what could make my 727 overheat bad enough to purge fluid out of the front seal after 30-45min of cruising?
i have a deep summit aluminum pan, and the biggest aftermarket trans cooler i can fit, im assuming its overheating it only leaks after driving and its a SERIOUS leak.
Posted By: RapidRobert
Re: 727 Overheats! - 04/29/11 01:28 PM
Hi Randy, not from overheating but from front pump seal needs R&R
Posted By: moparts
Re: 727 Overheats! - 04/29/11 01:44 PM
Over heating ?
Coming out the vent right above the seal?
The one time I overheated a trans it was coming out the filler tube also.
You sure that the trans was not just over full and fluid was expanding and coming out the vent
Posted By: JohnRR
Re: 727 Overheats! - 04/29/11 02:43 PM
A slipping trans will cause the fluid to overheat .
Posted By: coronet1966d
Re: 727 Overheats! - 04/29/11 02:46 PM
its not slipping, it not shooting out of the dipstick either. i have a cheetah reverse manual VB and a mancinis 3200 stall converter
Posted By: coronet1966d
Re: 727 Overheats! - 04/29/11 03:10 PM
its not overfilled either, this wasnt a small amount of fluid that came out. i could follow a trail a couple miles of fluid that dumped out. i lost 6 quarts total. the trans cooler is new, radiator is new and the trans lines are stainless steel pre bent and also new
Posted By: coronet1966d
Re: 727 Overheats! - 04/29/11 03:57 PM
like 99% of people on here i dont have a trans temp gauge
Posted By: Prodart440
Re: 727 Overheats! - 04/29/11 03:58 PM
Just because the radiator is new does not mean the cooler in it isn't plugged. I would check cooler flow.
Posted By: kilroy
Re: 727 Overheats! - 04/29/11 04:07 PM
These guys are giving you sound advise. It probably has to be one of the above. Step back and start trouble shooting. take lines loose blow air through cooler see if plugged. (note: cover end of line with rag so fluid does not spray everywhere.) Blow air through radiator cooler, blow air through cooler lines, drive again. If its not cured sorry bub, but the seal is shoot or their is an plugged internal passage. Sometimes new stuff goes bad or gets damaged even with the best care. Unless its really simple thing you are just missing there is not a magic bullet. Trouble shoot and get back to us!
Posted By: 68dodge
Re: 727 Overheats! - 04/29/11 04:47 PM
One thing I would do, is not run the trans fluid into the radiator cooler. I would only use the external transmission cooler.
Coronet1966d
I will shed some light on this, It has happened to me several times. I asked the question here and got the same responses.
I started trouble shooting with fluid levels, too low? no difference! then to a trans temp gauge? no difference! back to fluid level, to High? no difference!. Then slipping converter making too much heat? change gears! NO DIFFERENCE. it still did it.
more frustrating? there is nothing worse than puking trans fluid through the bellhousing vent in to windage of the converter to spray out every different direction under the car and start to burn onto the exhaust.
I finally spoke with a trans guy and explained to me that with a Cheetah Reverse Valve body somehow it spins the drum over what would be considered normal and foams the fluid until it pukes out.
He suggested that I go out and run the car like an old lady for an hour cruise and see if it happens. then on a different day drive the car hard shifting and like you want to drive it and see if it happens.
It did it as he said it would.
grandma drive, no trouble!.
grandson drive, puke and smoke!
I am no tranny guy so I dont know the technicals and argue with some "Mopar Experts" about how that is not possible. but I did the experiment and it proved it to me.
The solution is to block the vent in the bellhousing and install one in the tailshaft or main housing. the dragrace only forum is the place to ask about the moving of the vent because alot of them experience this trans problem.
please keep me posted if you do this test so I know I am not nuts. Henry
Ok, I can't debate what the internals are like I said (I plead ignorance to the reason it happens) I would love to hear why it happens to clear up what I was told. In laymans terms some one explain please. Any way coronet1966d the vent is the resolution.
Posted By: fox
Re: 727 Overheats! - 04/30/11 12:47 AM
Make sure the lower cooler line is the feed. If you run it thru the cooler top down it may not cool correctly.Do you have acsee to an infared heat gun? You could use it to check the temps.
Posted By: coronet1966d
Re: 727 Overheats! - 04/30/11 02:24 AM
well its cooked! i think its the pump or the planetary gears making a ton of noise
Posted By: BRONZEBEE
Re: 727 Overheats! - 04/30/11 04:19 AM
If your running road gears 2.76 3.23,with a 3200 stall might give you a problem.I think it will overheat the fluid in the converter,because the stall is to high for the gear ratio.Example 55 mph 2200 rpm,3200 stall.Your stall speed should be below your crusing rpm.
Well something in the story is missing. You said the tranny was leaking bad after cruising. If you read my reply then you know the valve body causes this problem (somehow). Now you say that it sounds like it is severely broken, that doesn't happen from overheating. Did you romp on it in first and let off hit it again, if your valve body doesn't have low band apply then that is what probably broke the internals and be happy that it didn't come apart entirely :-(
Posted By: 451Mopar
Re: 727 Overheats! - 05/01/11 07:41 AM
I had a torque converter with a crack in the hub where it goes into the pump and it leaked pretty bad, but that was a 904 transmission?
I like the vent relocation to the rear of the transmission too.