weird TH400 leak - Pontiac GTO Forum
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post #1 of 10 (permalink) Old 05-27-2019, 05:46 PM Thread Starter
 
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weird TH400 leak

ok, never seen this before so I want to get some opinions.....working on my sons 69 GTO, 400 with a th400 trans......we replaced the carb today, had a throttle issue...it got stuck on WOT a few times very breifly....anyway....the transmission started leaking like crazy, easily a quart or so, trans was in park the entire time, never put it in gear....the leak is between the torque converter and the trans itself, like the front pump shaft maybe....my question is what happened? did the brief high WOT rpm mess up the torque converter? or the front seal? front pump maybe? any ideas on this one?

thanks,

Mike
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post #2 of 10 (permalink) Old 05-29-2019, 03:27 PM
 
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I'm probably not much help here, but I'm trying to think about this logically. I, and probably many of us have had our motors at wot several times in the past, and me personally, I never experienced transmission leaking. A coincidence?? Not sure. The leaking like you describe can only come from a few places, to my knowledge. Front seal. A crack in the case. Front pump. I don't know about the internals of the torque converter. I chased a serious leak for the longest time before discovering the dip stick tube wasn't seated properly in the main case. Could this have come loose or out?? Sorry, wish I was more experienced with this stuff, but I'm not, Nicholas.
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post #3 of 10 (permalink) Old 05-29-2019, 05:28 PM
 
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Could it have been overfilled, warm it up and recheck the level
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post #4 of 10 (permalink) Old 05-29-2019, 07:57 PM Thread Starter
 
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thanks for the replies...leak is definitely coming from the front of the transmission...talked to a few local guts who are good with cars, their guess is the front pump over pressurized and puked out the front seal....will be dropping the transmission this weekend and see
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post #5 of 10 (permalink) Old 05-30-2019, 05:14 AM
 
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Originally Posted by MJS69 View Post
thanks for the replies...leak is definitely coming from the front of the transmission...talked to a few local guts who are good with cars, their guess is the front pump over pressurized and puked out the front seal....will be dropping the transmission this weekend and see
Please keep us posted on what you find. Thanks, Nicholas.
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post #6 of 10 (permalink) Old 05-30-2019, 07:45 PM Thread Starter
 
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absolutely...hoping it's just the seal, quick fix
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post #7 of 10 (permalink) Old 06-10-2019, 11:28 AM Thread Starter
 
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looks like the bushing walked forward...
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post #8 of 10 (permalink) Old 06-10-2019, 03:30 PM
 
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Well, at least you found the problem. What would cause that to happen??
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post #9 of 10 (permalink) Old 06-11-2019, 10:50 AM Thread Starter
 
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sudden high RPM when the throttle stuck I think
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post #10 of 10 (permalink) Old 06-25-2019, 10:36 AM Thread Starter
 
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new bushing and seal, and all is well again
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  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions.

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