727 Torqueflite rear vent install question.

[malex]

Guys: Looking for advise on where to drill to vent the case on the rear of a 727 Torqueflite. What type of vent is best, hole size, 1/8 or 1/4 pipe thread? Ebay sells the small plastic vents and any experience and advise on those would be good too.
I've added a few pictures of where I'm at.

I have taped and plugged the front pump vent already.

This is where I want to put the vent. Have any of you guys installed the vent in this location? It's open just behind the bolt boss which would allow venting from the rear housing.

 

[oldbee]

I need a re-edification, what’s the advantage? I remember hearing/reading of this yrs ago. I would think 1/4” NPT would be better?

 

[Tex013]

Done it on a few transmissions .
I used a brass 1/8"NPT right angle fitting , ran a hose up to a small catch can on firewall

Tex

 

[malex]

I need a re-edification, what’s the advantage? I remember hearing/reading of this yrs ago. I would think 1/4” NPT would be better?

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I'm told that it's recommended for transbrake and low ET cars to relocate the vent to eliminate fluid loss out of the stock vent. This transmission is one that I'm doing for a future project and decided to relocate it while I was into it. I also put a good sprag in it, red clutches, bands, billet servo and the likes.

 

[malex]

Done it on a few transmissions .
I used a brass 1/8"NPT right angle fitting , ran a hose up to a small catch can on firewall

Tex

View attachment 571642

Done it on a few transmissions .
I used a brass 1/8"NPT right angle fitting , ran a hose up to a small catch can on firewall

Tex

View attachment 571642

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This is exactly what I was needing Tex. Thanks!!

 

[dvw]

I ran 1/8" pipe tap. Then a push lock adapter with 1/4" nylon line to the back bumper in a 3oz catch can. That way if it spits it won't be under the tires. never has filled the can in 6 years. tapped the hole in the spot you have indicated. Tapped the pump 1/4"pipe and plugged the factory vent.
Doug

 

[mopar 3 B]

First I have ever seen this. Only disadvantage would be is how much fluid leaves the trans pan on acceleration? Could fluid possibly block the passage and temporarily pressurize the front of the case?

 

[malex]

I ran 1/8" pipe tap. Then a push lock adapter with 1/4" nylon line to the back bumper in a 3oz catch can. That way if it spits it won't be under the tires. never has filled the can in 6 years. tapped the hole in the spot you have indicated. Tapped the pump 1/4"pipe and plugged the factory vent.
Doug

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I did the pump today with a 1/8th plug on the inside. The rear will also get a 1/8th fitting now and in that exact spot. A catch can at the rear bumper, that's a fair length of hose.
Thanks for the advise!

 

[malex]

First I have ever seen this. Only disadvantage would be is how much fluid leaves the trans pan on acceleration? Could fluid possibly block the passage and temporarily pressurize the front of the case?

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From what I understand there is little fluid splash in the rear and this specific spot is very shielded, and still open to venting.

 

[mopar 3 B]

So just drill and tap the hole and install a manual trans vent and forget it.

 

[malex]

So just drill and tap the hole and install a manual trans vent and forget it.

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Yes that's about it.
I like the idea of a hose to a raised catch can but I see these are sold on ebay.

 

[Wookie316]

No vent relocation on mine and no leaks. Cope doesn’t do it anymore on his builds. Told me why but I forget the reason.

 

[malex]

No vent relocation on mine and no leaks. Cope doesn’t do it anymore on his builds. Told me why but I forget the reason.

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Hi Wooks. Got that Mopar back together yer?
Same with me, never had any leaks neither. If you happen to remember why Cope no longer vents at the rear let me know.
One another note, my Plymouth transmission is pretty much done, just waiting on one last part. Mark told me that he vented my trany to the rear so I decided to rear vent this one too.

 

[Wookie316]

Just got back from Mexico. Honestly have not done a thing on Barney. Will get back at it soon though.

 

[LemonWedge]

My 727 has been leaking out the bellhousing vent for years. Only problem was I didn’t know that was the deal. I’ve dropped it twice to try to fix it thinking it was a leaky seal or something. First time just re-sealed and gaskets the pump housing, second time l ended up rebuilding the entire tranny, re-installed..... same damn leak. Frustrating thing is I had heard about this mod but just never put 2 & 2 together & realized the vent was what I was dealing with.
I’ve heard the stock vent location will often start puking fluid when a manual valve body pushing higher line pressures is in use (???).

 

[malex]

My 727 has been leaking out the bellhousing vent for years. Only problem was I didn’t know that was the deal. I’ve dropped it twice to try to fix it thinking it was a leaky seal or something. First time just re-sealed and gaskets the pump housing, second time l ended up rebuilding the entire tranny, re-installed..... same damn leak. Frustrating thing is I had heard about this mod but just never put 2 & 2 together & realized the vent was what I was dealing with.
I’ve heard the stock vent location will often start puking fluid when a manual valve body pushing higher line pressures is in use (???).

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I recently read that with valve body upgrades and increased pressure vents can leak. It was the same as what you experienced LW.

 

[dvw]

The rear vent needs to be in the right location. A few years ago I broke a tooth off my lightened up parking pawl, don't ask. Anyway it came though the tail shaft right behind the right upper housing bolt. Fluid covered the entire bottom of the car.
Doug

 

[malex]

View attachment 571760 The rear vent needs to be in the right location. A few years ago I broke a tooth off my lightened up parking pawl, don't ask. Anyway it came though the tail shaft right behind the right upper housing bolt. Fluid covered the entire bottom of the car.
Doug

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Tough break, literally, but talk about on a hunt to shed lbs. That shows that if that vent isn't placed properly it will take on a lot of oil. Any idea of how much oil goes gets up into that hose? Forward motion could help push along any oil that is getting up in.

 

[451Mopar]

Guys: Looking for advise on where to drill to vent the case on the rear of a 727 Torqueflite. What type of vent is best, hole size, 1/8 or 1/4 pipe thread? Ebay sells the small plastic vents and any experience and advise on those would be good too.
I've added a few pictures of where I'm at.

I have taped and plugged the front pump vent already.
View attachment 571613

This is where I want to put the vent. Have any of you guys installed the vent in this location? It's open just behind the bolt boss which would allow venting from the rear housing.
View attachment 571614

View attachment 571615

Yes, that is the right location. Also, I drilled a small hole in web part below the hole so any trans fluid can drain and not fill that area.
I have these fittings with nylon air brake tubing running up to the fill tube and zip tied. I haven't had any fluid come out the vent tube.



https://www.amazon.com/gp/product/B00B6J1X8M/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B00CLXGHQU/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

 

[malex]

Yes, that is the right location. Also, I drilled a small hole in web part below the hole so any trans fluid can drain and not fill that area.
I have these fittings with nylon air brake tubing running up to the fill tube and zip tied. I haven't had any fluid come out the vent tube.

View attachment 571787

https://www.amazon.com/gp/product/B00B6J1X8M/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B00CLXGHQU/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

I like that fitting and using synflex line. Thanks!