New Guy With A Transmission Question

[3/4gmc]

Hi everybody! I am new to the site as of today. I own a gasoline '06 3/4 ton GMC with the 4L80e transmission. I recently purchased a remote transmission filter setup to install on the transmission cooler line. My question is which of the lines going to the transmission cooler is the out line, and which is the return line on the 4L80e? I need to know which direction the ATF is flowing to know which way to hook up the lines. Please help. Thanks.

[txab]

I believe the top line out of the radiator is the return. One way to always be sure is to disconnect a line put a length of rubber hose on the line and one on the fitting, put both into a jar. Have a buddy crank the engine and observe which line spits out fluid.

[SeirraRR]

Welcome to the site

[pwall]

Welcome!

[99silveradoz71]

Howdy

[amtz.zero]

Welcome.

[alwcurlz]

Hi everybody! I am new to the site as of today. I own a gasoline '06 3/4 ton GMC with the 4L80e transmission. I recently purchased a remote transmission filter setup to install on the transmission cooler line. My question is which of the lines going to the transmission cooler is the out line, and which is the return line on the 4L80e? I need to know which direction the ATF is flowing to know which way to hook up the lines. Please help. Thanks.

 

It wont matter which line you put the filter on unless you're planning on a bypass. If that filter ever gets partially clogged and you don't know it, you'll have quite a reduction in cooling ability for that transmission. May I ask why you're putting an inline filter on?

[3/4gmc]

I am putting the filter on to hopefully increase the life of the transmission as much as possible. The micron rating on the screen type in the transmission is no better than 100-150 or so at best from what I can tell. This won't catch all of the crap that can eventually end up wearing on parts. The filter system that I am putting on made for this application and will catch any of the unwanted particles as they come through. It is a Perma Cool brand that I got from Summit. My pickup only has 20,000 miles on it now and I want to put this on early so that I can get as long of use as possible out of it. Consider it preventive maintenance.

[r1byker]

I'm curious about how often you're planning on changing the transmission fluid; I hear that's the best way to prevent transmission trouble. I just picked up a 2010 Sierra with the Allison transmission; hence, I joined this forum. But I've been towing with a 2005 Suburban and I change the transmission fluid every 35,000, which is sooner than the recommended 50,000 for towing, but I figure better to be safe than sorry.

[3/4gmc]

I already pulled the pan and drained as much fluid as possible, around 6 qts., at 18,000, but I still plan on changing fluid at around 50,000 with a dexron VI synthetic if I can find it. Putting on the filter won't change how often I change fluid. It's really just for PM. Maybe it's won't help much, but it gives me peace of mind that the transmission is getting filtered a lot better than it would otherwise. I may be wrong but I think that the allison comes factory with an external filter similar to the one that came in the kit that I bought. If so I'm sure there is a good reason for that.

[MS3DALE]

I may be wrong but I think that the allison comes factory with an external filter

 

Correct,The Allison has both....an external filter,and an internal filter inside the pan.