ATF getting into transfer, what to do? (1 Viewer)

[RockDoc]

I've suspected for week that the seal between my AT and transfer is going (oil weeping out around the L4 and position switches), and confirmed it today. A quart and a half or two quarts of fluid came out when I pulled the transfer fill plug, and it looked and smelled more of ATF than gear oil. When I pulled the fill plug, it seemed that there was some vacuum in the case.... (I can feel that the cap on the breather moves loosely, but I don't know if it is working as a one way valve and allowing a vacuum to build as the transfer cools...) So I need some advice on what to do short term.

For the short term:
Does this mean gear oil is going the other way too, and Fing my tranny?
Will there be any significant ill effects from running the transfer with ATF instead of oil for a few months? Any ill effects from the fluid level in the transfer being too high?

The way I see it there are three immediate options for dealing with this.
1 - tap the fill plug, install a breather and hope the issue is a vacuum building in the case and sucking ATF back through the seal
2 - keep the AT topped off and drain the excess out of the transfer (assuming there isn't fluid going the other way)
3 - flush the AT and transfer and run them both with ATF, draining excess in transfer as needed
4 - as above, but rig up a fluid return to the AT from the fill plug of the transfer, similar to when the seal goes with the manuals, then maintain the fluid level based on the level in the tranny


In the long term:
Does the blown seal mean anything beyond the standard rebuild parts needed to rebuild the transfer? I assume it is the oil seal around tranny output shaft that has gone, correct? If I've been running with basically ATF, any non typical parts that will likely show excessive wear?
If I rebuild this case, I'll most likely be doing the McNamara gear at the same time, I've got a good case of the clunks.

 

[Lost]

tcase: gear oil
auto tranny: atf
why mix both, it will work, but at what cost

just rebuild,seals + gaskets. get new bearings while youre at it. mcnamara get is way too expensive.

im no expert,
and i did rebuild my tcase, and i dont have to think about 'what if'

 

[RockDoc]

It's my daily driver, and I need to keep driving it till I get the rebuild kit and have time to tackle it. If running ATF in both units will get me by in the meantime with a minimum of wear, so be it.

Or another option:

I have a spare A440F/split case in the garage that is slated for another truck, but I assuming swapping these out as a unit would be more work than rebuilding the case that is on it....

 

[rfj62]

Interested to see how you handle this, as I am having the same issue.

 

[Bryan062087]

As long as you are not getting gear oil into the transmission, I think you are ok by just watching fluid levels and filling/draining as necessary.

I wouldn't switch to using all atf in the t-case, just try to mantain the correct level of fluid which hopefully will be primarily gear oil.

I had a similar but much more severe problem like this in my 62. My t-case itself leaked quite a bit and the seal between the transmission and transfer was screwed up to the point where it was allowing the two fluids (gear oil and ATF) to mix in both the transmission and transfer case.

I could never fill my transfer case up very high with gear oil because it would then leak into my transmission causing overheating- a big problem because I was loosing a lot of fluid out of my t-case seals. I recently tore my t-case down to rebuild it and there was no o-ring preventing the ATF from migrating to the xfer case and the other way around, which was probably a big part of the problem.

Too my disbelief, all the bearings in my transfer case were still in great shape despite having been run with little lubrication for who knows how long. Since I bought a kit, I replaced them anyways. I put an o-ring in and a new t-case to tranny seal, and no longer have any issues with internal leaking.

Sad to admit, but the ATF leaking to the transfer case is a common problem with 62's. If you are just getting a small amount of ATF into the t-case, its not a big deal. Just keep it filled up as best you can, hopefully with as much gear oil as possible.

Some people have said you can run ATF in the transfer case, but if you are not having problems getting gear oil into the auto tranny and the tranny is not overheating, and ATF still looks fresh on dipstick, I would not do it.

The problem I had seems pretty rare, and was probably due to one of the truck's p.o.'s.

Also, I'm by no means an expert on this subject, just speaking from my own experience.

Edit: Just read the part about the vacuum in case, I would try to check the breather first probably before I did anything. If thats the problem, you would be lucky.

