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Cannot locate a leak

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Old Jun 25, 2017 | 07:52 PM
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Default Cannot locate a leak

7/2/2017 update: It was the wiring harness right above the pan on the passenger side. The clips were broken, which caused the leak.


What are some obvious areas or things to check on a 4L60E? I had it serviced last year due to clutch issues and slippage. Everything was supposedly fixed.

As soon as I got it home and it sat overnight, it leaked a few quarts of fluid. Tires are probably ruined right since they sat overnight in fluid. What do you think?

I replaced the dipstick grommet, wasn't the problem. Leaked again overnight. Replaced the dipstick tube entirely. Didn't leak for a few hours, went out the garage this morning and it leaked a few quarts again. Looks like the leak is near the dipstick tube, but that possibility has been eliminated. It's just hard to tell since the the floor might be slightly sloped towards the garage door.

I can't seem to clearly see where the leak originates from.

Last edited by allbaugh_04; Jul 2, 2017 at 07:42 PM.
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Old Jun 26, 2017 | 06:22 AM
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Which trans do you have, 60E, 80E, 400, 350 PG, something out of an Edsel, etc, lol.
Are you sure its leaking several qts? are you over filling it? it doesn't take a lot to look like a lot.
If several qts, almost has to be a hole in the pan.
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Old Jun 26, 2017 | 10:29 AM
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Put a piece of cardboard under it. Have you check the shift shaft seal? When a trans sets for a while the fluid will drain out of the TC and the fluid level in the pan will rise above the shift shaft seal.
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Old Jun 26, 2017 | 11:04 PM
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Originally Posted by forcd ind
Which trans do you have, 60E, 80E, 400, 350 PG, something out of an Edsel, etc, lol.
Are you sure its leaking several qts? are you over filling it? it doesn't take a lot to look like a lot.
If several qts, almost has to be a hole in the pan.
60E. No, I made absolutely sure I didn't overfill it. It's around 2-3 qts of fluid loss.

Originally Posted by bbond105
Put a piece of cardboard under it. Have you check the shift shaft seal? When a trans sets for a while the fluid will drain out of the TC and the fluid level in the pan will rise above the shift shaft seal.
Ok, I can buy one of those and try to replace the shift shaft seal. Would it lose 3 quarts of fluid though with this seal? That seems very high. I'm going to do the pan gasket as well.

I was under it tonight and it's definitely not the dipstick, looks like the pan seal to me, but it's really hard to get a good view of the trans underneath the car, as you all probably know.

Last edited by allbaugh_04; Jun 26, 2017 at 11:14 PM.
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Old Jun 27, 2017 | 12:03 AM
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Are you sure it isn't coming from the bell housing? I'm saying this because I have a similar but way minor leak, at first I thought it was the pan gasket or the shift lever seal, I replaced both to no avail. It was then when I realized it was coming from the bellhousing area. The leak on my 4l60e seems to be either torque converter or pump related, when it leaks the fluid travels to and around the pan gasket and shift lever area so it makes it look as if it is the pan. I blasted it with brake cleaner and put some bits of napkin between the bellhousing and tranny where there is a groove so the oil would soak it. and wouldn't go anywhere else that's how I found out it was coming from the bellhousing it self. I doubt it's the wire harness connection that's on top of the pan.
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Old Jun 27, 2017 | 10:53 AM
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Originally Posted by erickk120
Are you sure it isn't coming from the bell housing? I'm saying this because I have a similar but way minor leak, at first I thought it was the pan gasket or the shift lever seal, I replaced both to no avail. It was then when I realized it was coming from the bellhousing area. The leak on my 4l60e seems to be either torque converter or pump related, when it leaks the fluid travels to and around the pan gasket and shift lever area so it makes it look as if it is the pan. I blasted it with brake cleaner and put some bits of napkin between the bellhousing and tranny where there is a groove so the oil would soak it. and wouldn't go anywhere else that's how I found out it was coming from the bellhousing it self. I doubt it's the wire harness connection that's on top of the pan.
I'm going to replace the pan gasket. I think I would have seen the evidence coming from the bell housing but I could be mistaken. I considered the converter not being pushed in all the way on installation.
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Old Jun 27, 2017 | 11:01 AM
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I use the sturdy felt gaskets and even reuse them if less than a year old. (I open the pan frequently for experimentation and learning purposes.) They and the pan don't deform if you over-torque by a bit. Not a fan of the cork gaskets and definitely not of the rubber gaskets.
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Old Jun 28, 2017 | 01:44 AM
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I was told the transmission might not be venting properly and removing the dipstick would prove if this is true. Anyone have experience with that? Still waiting on parts to arrive
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Old Jul 2, 2017 | 07:43 PM
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Looks like the leak was coming from the wiring harness on the passenger side of the transmission. The clips must be broken which made the leak appear to be coming from the dipstick tube and the pan gasket.

After I got the car a few more feet in the air and some better lighting I was able to find it.
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