Pressurized transmission???

[0mineralgrey3]

I've done plenty of fluid changes on the manuals in my cobras. I have 3800 miles on my car and it's been getting harder to get in 3rd and it's really "notchy" for lack of a better term driving around now. I did change the fluid once before and didn't pay any mind to it. I just put it on the lift....and when I opened the drain plug ....wwwooooshhhhhhh. Air rushed in and fluid drains really slowly out of it. I cracked the top fill plug and of course it drains normally. What could cause this to pressurize like this. I'm pretty sure there is a vent to prevent such things. Where is the vent located. I can't remember where when I had it out to do the clutch. Could this cause some of the hard shifting issues.

 

[VFORCEJOHN]

perhaps the vent (if there) is a 1 way out to allow expansion of fluids, but not bring air back in? gear oil and trans fluid like any oil, will expand when hot, this can cause air to escape. when it does, it's not allowed back in.

 

[carguy19]

I've done plenty of fluid changes on the manuals in my cobras. I have 3800 miles on my car and it's been getting harder to get in 3rd and it's really "notchy" for lack of a better term driving around now. I did change the fluid once before and didn't pay any mind to it. I just put it on the lift....and when I opened the drain plug ....wwwooooshhhhhhh. Air rushed in and fluid drains really slowly out of it. I cracked the top fill plug and of course it drains normally. What could cause this to pressurize like this. I'm pretty sure there is a vent to prevent such things. Where is the vent located. I can't remember where when I had it out to do the clutch. Could this cause some of the hard shifting issues.

Anytime you drain a transmission you are supposed to take out the fill plug first (Or the dipstick on an auto).

The fluid isnt going to flow like water. Its much thicker. It needs the flow of air to push the fluid out of the drain. The air actually replaces the fluid in the case, then the fluid replaces the air when you refill out of the fill plug.

I may be mistaken, but I dont think the 6060 trans in our car or the T56s are vented. If they are the would definitely have a check valve in them like the previous poster said because fluid would seep out if it didnt have a valve.

 

[Snoopy49]

Maybe this will help.

View attachment 2013 GT500 Transmission Drainng and Filling.PDF

 

[2011 gtcs]

Since we're on the subject of transmission drain and fills what do you do if you have a track pack car and want to switch to AMSOIL? You can't drain all the old fluid out without removing the cooler. Has anyone with a track pack actually changed there transmission fluid yet?

 

[biminiLX]

Without some sort of pump or suction point in the TP loop, I think you're stuck with a partial fill.
I did feel a noticeable improvement with the switch to Amsoil.
-J

 

[mavisky]

No cooler here, but the car does feel better after switching to Mobil 1 ATF per Justin at VMP's recommendation.

 

[5.8 Venom]

^ 2nd this. I swapped to Mobil 1. For lack of a better description shifts with the stock fluid felt thin and rough. Mobil-1 feels thicker and shifts are firmer more solid. I dont have trackpack, so I just swapped it and 1500 miles later swapped it again. OCD $80 mod instead of $40.

 

[Snoopy49]

View attachment Transmission Fluid Cooler Backflushing and Cleaning.pdf

 

[tomshep]

I'm no expert, but this tranny has to have a way to equalize pressure due to heat (expansion) and cooling (contraction). Otherwise, it would get hot and push out a gasket or seal somewhere. Same as your motor or rear end, it needs to breathe. Some trannys have a vent similar to our diffs. Others, it is just a small hole in a cover plate to help equalize pressure. I would think it has to be somewhere.

Tom

 

[Snoopy49]

I looked through the 2014 Service Manual and the only mention of a transmission vent was in the trouble shooting section under transmission leaks. I wasn't able to find any other references to a vent. If it is in the manual, it's pretty hard to find.

Here is a picture of a Tremec TR6060 transmission that shows the vent location. It would be nice if someone could confirm the location on a GT500 transmission.

 

[Tob]

That's not the exact location, but close. When I get home I'll post up some photos of a '13/'14 TR6060 on a stand, out of the vehicle.

 

[carguy19]

That's not the exact location, but close. When I get home I'll post up some photos of a '13/'14 TR6060 on a stand, out of the vehicle.

The one above looks like it vents the bell housing/Clutch assembly, not the trans. Doesn't it?

 

[VNMOUS1]

No cooler here, but the car does feel better after switching to Mobil 1 ATF per Justin at VMP's recommendation.

This. I switched to it in '08 and it's like night and day.

 

[Snoopy49]

The one above looks like it vents the bell housing/Clutch assembly, not the trans. Doesn't it?

From some of the pictures I looked at, it looks like there is a passage way cast into the bell housing that goes into the transmission. Maybe someone with first hand knowledge can confirm?

 

[0mineralgrey3]

I just found it strange that the car had been sitting for days. I cracked the drain and i've never heard it sound like that. Was almost like opening a new 2 liter of coke.

 

[Norton]

Without some sort of pump or suction point in the TP loop, I think you're stuck with a partial fill.
I did feel a noticeable improvement with the switch to Amsoil.

+1.

 

[Tob]

...this tranny has to have a way to equalize pressure due to heat (expansion) and cooling (contraction). Otherwise, it would get hot and push out a gasket or seal somewhere. Same as your motor or rear end, it needs to breathe.

You hit it pretty well Tom.
I put some photos together to depict a few different vent configurations that Ford has used on their specified version of the TR6060.


From 2007-2012 Ford extended the rattle cap vent up and forward of the shifter rod cover plate...

Looks like Ford felt they could save a little money by relocating the rattle cap vent directly atop the cover plate for years 2013-2014.

From a technical standpoint, eliminating the vent extension wasn't the best idea. Note that the 2012 Boss 302S retained the early TR6060 vent extension when used behind the Coyote motor...

And when Ford abandoned the extension on the TR6060 when used on the '13/'14 GT500, Ford Racing specified for the '13 Boss 302S that Watson extend the line similar to what Ford used to do.

 

[Snoopy49]

Tob,
Thanks for posting the pictures and taking the time to explain them. It doesn't get any better than that.

 

[Tob]