 

[Granite Grinder]

I've been running straight ATF in my T-Case for a couple of months, this too is my daily driver, no ill effects. I had my doubts about this, but at a CC meeting smarter cruiserheads than me said no problem, in fact desirable if your running an auto. If you've got a 5 speed, keep it all gear oil. I have gear oil mixing with my ATF in the HJ. Trannies not liking it. Rebuilding the t-case is obviously the solution, but not a couple of hour job, especially if you don't have a press. I spent the afternoon just in the parts cleaner tank alone, and still didn't get everything as clean as I would like.
GG

 

[RockDoc]

Well it is too cold and snowy today to do anything about it, but when it warms up, I think I'll angle down the back end of the drivetrain and see if I can't get the breather cleared out.

 

[Lost]

i rebuilt my tcase in december, under my truck, outside in the cold with no experience and a printout of the fsm transfer chapter. one full week with a 40hr work week in there. changed all the bearings except rear output shaft.

i let the truck sit over a month before sucking it up
i didnt have a press, (it would of help)
if you can rebuild knuckles, you shouldnt have a hard time rebuilding tcase



would atf in the tcase, in the long run cause failure?
short term i wouldnt worry about it

 

[Cruiserdrew]

It's most likely just the seal between the two gear boxes. The seal actually seals not on the shaft, but on the shoulder of the input gear. If the splines are worn, it can even leak down the splines.

So, I would tear down the split case, leaving the front half of the transfer on the transmission. Then replace the seal, the McNamara input gear and you're done. You could do all of that in a day. Rebuilding the case would be a bigger job and would require a press for the output shaft bearings.

Good luck.

 

[RockDoc]

i rebuilt my tcase in december, under my truck, outside in the cold with no experience and a printout of the fsm transfer chapter. one full week with a 40hr work week in there. changed all the bearings except rear output shaft.

i let the truck sit over a month before sucking it up
i didnt have a press, (it would of help)
if you can rebuild knuckles, you shouldnt have a hard time rebuilding tcase



would atf in the tcase, in the long run cause failure?
short term i wouldnt worry about it

In the middle of december, damn, that's serious. I think the only serious work I've done outdoors in the winter on mine was swapping out a broken leaf while wheeling. Even at that, it was a beautiful day.

It's most likely just the seal between the two gear boxes. The seal actually seals not on the shaft, but on the shoulder of the input gear. If the splines are worn, it can even leak down the splines.

So, I would tear down the split case, leaving the front half of the transfer on the transmission. Then replace the seal, the McNamara input gear and you're done. You could do all of that in a day. Rebuilding the case would be a bigger job and would require a press for the output shaft bearings.

Good luck.

Well the output bearings feel tight, so I'm not worried about them. I've sent an e-mail off to McNamara, hopefully I hear back soon. If your description of the sealing method is correct, then I'm suspecting it's leaking in along the splines, cause I have the clunk something awful. I'll have to take a look in the FSM to see what the bare minimum of gaskets needed is, then drop Kurt a line and see if I can get a kit without bearings.

Thanks guys.

 

[Cruiserdrew]

You can order the stuff from Toyota, at least in the USA. You'll need the main case gasket, the output gasket(under the bearing retainer), the output rear seal, the idler shaft o-rings and the main seal in question. I'd goop some permatex on the splines too.

What's the long term plan? Manual tranny? Extreme tranny from Rodney?

 

[RockDoc]

Long term plan is to likely swap the tranny into the 2FE truck that's in the works. I have a second complete drivetrain, so which ever tranny is in better shape will end up in the 2FE truck. This one has the Extreme VB in it and fewer miles, but it's easy enough to swap over the VB if need be.

Oneway or another I'm going to have 2 rigs, and if this truck doesn't get the axe soon, it'll be a winter/wheeling beater.

 

[Bryan062087]

It's most likely just the seal between the two gear boxes. The seal actually seals not on the shaft, but on the shoulder of the input gear. If the splines are worn, it can even leak down the splines.

So, I would tear down the split case, leaving the front half of the transfer on the transmission. Then replace the seal, the McNamara input gear and you're done. You could do all of that in a day. Rebuilding the case would be a bigger job and would require a press for the output shaft bearings.

