spec, and depending on how long it's been run like that the cogs on the bearing shafts are likely rounded as well. It's not a question of can you fix it at this point, but should you. These trans/tcase combos are reliable enough that I think you could reasonably trust that a junkyard tcase would be in good shape, and that's definitely a better option than tearing yours down and trying to source parts to fix it. Another option is to swap to a manual, and you know that's what I think you should do. Start collecting parts (or better yet find a parts truck), and in the meantime button up your tcase and run it. Think of that slipping chain as a custom center diff. :thumb:

 

[DeclansDaddy]

Another option is to swap to a manual, and you know that's what I think you should do. Start collecting parts (or better yet find a parts truck), and in the meantime button up your tcase and run it. Think of that slipping chain as a custom center diff. :thumb:

That's what I'm leaning toward. I reached out to my yota part hook up guy to see what he's got lying around. Hopefully he'll get back with me soon. In the meantime I'll just slap her back together and roll with it. I'm going to snap some pics with my good camera today of what I got under there because even though I'm planning on ditching it is still like to know what I have in the truck and maybe I'll be able to sell the trans for a couple hundred bucks anyway. Everything to me points to the 340F except there are 2 oil pans. But all the 340H I've seen have the hardline running to the chain case cover (cooler line I guess) but mine doesn't have that. I guess I got a Frankenstein transmission. I'll post up some pics in a bit and see what everyone thinks. It's a shame because the transmission shifts awesome. Maybe someone will want it for something.

 

[KidVermicious]

Did a little fishing on Google image. This is a passenger drop VF1A.

This is an A340F with a driver drop VF1A tcase on the left, and an A340H with a passenger drop integrated tcase on the right.

Note the vastly different tailhousings, and the lack of a shifter mechanism on the A340H tcase - you should have no trouble glancing at yours and IDing which you have.

 

[Scalded_Dawg]

KidV - the second pic, no worky...

 

[KidVermicious]

That's odd.

Here's the url: http://www.4x4wire.com/toyota/tech/autocrawler/2trans_01.jpg

 

[RiFF RaFF]

That's odd.

Here's the url: http://www.4x4wire.com/toyota/tech/autocrawler/2trans_01.jpg

The owner of this website (Recent blog posts - 4x4Wire) does not allow hotlinking to that resource

 

[DeclansDaddy]

Ok so I've learned a lot today. and took some pics. I crawled under my 95 as well as a buddies 94 3.0 truck and both of those indeed have the A340H. Which are ID'ed by (1) the 2 trans fluid pans, (2) the 30-80 LE tags on them and (3) the transfer case coolant lines coming from the chain case. Now its been said that the transfer case on the A340H are integrated and cannot be removed however yes while they may be integrated as the only way they will function is on the back of the A340H trans, physically they are not mated. They can be removed from the transmission housing. This is a pic from under my truck but the other 2 setups are identical.

I think they call it integrated as the transfer case and transmission share fluid and one without the other will never work. So its obvious to me I indeed have the A340H with the proper transfer case. However it gets a little weird where the chain case bolts to the TC. Both the other trucks I looked at today have the chain case with the cooler lines attached but mine doesn't. Here's a pic of my chain case with the cover just mocked up for photo purposes. There's not even a place the fluid lines could of been removed.

So it appears to me, and I plan on putting something on Yotatech to see if I can get it confirmed, but it seems the from the bellhousing to the rear of the transfer case is a A340H and is identical to this point to my other reference trucks but it looks like someone then put the chain case off of a A340F onto it which doesn't require the cooling lines, maybe because in the A340F the fluid isn't always moving in the chain case as like the ADD vehicles. And what I think happened in my situation is, and correct me if I'm wrong but in a A340F the chain case is filled with gear oil to the fill plug and the A340H Auto trans fluid is circulated through the chain case lubing the chain, so maybe the PO was under the impression that with the newer style transfer he wouldn't need to lube the chain case because like I said there was not a drop of oil in it when I pulled the plug off of the rear chain case cover. Which is probably why my chain is so loose. I'm thinking a PO got a trans froma 2nd gen, noticed the cooler lines and all on the chain case and just swapped his old chain case to the new trans. Heres a few more pics for ya to glance over in case you see something proving me wrong.
This is Drivers side of chain case. Its just mocked up there hence the gap. Notice the excessive use of high temp red which is also around where the TC meets the chain case.

This is drivers side where trans and transfer meet. Linkage is on the TC.

Passenger side of trans

Bottom of trans. Ive been told by many that the 2 oil pans means A340H

 

[DeclansDaddy]

Holy crap I need to learn how to resize my pics. Sorry.

 

[mikekfr]

Just ran across this, it's in your neck of the woods.... Toyota 4Runner Auto trans

 

[DeclansDaddy]

It's been deleted. But I think I saw this and he wanted $500. I'll just do a 5spd swap if I'm spending that kinda cash. I think I know who had it. See a guy on 757toyotas FaceBook doing a swap too.

 

[Scalded_Dawg]

757toyotas FaceBook

Oh man.... You follow that group? I had to leave about 6 months ago, couldn't take the immaturity any longer.

 

[DeclansDaddy]

Oh man.... You follow that group? I had to leave about 6 months ago, couldn't take the immaturity any longer.

Haha yea I can see that. I just like chatting with the classic guys. Pretty much a bunch of FJ mall crawlers mostly.

 

[02SE]

It could be worse..

 

[DeclansDaddy]

It could be worse..

Yea that's not good. But if my problem was that obvious it woulda at least saved me $250 in front end parts lol.

 

[DeclansDaddy]

Alright. 1 more question about the A340H. The chain case is lubed by ATF. Does the transmission feed the ATF to the chain case or would I have to fill it seperately with the fill hole?