Installing 727

[dwbiggs]

I have R&R'd my 727 a couple of times in the past and it always ended up leaking inn the front...not much...but there was always a drip or two under the car if it sat for a couple of days.  I don't know if it was something I did while installing it or something that the trans guy did.  I am about to install the tranny again and would like to know if there is anything I need to do beforehand to possibly keep it from leaking.  Is there something with the seal I need to prep before installation or something?

[JS23U0B]

It kinda sounds like you in the past have damaged the front seal when you put the converter in. IMO

[dwbiggs]

I have always put some oil on the converter and slid gently into the tranny turning it until it seated...is that the wrong way to do it?  What is the correct procedure?

[Chryco Psycho]

I always thought after sitting for a few days the converter would start to drain & overfill the trans causing the leak

[tactransman]

If it leaks sitting,then it is probably the pump "O" ring or maybe porosity in the case.

[dwbiggs]

Isn't the front seal supposed to prevent that? 

[tactransman]

Nope,the front seal seals against the converter hub. The pump "O" ring seals the OUTER pump body surface to the case. If the pump hole in the case has any imperfections to deep for the "O" ring to seal,it will leak when it sits and the fluid level raises.

[dwbiggs]

Leak from where...mine leaked from the front.

[tactransman]

Let me take some pictures later and I will post them to help you understand.

[RD]

If it leaks sitting,then it is probably the pump "O" ring or maybe porosity in the case.

i agree, but it may also be your pump bolts. not saying you did, but sometimes those little washers that come in the overhaul kits do not find their way in between the bolt and the pump housing. 

[solarguy]

I always thought after sitting for a few days the converter would start to drain & overfill the trans causing the leak

 , then fluid leaks from selector shaft seal or dipstick tube O ring. 

[tactransman]

This the front pump. The front seal is in the middle of the pump,seals against the converter hub. There is also a big rubber round "O" ring that seals the pump body to the case hole when it is installed in the case.

 See the groove around the outside edge of this pump? That is where the seals is installed.

[dwbiggs]

Mine always leaked from the front seal...down the bellhousing.

Got the tranny back and the guy said that there was a check ball missing in the piece that has the outer splines on it guess that is the pic you posted.  He also said that the piece had a hairline crack in it.

BTW...tactransman, the tranny is in and it seems to work good...have all gears and the MVB has no issues.  One thing I noticed though is that there is a slight pause going from 2-3.  Is this normal? 1-2 is immediate and chirps the tires even at fairly low speeds.  Haven't tried hard acceleration yet.

[tactransman]

Do you mean a pause when the shifter is pushed and the actual shift does not occur,or a pause while that actual shift is occurring?

[dwbiggs]

It does not shift immediately when I shift to "D"...this was at low speed if that makes a difference.
Haven't tried at anything above 40 mph...just tested in my subdivision.  Plan on taking it out on the highway tonight.