Good luck.

I agree with this, just doing that seal will not be too hard. (Note which way the old seal was oriented). Make sure you replace the o-ring too. But if you are going to tear everything a part in a few months, I'd wait.

 

[RockDoc]

I heard back from McNamara tonight. The gear goes for $300 US plus postage currently. A touch of sticker shock (well not too much, I was expecting north of $200) but I do need it....

 

[rfj62]

t's most likely just the seal between the two gear boxes. The seal actually seals not on the shaft, but on the shoulder of the input gear. If the splines are worn, it can even leak down the splines.

Are you guys saying that even if the seal is new it may still leak because the splines are worn?

I heard back from McNamara tonight. The gear goes for $300 US plus postage currently.

Ouch!

 

[RockDoc]

So I should have a McNamara gear on the way in the next few days, just need to hit up the back to do a wire transfer....

On the "rebuild" of the case, looking for a little experience on bearing condition.

The case on the truck has ~180 000 miles on it (assuming it's never been rebuilt). I can feel rotational slop from the rear output (a touch of "easy" slop, then some "stiffer" slop that I think is the input gear moving in the worn output splines) but can feel no side-to-side or up and down slop on either the rear or front outputs. Does this suggest that the bearings are still good? No noise from the t-case driving in 2 or 4wd, and there is no "roughness" feel when turning by hand. I think I can get away with gaskets and reuse the bearings.

In contrast, the rear output on the spare t-case I have has noticable side-to-side slop, and feels a touch "rough" when turned by hand, so I'm pretty sure it will need bearings if I end up using it on another truck. The "easy" rotational slop is about the same as the case on the truck, but it doesn't have the "stiffer" slop (good output shaft I hope, former owner never noticed any clunk...) So I think I have a feel for what is good and what is bad. Sound about right?

Between the FSM and Andrew's suggestions, this is what I came up with for a parts list. Anything I'm missing or I don't need?
-Main case gasket
-rear output bearing retainer gasket
-the oil seal for the input gear/ output shaft
-2 o-rings for the idler shaft
-rear output seal (is this needed if it isn't leaking?)
-#2 case cover gasket (access to the tranny output shaft locknut, or can I remove the rear half of the case with this intact and loosen the locknut against the parking pall?)
-PTO cover gasket (I think I can get away without this, correct?)
-rear companion flange locknut (needed or reuse?)
-tranny output shaft locknut (needed or reuse?)

Thanks for any direction you can offer.

Curtis.

 

[Cruiserdrew]

You do need new stake nuts. There are 3 of them, a 36mm on the end of the input shaft and one on each output. If you arn't rebuilding, you probably don'e need to replace the front output nut unless you're replacing that seal.

I'd take a hard look at the idler shaft and make sure it isn't badly worn.

 

[RockDoc]

You do need new stake nuts. There are 3 of them, a 36mm on the end of the input shaft and one on each output. If you arn't rebuilding, you probably don'e need to replace the front output nut unless you're replacing that seal.

I'd take a hard look at the idler shaft and make sure it isn't badly worn.

Stake nuts are the lock nuts? or a separate part? The FSM show lock nuts in the exploded diagram, and instructs to "stake" them. I'm assuming they're in fact the same thing, right? (sorry, never actually dealt with something that has a stake nut before)

On the idler shaft, are the commonly worn to where they should be replaced when there isn't any outward sign of t-case wear?

Maybe I should just get a full rebuild kit, I'll need everything for the other t-case anyway.....

 

[BG_TX]

Rockdoc, is the leak a 2 way street... meaning do you have gear oil in the trans and ATF in the transfer?

Just curious if/when this happens to me if I will be able to identify it by checking the ATF and seeing discoloration.

 

[RockDoc]

So far I would say no. My tranny level is dropping and the transfer was WAY overfilled. No contamination apparent on the dipstick. If I'm gonna do much driving before I get it fixed, I'll drop whatever is left in the transfer and fill it with ATF instead. ATF is the t-case isn't great, but gear oil in the tranny will kill it from what I gather.