TH 400 w/ Coan Trans Break blows ATF out of vent
#1
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TH 400 w/ Coan Trans Break blows ATF out of vent
Anyone got an idea why ATF blows out the vent tube on top of my TH 400 on a pass? Ran it up on the break and through the gears on stands but no leaks or fluid from vent. Possitive about coming out of vent, put a temp bottle on it and captured 2 or 3 ounces each pass. Has TCI deep pan, run Pennzoil ATF at normal level on dip stick. Even tried to drop 1 quart ATF. Still came out of vent. Trans shifts fine.
Car does wheelies, runs low 9's. Blown 427 SBC 900 hp.
Too much pressure? Too much heat? Too much ATF? Need baffle in pan?
Dave
Car does wheelies, runs low 9's. Blown 427 SBC 900 hp.
Too much pressure? Too much heat? Too much ATF? Need baffle in pan?
Dave
#3
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RACING JUNKIE
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Location: austin texas
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THe center support bolt is leaking pressure in the case.
If it has been raced alot the case is sure to be wallered out where the center suport bolt goes. So it will pressureize the pan and vent
If it has been raced alot the case is sure to be wallered out where the center suport bolt goes. So it will pressureize the pan and vent
#4
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Originally Posted by hammertime
how hot is it getting ?
I do have a good B&M cooler mounted under the car with it's own fan.
Dave
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Originally Posted by kwkracing
THe center support bolt is leaking pressure in the case.
If it has been raced alot the case is sure to be wallered out where the center suport bolt goes. So it will pressureize the pan and vent
If it has been raced alot the case is sure to be wallered out where the center suport bolt goes. So it will pressureize the pan and vent
Only change we made to the set up is we upgraded with an additional torrington bearing (I think) between the direct and the intermmediate clutch, but didn't change the clutches. Wish I had now. 20/20 hindesite that might have eliminated one possibility.
I guess it's still possible that it's leaking internally however. Is there any way I can tell if the bolt is leaking, and is there a fix if it is?
Also is it possible that there is pressure coming from the valve body not sealing to the case, or some other common internal pressure leak? There is no gasket on either side of the Coan valve body, just metal to metal contact.
Dave
#6
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The only way to check the center support is a visual, th400s like to waller that hole out where it seals. It only takes a little and the case leaks. One other thing is to take a punch and swell out the end of the governor tubes so they fit snug in the case and valve body.
#7
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Originally Posted by kwkracing
The only way to check the center support is a visual, th400s like to waller that hole out where it seals. It only takes a little and the case leaks. One other thing is to take a punch and swell out the end of the governor tubes so they fit snug in the case and valve body.
Thanks again, Dave