Driveshaft leaking ATF

[ARigutto]

Hello everyone, my 2003 dodge ram 2500 4wd has ATF coming out of what I assume is a weep hole in the first hole of the driveshaft after the transfer case. The transfer case side of the damper that is on the driveshaft looks drive and I replaced the output shaft seal of the transfer case when I put it back in about 23,000 miles ago. So I don’t. Not believe it is leaking from there. I know the transfer case is a 273-D and I assume there must be a seal to keep ATF from entering the end of the driveshaft but I have not been able to find on on any parts diagrams.

Has anyone else run into any problems like this? I have found this seal kit https://transend.us/products/transmission-parts/transfer-case-parts-units/gasket-kits/tsk273d but I don’t know if a seal kit will fix it or is something has happened to the driveshaft. This truck is my daily driver and I don’t really have the ability for it to be down right now which is why I came here first looking for advice. I have checked the fluid levels on the transfer case and the transmission and both are still full. I have heard there is a possibility for the transmission fluid to leak through the output shaft seal of the transmission and into the transfer case. Is this true? Wouldn’t you also see it leaking here the two cases meet?

Any advice is much appreciated. Thank you for your time.

 

[Topzide]

How much end play is on the drive shaft? See from pics that there's a good bit of seal wipe on stub. With truck sitting, how much forward/backward movement? That could be causing seal wear and a leak. Also, when sitting overnight, how much fluid drips? A little bit of oil looks a lot worse than it is. Need to do the old cardboard diagnostic on it. How much over how much time. Glad to hear that you are like just about all of us on here with how we keep up on our trucks! Fix it before it becomes a bigger issue. I'm sure others may have some more insight. Keep us informed on the adventure.

 

[petersonj]

I have never had this problem, but I think this is what may be going on. I think ATF is passing internally through the slip yoke shaft and around a plug that is located inside of the end yoke. Some people clean around the plug and add RTV sealant. The fellow in the video went a step further and removed the tail shaft housing from the transfer case and replaced an o-ring that is supposedly the culprit. He was working on a Chevrolet.

The still photo (at 9:37 in the video) shows the O-ring in his hand with his finger pointing to where the O-ring should be installed.

Hope this helps.

- John

 

[Ozymandias]

The slip yoke is lubed by the ATF.
If it is leaking right through the slip yoke then there is a "hole" where it shouldn't be.

Seal is only the one you can see right away, the part you see is a dust boot with the little weep hole in it, I side is a lip seal that will leak after many years of heavy use.

But something is often overseen, there is also a bushing in the tail cone that actually guides the slip yoke, and most of the time this bushing is worn which leads to a leaking lip seal.
So, if the seal leaks, check the radial play of the slip too, if it is excessive, replace the bushing too.

 

[ARigutto]

How much end play is on the drive shaft? See from pics that there's a good bit of seal wipe on stub. With truck sitting, how much forward/backward movement? That could be causing seal wear and a leak. Also, when sitting overnight, how much fluid drips? A little bit of oil looks a lot worse than it is. Need to do the old cardboard diagnostic on it. How much over how much time. Glad to hear that you are like just about all of us on here with how we keep up on our trucks! Fix it before it becomes a bigger issue. I'm sure others may have some more insight. Keep us informed on the adventure.

Honestly I don’t think there is very end play or in and out play. I even put the parking brake on and put the transmission in neutral and all I was about to get was a little rotation from the slack in the chain. There might be a little side to side and up and down play which could be the bushing in the back of the case. Honestly it really isn’t much fluid. I have just noticed a drip area on the ground but it isn’t even wet when you look at it. I just see the oil residue building on the frame, exhaust, skid plate and rear axle and everything else in between. A leak is a leak and I don’t like leaks so I want to fix it properly.

I attached a few photos that might give you and idea of the amount of oil.

 

[ARigutto]

I have never had this problem, but I think this is what may be going on. I think ATF is passing internally through the slip yoke shaft and around a plug that is located inside of the end yoke. Some people clean around the plug and add RTV sealant. The fellow in the video went a step further and removed the tail shaft housing from the transfer case and replaced an o-ring that is supposedly the culprit. He was working on a Chevrolet.

The still photo (at 9:37 in the video) shows the O-ring in his hand with his finger pointing to where the O-ring should be installed.

Hope this helps.

- John

View attachment 136945

I have seen this leak on the Chevy transmissions and transfer cases and I knew there was a seal in there for the chevys. I know it isn’t supposed to be leaking but I don’t know if that end cap in the yoke is supposed to be sealed and that seal has failed or if there is a seal in front of the yoke.

 

[ARigutto]

The slip yoke is lubed by the ATF.
If it is leaking right through the slip yoke then there is a "hole" where it shouldn't be.

Seal is only the one you can see right away, the part you see is a dust boot with the little weep hole in it, I side is a lip seal that will leak after many years of heavy use.

But something is often overseen, there is also a bushing in the tail cone that actually guides the slip yoke, and most of the time this bushing is worn which leads to a leaking lip seal.
So, if the seal leaks, check the radial play of the slip too, if it is excessive, replace the bushing too.

