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Leak at AT/Diff

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Old Mar 1, 2025 | 08:09 AM
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Default Leak at AT/Diff

Moving my 2K yesterday it sprung a pretty significant leak emanating from the weep hole between the back of the transmission and the diff. %$#&^%$#!!!
Just how much of a PITA is this really? I know I have to drop the cradle to pull the diff and the source of the leak is the transmission, the puddle is ATF. Certainly seems a good time to change gearing....
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Old Mar 1, 2025 | 09:37 AM
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Sounds like the Output Shaft Seal on the Transmission. Have to get the Rear Diff off of it to get to it so yea little bit of a pain. If you keep the 4L60E bolted up to the Torque Tube don't let it drop lower than the position its sitting in. Basically keep it supported up.
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Old Mar 1, 2025 | 06:41 PM
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Merv is right. If you allow the trans to bring the rear of the torque tube down, the top rear of the engine will pivot into the firewall and break the Hell out of everything. Make sure you support the trans/torque tube well, with something secure......
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Old Mar 2, 2025 | 08:08 AM
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If you change gears. I’d recommend 3.42 or 3.73. I went with 3.73, also a YankSS converter, 3200. On the expressway, I’m cranking about 2600RPM at 76mph. I love the steep gearing. 3.90 or 4.10 might be a little to much.
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Old Mar 2, 2025 | 09:01 AM
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I went with a 3,200 Yank as well. That converter has been in there for 20 years and nearly 100,000 miles. IMHO, you can't go wrong with a Yank. I went with a stock C5 Z06 3.42 diff, and installed the beefed up/hardened (300M?) long side drive shaft. 2,600@76mph sounds right. My 3.42 turns around 2,300@75mph......
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Old Mar 2, 2025 | 09:51 AM
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Yank makes excellent stuff. Them or Circle D.

Years ago I knew a couple guys who were doing a Rear Diff in a C5Z. Told them to support the T56 up and they didn't listen. Gravity happened and that car ended up totalled. They were under the impression that the Firewall was Steel and would support all that weight. Some learn the hard way.
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Old Mar 4, 2025 | 11:54 AM
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Originally Posted by the_merv
Yank makes excellent stuff. Them or Circle D.

Years ago I knew a couple guys who were doing a Rear Diff in a C5Z. Told them to support the T56 up and they didn't listen. Gravity happened and that car ended up totalled. They were under the impression that the Firewall was Steel and would support all that weight. Some learn the hard way.
Hey merv, isnt that the old saying ya can lead the horse to water, but ya can't make him drink?!!
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Old Mar 4, 2025 | 12:30 PM
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BTW, glad to see you here, Merv. I think you'll be an asset to the forum. Welcome........
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Old Mar 4, 2025 | 12:47 PM
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Originally Posted by grinder11
BTW, glad to see you here, Merv. I think you'll be an asset to the forum. Welcome........
Thanks. I'll chime in where I can. I made a post last night of when I put the Speed Bleeder in my Z06 without removing the Slave Cyl. That one will either help people or make them wonder..
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