HELP transmission mystery question

[spedigo]

hoping somebody out there can help me figure out how this is happening.

I’ve got a 350 transmission. My truck has been sitting in the same place for the past two weeks. Absolutely nothing has moved on the truck. Batteries been disconnected and intake Manifold has been off, so it’s been sitting dead still for at least two weeks.

I noticed yesterday that it has puked out a bunch of transmission fluid and it looks like it’s come out the tail housing.

How did that happen? Where did the pressure come from to push it out?

Replaced the tail housing seal several months ago and haven’t seen any problems with it prior to parking it several weeks ago.

So, no leak when parked. Fluid level was at the right level (when hot) when parked. i only started to see the leak in the last couple of days after sitting still for several weeks.

 

[PrairieDrifter]

hoping somebody out there can help me figure out how this is happening.

I’ve got a 350 transmission. My truck has been sitting in the same place for the past two weeks. Absolutely nothing has moved on the truck. Batteries been disconnected and intake Manifold has been off, so it’s been sitting dead still for at least two weeks.

I noticed yesterday that it has puked out a bunch of transmission fluid and it looks like it’s come out the tail housing.

How did that happen? Where did the pressure come from to push it out?

Replaced the tail housing seal several months ago and haven’t seen any problems with it prior to parking it several weeks ago.

So, no leak when parked. Fluid level was at the right level (when hot) when parked. i only started to see the leak in the last couple of days after sitting still for several weeks.

Transmission fluid does that. Im sure it almost emptied the torque converter, then proceeded to push it out anywhere it could. For some reason it must be expanding somehow, does it during temp fluctuations.

Never leave a trans with fluid sitting around during temperature fluctuations. Ask me how I know lol. You're good to go. Top it off and run it, check it again and check for leaks. I'm sure itll be fine.

 

[AuroraGirl]

hoping somebody out there can help me figure out how this is happening.

I’ve got a 350 transmission. My truck has been sitting in the same place for the past two weeks. Absolutely nothing has moved on the truck. Batteries been disconnected and intake Manifold has been off, so it’s been sitting dead still for at least two weeks.

I noticed yesterday that it has puked out a bunch of transmission fluid and it looks like it’s come out the tail housing.

How did that happen? Where did the pressure come from to push it out?

Replaced the tail housing seal several months ago and haven’t seen any problems with it prior to parking it several weeks ago.

So, no leak when parked. Fluid level was at the right level (when hot) when parked. i only started to see the leak in the last couple of days after sitting still for several weeks.

the only thing I could think is the modulator but its weird for it to just start like that...

 

[Dryriver1]

Hello @spedigo I hope all is well.

I would like to add that just like other equipment that has any type of rubber seals, O-rings, even metal to metal, like @PrairieDrifter mentioned "does it during temp fluctuations." at a stand still and especially with the cold front that just went through east Texas everything shrinks. as @PrairieDrifter mentioned, I highly agree "Top it off and run it, check it again and check for leaks. I'm sure itll be fine."

@AuroraGirl mentioned "the only thing I could think is the modulator" which is sealed by an O-ring too.

Once everything is nice and warm and back to working daily or every other day it will be good to go.

Be well and stay safe out there. Best wishes to you and all of your loved ones always!

Dryriver1

 

[RanchWelder]

Tail housing bushing and a worn seal sounds possible.
Easy fix.

Check the slip yoke for seal groove wear, before you relocate the new seal.
If it has a groove, change the yoke.

If you have a center drive shaft carrier bearing, change it and all the u-joints too.
Here in ranch country, u-joints only last 2-3 years, max.

Carrier bearings can go at any time.

 

[fast 99]

1/2 the fluid in the torque convertor will slowly drain into pan during extended periods of inactivity. The level will get above the output shaft and if the rear seal is weak may leak. Replace the seal, all will be good.

 

[trucktony]

1/2 the fluid in the torque convertor will slowly drain into pan during extended periods of inactivity. The level will get above the output shaft and if the rear seal is weak may leak. Replace the seal, all will be good.

exactly that
the level is even coming above the oilfiller tube grommet(top hat)
What I had was after a forthnight of sitting a serious amount of atf was laying on the floor because we installed the oilfiller tube not correct in the trans hole
When it's under tension on the grommet because it's to tight on the bellhousing bolt it leaks thru the grommet when the level rises because of converter drainage

Other thing that happend
When I had changed the yoke for an other one there seemed to be a pin hole right in the middle of the yoke's back (some seem to have that)(vent hole??)
And again when the oil level raised up by converter drainage(after 2 weeks) it started leaking (was a pain to find)(very small hole on an odd place)