# Transmission leak

**URL:** <https://boards.straightdope.com/t/transmission-leak/801133>\
**Category:** Factual Questions\
**Created:** [November 9, 2017, 6:58pm UTC](https://boards.straightdope.com/t/transmission-leak/801133 "2017-11-09T18:58:44Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Chevydriver07](https://avatars.discourse-cdn.com/v4/letter/c/b782af/32.png) [@Chevydriver07](https://boards.straightdope.com/u/Chevydriver07)\
**Post date:** [November 9, 2017, 6:58pm UTC](https://boards.straightdope.com/t/transmission-leak/801133/1 "2017-11-09T18:58:44Z")

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I drive a Chevy Avalanche. Tranny is leaking from the torque converter housing plug. I’m assuming this is also called the inspection cover. It pours out when the truck is running only. And ideas on what this could be? Thanks in advance.

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**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\
**Post date:** [November 9, 2017, 7:57pm UTC](https://boards.straightdope.com/t/transmission-leak/801133/2 "2017-11-09T19:57:24Z")

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> [@Chevydriver07](#):
>
> I drive a Chevy Avalanche. Tranny is leaking from the torque converter housing plug. I’m assuming this is also called the inspection cover. It pours out when the truck is running only. And ideas on what this could be? Thanks in advance.

from what I’ve been able to find, when that happens on the 4L60E transmission it could be just the front (input shaft) seal or the torque converter/pump bushing.

source: [HELP URGENT!! 4l60e leaking from bellhousing! - LS1TECH - Camaro and Firebird Forum Discussion](https://ls1tech.com/forums/automatic-transmission/1738381-help-urgent-4l60e-leaking-bellhousing.html)

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**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\
**Post date:** [November 9, 2017, 8:05pm UTC](https://boards.straightdope.com/t/transmission-leak/801133/3 "2017-11-09T20:05:40Z")

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Yeah, the front seal and converter seal are the main suspects. Not expensive parts, but it requires the removal of the transmission to fix it.

Dennis

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**Author:** ![SigMan](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@SigMan](https://boards.straightdope.com/u/SigMan)\
**Post date:** [November 9, 2017, 8:16pm UTC](https://boards.straightdope.com/t/transmission-leak/801133/4 "2017-11-09T20:16:02Z")

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Yep, as the retired auto transmission mechanic, it’s the front seal and it required pulling the tranny to replace it. It’s possible that the spring around the seal broke.