4L80E Info Request!

I'm going to be doing a fluid & filter change on the transmission and have some general questions.

The 4L80E trans is the same as any other GM 4L80E trans? I ask because 2006 M1165 is not a vehicle for the purposes of searching rockauto, napa, etc. Does anyone know a vehicle I can use to search with?

I think I read I want Dex6?

Is the 4L80E trans pan the same as any other GM 4L80E pan? I ask because I want to find one with a drain plug.

The transmission itself is the same, so yes a civy pan will bolt up, the only question is if there is an interference issue with any of the HMMWV hardware, I would think not but I have never had a 4 speed, went directly to 6 speeds, I am sure someone will jump in and confirm or deny this.
I like to use stock depth cast aluminum pans, maybe a little more but they usually come with multiple threaded holes or at least the castings to drill for things like drainage and temp sender, and they seal well.

Mainsail said:

I'm going to be doing a fluid & filter change on the transmission and have some general questions.

The 4L80E trans is the same as any other GM 4L80E trans? I ask because 2006 M1165 is not a vehicle for the purposes of searching rockauto, napa, etc. Does anyone know a vehicle I can use to search with?

I think I read I want Dex6?

Is the 4L80E trans pan the same as any other GM 4L80E pan? I ask because I want to find one with a drain plug.

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Yea, its the same, I recently bought a pan for it. Don't forget, you can reuse the same gasket, and don't get some cheap gasket, it will leak

Dextron 6 is the correct fluid

This is the pan I went with since I had to bend my original one to get it off


This is the gasket I used, but its not necessary to replace the gasket if yours is fine.


I went with a cheaper gasket before this one and it leaked, the difference in quality from that gasket and a cheaper one is far different and noticeable.

Hummer Guy said:

Dextron 6 is the correct fluid

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Do you know if Dexron 6 is backwards compatible with the older 4L80's that use the lower number Dexron fluids?

Dieselmeister said:

Do you know if Dexron 6 is backwards compatible with the older 4L80's that use the lower number Dexron fluids?

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Yea, its compatible, GM also recommends to use Dextron 6 with any that says use Dextron III

Hummer Guy said:

Yea, its compatible, GM also recommends to use Dextron 6 with any that says use Dextron III

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Of course they do, the rights to DEX III ran out, the main reason they developed DEX VI is because they can't get any more money licensing the rights to use the DEX III name.
It has been well established that going to a full synthetic after using "regular" oils can lead to seals leaking because the molecules that make up synthetic oil are smaller.
IMHO the best advice is to use what was being used before IF you have some idea what was being used, in any case pick one and stay with it.
When GM said Dexcool was compatible (same reason) with any GM vehicle it cost them millions, and it still causes lots of issues with swollen O rings etc. so I would take anything GM says with a grain of salt, some of us remember who owns GM...

Mainsail said:

Does anyone know a vehicle year make that uses this transmission I can use to search with?

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All the later HUMMER's should work(if not I'm sure someone will pipe in).Some of the internals are different on the military trucks and the early one have the older coolant routing on the passenger side. If you are just looking for a pan it should not be a problem. The normal maintenance is drop the pan, swap filter and replace and refill. I know this does not do a complete fluid change thus I guess your desire for the drain plug??? I would also suggest you check out the previous part numbers with MAC's numbers.....It appears the very latest 4 speeds have some upgraded internal parts and there might be a batch of rebuilt 1097's out of Texarkana that have 4L85's. Good luck with your new money pit...... I mean toy!

Mainsail said:

Does anyone know a vehicle year make that uses this transmission I can use to search with?

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Good template is a 1996 chevy 3500 with 6.5


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Can we agree this is considered the "shallow pan" so I only need to buy the filter once?

Mainsail said:

Can we agree this is considered the "shallow pan" so I only need to buy the filter once?

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I do not think there is more than one filter for the pan. It uses a separate tube between the filter and trans body. Again MAC or one of the gov. supply chains is your friend!! Gasket, filter and o rings. Quality stuff.

No, not more than one filter, but my typical routine is to buy the filter, get slimed up with trans fluid, grease, or oil, then discover the filter I bought isn't anything like the filter I removed. Then I have to go back to the parts store and sort out the right filter. I was hoping to skip that last step and get the right filter straight away.

I'd also rather just run down to NAPA and pick one up- not order it.

Mainsail said:

No, not more than one filter, but my typical routine is to buy the filter, get slimed up with trans fluid, grease, or oil, then discover the filter I bought isn't anything like the filter I removed. Then I have to go back to the parts store and sort out the right filter. I was hoping to skip that last step and get the right filter straight away.

I'd also rather just run down to NAPA and pick one up- not order it.

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GENERAL MOTORS 24210468, filter.... G. M. 8677743 gasket.... NAPA in my neck of the woods shows the gasket , but would have to cross over the filter number. Just saying the quality of the parts is different. And beautiful country you live in, spent a bunch of time in Bangor and Bremerton. At least when it's not raining.

Mainsail said:

Can we agree this is considered the "shallow pan" so I only need to buy the filter once?

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There are 2 different 4L80E trans...early and late...different bolt patterns....your pic is the late one.