TH-400 Auto Transmission
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Joined: Mar 2007
Posts: 79
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From: Burbank CA
TH-400 Auto Transmission
I have leak.
From the Transmission.
I had the car jacked up this afternoon and wiped the whole of the transmission down, checked the filter cover bolts - one was a bit loose (big surprise!) and another turns in its hole without binding tight.
Then I notice on the bottom of the from of the radial cover (I'm thinking this is the bell housing - correct?) at the front of the cast transmission just behind the engine block, the black metal part of the assembly, there is a perfectly round hole in the thin guage metal housing.
There were a few scrapes under old grime as well.
This seems to hint to me that there was at one point a cover or plug in there that has been pulled out when the car has gone over a bump.
Would I be correct in thinking this?
Is this hole meant to be there?
Just spent a while looking through the assembly manual and there's no mention of it.
Anyone got any ideas for a fix?
From the Transmission.
I had the car jacked up this afternoon and wiped the whole of the transmission down, checked the filter cover bolts - one was a bit loose (big surprise!) and another turns in its hole without binding tight.
Then I notice on the bottom of the from of the radial cover (I'm thinking this is the bell housing - correct?) at the front of the cast transmission just behind the engine block, the black metal part of the assembly, there is a perfectly round hole in the thin guage metal housing.
There were a few scrapes under old grime as well.
This seems to hint to me that there was at one point a cover or plug in there that has been pulled out when the car has gone over a bump.
Would I be correct in thinking this?
Is this hole meant to be there?
Just spent a while looking through the assembly manual and there's no mention of it.
Anyone got any ideas for a fix?
Last edited by pipervette; Apr 4, 2007 at 03:11 AM.
Melting Slicks
Joined: Jul 2005
Posts: 2,060
Likes: 46
From: winter haven florida
St. Jude Donor '12
the black thing is just a dust cover and the hole is there as a drain for water ect. it is supposed to be open. nothing to worry about. now all you have to do is find your leak. you might try getting some foamy engine bright and clean the trans really good, then run it for a short time and see if you can trace the leak down. sounds like you might have a pan gasket leaking. i would look for the leak around the loose bolt first.
Instructor
Joined: Dec 2004
Posts: 236
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From: Clearwater Florida
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Your leak [or leaks] are from the oil pan gasket and/or the converter pump lip seal. The first one is best repaired by dropping the tranny oil pan and checking all of the bolt threads in the pan rail. Stripped threads can be repaired with heli-coils/inserts. Make sure the heli-coil does NOT stick out on the gasket side of the rail. If the rail is very thin where a thred is stripped, you could use a thru-bolt with a nut on top of the pan rail (not advised, but sometimes necessary). If the leak is out the inspection cover (and not coming from the front edge of the oil pan splitline), the charging pump lip seal is likely worn. You have to drop the tranny and pull the converter to change out that seal. If you go that far, you might as well do a rebuild on the tranny. Many folks wait until the leak is bad enough to justify replacement/repair.
