Scratching my head after transfer case fluid change...

[89Suburban]

Last weekend I replaced my transfer case fluid. Done this many times on many 4x4's I have owned over the years. This time it's got me baffled, or I am just getting old and senile?

I cracked both the plugs loose.Then removed the drain plug. The old oil came out fast. When I removed the fill plug MORE oil came out of THAT hole! That freaked me out. Why the hell is it doing that??? Shouldn't it be coming out the bottom hole??

So I put the drain plug back in and started to fill it back up using a hand pump and hose. The book calls for 2 quarts. I pumped all 2 quarts in and still nothing came out of the fill hole, BUT when I removed the fill hose it must have been snug enough to block the damned hole so fluid started gushing the **** out.

So I am laying there on my back all ****** up and panicking with this brand new fluid running out all over the place and thinking should I let it keep doing that? Can it really be that over full if it is calling for 2 qts?? I mean I swear by the time I had to react I lost at least a half quart. I just jammed fill plug back in and snugged them up. Shit's got me a bit nervous....

 

[wjburken]

Last weekend I replaced my transfer case fluid. Done this many times on many 4x4's I have owned over the years. This time it's got me baffled, or I am just getting old and senile?

I cracked both the plugs loose.Then removed the drain plug. The old oil came out fast. When I removed the fill plug MORE oil came out of THAT hole! That freaked me out. Why the hell is it doing that??? Shouldn't it be coming out the bottom hole??

So I put the drain plug back in and started to fill it back up using a hand pump and hose. The book calls for 2 quarts. I pumped all 2 quarts in and still nothing came out of the fill hole, BUT when I removed the fill hose it must have been snug enough to block the damned hole so fluid started gushing the **** out.

So I am laying there on my back all ****** up and panicking with this brand new fluid running out all over the place and thinking should I let it keep doing that? Can it really be that over full if it is calling for 2 qts?? I mean I swear by the time I had to react I lost at least a half quart. I just jammed fill plug back in and snugged them up. Shit's got me a bit nervous....

Is this the first time you changed the fluid on this vehicle?

How much fluid drained out before you started putting new stuff back in?

 

[Mechanic421]

If transfer case was initially over full seal between transmission and transfer case is leaking. Transmission is probably low.

 

[JonnyTahoe]

If transfer case was initially over full seal between transmission and transfer case is leaking. Transmission is probably low.

This is correct. Had this happen when I drained my T-case before removal. 2 quarts went in and 4 quarts drained out. Had filled with Delco Auto-Trak2 Fluid. It is blue in color so when Twice what I put in came out dark red I knew we had a problem.

 

[wjburken]

If transfer case was initially over full seal between transmission and transfer case is leaking. Transmission is probably low.

If I recall correctly, the spacer flange that goes between the transmission and the transfer case is dry, at least it was on my 2007 AWD, so if the transmission is leaking, that cavity would be full as well. Might crack the bolts loose between the transfer case the the transmission and see if fluid comes out there. I believe it is just a paper gasket that goes between the transfer case and the spacer flange.

 

[JonnyTahoe]

It's a internal Transmission Seal failure causing fluid under pressure to fill up the Transfer Case. No indication of this what so ever. No leaks of any kind. Tranny shop figured it occurred when Internal parts failed. Transfer Case ok found Needle bearings and small metal parts in Trans Pan.

 

[George B]

It's a internal Transmission Seal that fails causing fluid under pressure to fill up the Transfer Case.

How often does this happen?

 

[JonnyTahoe]

How often does this happen?

Hopefully never. Mine was the result of my Trans finally letting go at 295k.

 

[JonnyTahoe]

Last weekend I replaced my transfer case fluid. Done this many times on many 4x4's I have owned over the years. This time it's got me baffled, or I am just getting old and senile?

I cracked both the plugs loose.Then removed the drain plug. The old oil came out fast. When I removed the fill plug MORE oil came out of THAT hole! That freaked me out. Why the hell is it doing that??? Shouldn't it be coming out the bottom hole??

So I put the drain plug back in and started to fill it back up using a hand pump and hose. The book calls for 2 quarts. I pumped all 2 quarts in and still nothing came out of the fill hole, BUT when I removed the fill hose it must have been snug enough to block the damned hole so fluid started gushing the **** out.

So I am laying there on my back all ****** up and panicking with this brand new fluid running out all over the place and thinking should I let it keep doing that? Can it really be that over full if it is calling for 2 qts?? I mean I swear by the time I had to react I lost at least a half quart. I just jammed fill plug back in and snugged them up. Shit's got me a bit nervous....

A video of that Fluid change would of got you a million views on YouTube.

 

[Fless]

Curious about what fluid your TC takes, and if it's the same as tranny fluid.

 

[JonnyTahoe]

Curious about what fluid your TC takes, and if it's the same as tranny fluid.

 

[Fless]

To be clear, I'm wondering if the TC takes transmission fluid (red) or something like AutoTrakII (blue).

 

[JonnyTahoe]

To be clear, I'm wondering if the TC takes transmission fluid (red) or something like AutoTracII (blue).

.

 

[Fless]

I like this Fluid.View attachment 241484

I do, too, since my TC calls for that fluid, but it might not be the right type for the OP's TC.

 

[JonnyTahoe]

I do, too, since my TC calls for that fluid, but it might not be the right type for the OP's TC.

Your call.

 

[Mechanic421]

Each are different you really need to check the manual. Mine takes atf and I change it often. I really don’t like autotrac! If my case did call for it I would use it. But I would change it even more often. I am not a fan of autotrac! Some say you can use good synthetic atf I have not experienced so I can not say. There should be a tag on case for model of case .

 

[89Suburban]

Is this the first time you changed the fluid on this vehicle?

How much fluid drained out before you started putting new stuff back in?

Yes, first time since I owned it anyway. I would say 1 1/2 came came out now that you mention it. It was beat and dark looking, sure it is way overdue. I don't think I have a trans leak into the Maybe it only holds 1 1/2 instead of 2 like the book says? Dunno.

 

[89Suburban]

.View attachment 241484

This is what I used and the book calls for. The Auto Trac II.

 

[JonnyTahoe]

Yes, first time since I owned it anyway. I would say 1 1/2 came came out now that you mention it. It was beat and dark looking, sure it is way overdue. I don't think I have a trans leak into the Maybe it only holds 1 1/2 instead of 2 like the book says? Dunno.

whatever you put in it fill it till it starts running out the filler hole. They will hold a gallon but that's not recommended. (only when your tranny seal fails)

 

[JonnyTahoe]

This is what I used and the book calls for. The Auto Trac II.

Book recommends it because it's the OEM fluid.