4L80E Maintenance

swl2126 · November 3, 2003

I started to the task of performing routine maintenance on my 2500HD 4L80E transmission. I've been doing this for years and normally the filter kit (filter and pan gasket) runs $30 or $40. To my amazement, the filter alone is $54 and the gasket (which is supposed to be reusable) is $41. Including fluid, the parts alone costs over $100. Something wrong with this picture???

Chevyfreek · November 4, 2003

I have my 4L80E serviced at the dealer every 30,000mi and the cost for the complete flush and fill was $98.00 or so. I would suggest having the dealer service it if the parts are going to cost that much. It does sound kind of high to me.

JimWilson · November 5, 2003

A flush and fill does not change the filter though, so that will add to his cost. But I do agree that for parts alone those prices seem kinda high.

Chevyfreek · November 5, 2003

That is news to me. What is the point of having the trans service done if they don't change the filter. I was not aware of any different trans service offered that does include a filter change. I will have to look into this....

1BADHD · November 5, 2003

I have also been told......the 4L80E does not equire a filter. It has a screen. Once the engine is off the fluid back flushes teh dirt and contaminants into the pan. Where it will later get drained and changed.

JimWilson · November 6, 2003

Unless you're talking about the Allison -- which actually DOES have a filter -- when you mention "filter" and transmission together you're really talking about a screen. They're kinda interchangeable.

Chevyfreek · November 6, 2003

Ok, I understand what you guys are saying. I did not realize that the 4L80e did not use an actual filter, but had a screen. Thanks for the clarification.

Jim I was wondering where you get your Amsoil products from. I am due for changing the fluid in the front and rear diffs on my HD. I was thinking of using Amsoil and wondering if you had any suggestions as far as where to get the fluid for my truck and how much is required. Also if I need the friction additive for the rear G80 locker. I have heard it is not to difficult to change the fluid out in either the front or rear, so I was going to do it myself this time. The dealer is pretty expensive on the diff fluid changes. I think the invoice I had said they use 3 quarts of axel oil in each diff. That stuff was not cheap at $22.00 a piece. I think it was synthetic oil, since I believe that is the factory fill for my truck. i am not sure about what weight oil to use either. Any suggestion would be appreciated sir. I may decide to do the transfer case as well since I have not serviced it yet. Thanks...

JimWilson · November 11, 2003

Jim I was wondering where you get your Amsoil products from. I am due for changing the fluid in the front and rear diffs on my HD. I was thinking of using Amsoil and wondering if you had any suggestions as far as where to get the fluid for my truck and how much is required. Also if I need the friction additive for the rear G80 locker. I have heard it is not to difficult to change the fluid out in either the front or rear, so I was going to do it myself this time. The dealer is pretty expensive on the diff fluid changes. I think the invoice I had said they use 3 quarts of axel oil in each diff. That stuff was not cheap at $22.00 a piece. I think it was synthetic oil, since I believe that is the factory fill for my truck. i am not sure about what weight oil to use either. Any suggestion would be appreciated sir. I may decide to do the transfer case as well since I have not serviced it yet. Thanks...