I do not believe that seal is leaking because there is no oil in front of the metal dampener that is just before that yoke. To me it looks like the oil is coming out through the yoke itself. If the seal is bad then you think it would be oily and wet on the transfer case side right?

There is potential that bushing is work out of the driveshaft yoke is grooved and I will have to check that out.

 

[Ozymandias]

There is a press-in cap inside the slip yoke, seems that yours isn't tight anymore.
It's designed like a frost plug.

#ad


You can try to seal it up from the outside or replace the yoke.
There is no seal inside.

 

[Topzide]

@Ozymandias, Could you pull yoke and take cap out, clean and put some loctite on the cap to try and seal it up? I know this should seal and also lock the cap in place.
@ARigutto, You can set rear axle on jack stands with slope forward to keep fluid from running out of transfer. Did this on mine when I had to replace rear transfer seal. After looking at pictures again, it would appear that @Ozymandias may be on the right track with cap being loose. Good luck with repairs. I'm the same when I notice a leak! Want it fixed as soon as possible!

 

[Tuesdak]

After a couple seals on my 2003 NV5600 2WD they shop did as @Ozymandias is showing you: addressed the plug on the yoke. I believe mine just took some RTV to fix it.

Wouldn't hurt to evaluate the entire driveshaft and have it rebuilt if needed.

Regardless your pictures show the freeze plug on the yoke leaking.

 

[Ozymandias]

On can try with proper de-greasing and some RTV to seal it up.
Everything else would involve disassembly of the u-joint which is a risk to damage the yoke.

Pulling the driveshaft is no big deal, there is only very little residue ATF leaking from the tail cone, maybe half a shot glass or less.

 

[sag2]

The output shaft seal is completely dry and has nothing to do with the leak. Ozy is correct, it is the end of the yoke that is leaking.

 

[ARigutto]

Thank you to everyone who has responded. I will be pulling the driveshaft and inspecting that yoke and the transfer case.

To replace that yoke is there a reputable place to get a new one from? Does the driveshaft need to be rebalanced if just a new yoke is installed?

I replaced all the driveshaft u joints when I installed everything but I’ll get a new u joint to install just in case the old one doesn’t want to play nice. I will also replace the seal on the end of the transfer because it’ll probably start leaking once I touch it.

Does anyone have any recommendations on where to get a new transfer case actuator motor. The one that shifts from 2WD to 4WD. I disconnected the electrical from it while I was under because the harness looked oily and ATF was dripping out of which probably means that motor is toast or at least the seals. But since it has had ATF go through it I think it would just be best to replace it with new.

 

[Topzide]

Not sure why you need to replace the yoke? The cap pops out of the end, clean it up along with the cap, put the appropriate Loc - Tite on it to seal and hold it into place. Would replace at least that u-joint at the yoke. Only re-use one if repairs needed to get back to civilization! To many chances that could cause issues. Yes on the seal and maybe a bushing if any slop in the rear housing. Good luck on the repairs and let us know what you find.

 

[Killer223]

is this a crack?

 

[sag2]

If it was you would think it would be leaking oil. Hit it with a grinder or file and see if you can still see it. I would guess its a casting flaw.

 

[BigPapa]

is this a crack?

Looks like a rib in the casting to me.

 

[bcbender]

I believe its a shadow from another rib in front of the larger on. As for the cap, you should be able to pop it out, clean it and reinstall with some sealant without removing the U joint if I remember correctly but its been along time. Key is that its sealed to the yoke to prevent ATF from escaping along the output shaft splines.

 

[BarryG]

I think I have noticed the light thing as well when washing my truck. I don't wash it often enough to have been able to make rhyme or reason as to why or if there is a specific area I am washing that causes it or if I have just bumped the key fob in my pocket or something. Everything has worked fine so never worried about it. So far I am just chalking it up to it really enjoys a wash and is letting me know. Living on a dirt road the truck is dusty immediately when it is dry or muddy immediately when it is wet or slushy and muddy in the winter time all before I even park it in the driveway. I could spend $100k a year on washes and it wouldn't look any better beyond the 30 minute ride home from the car wash, though I do enjoy that 30 minutes of nice bright and clean only to have my happiness dashed every dang time.

 

[BigPapa]

I think I have noticed the light thing as well when washing my truck. I don't wash it often enough to have been able to make rhyme or reason as to why or if there is a specific area I am washing that causes it or if I have just bumped the key fob in my pocket or something. Everything has worked fine so never worried about it. So far I am just chalking it up to it really enjoys a wash and is letting me know. Living on a dirt road the truck is dusty immediately when it is dry or muddy immediately when it is wet or slushy and muddy in the winter time all before I even park it in the driveway. I could spend $100k a year on washes and it wouldn't look any better beyond the 30 minute ride home from the car wash, though I do enjoy that 30 minutes of nice bright and clean only to have my happiness dashed every dang time.

Post in the wrong thread, maybe?