Transmission fluid change...fail! Few ???s

[mentalattica]

This past weekend I decided it'd be a good idea to change my trans fluid and filter in the Louisiana 100+ degree heat in my driveway at hight noon lol. Not such a good idea after all!

I've read lots of info saying you need to drop the Y pipe in order to get clearance for the pan. After looking at the pan and the clearance, I thought there'd be no way I'd have to drop the exhaust! It really did look like it would fit. So I cracked the bolts, let her drip for a while, then went on to drop the pan. Of course the pan gets caught on the exhaust pipe and no amount of wiggling would free it.

Here's my problem: I break out the long extension and 1/2 ratchet to hit the exhaust. Yea, those bolts weren't moving. I sprayed them with penetrating oil AND used my jack handle as a cheater bar still nothing! Not wanting to snap the bolts I gave up and put the pan back on losing about 2 qts of fluid in the process. So I guess it wasn't a complete fail, I did manage to get 2 qts of new fluid! lol.

I've been calling around to different dealers and get varying prices $180-$270. All of the dealers told me they don't typically drop the pans and change the filter, they prefer to do a machine flush. When I asked why I was told "per GM's specifications if the filter has enough particles to cause any flow problems the transmission is toast anyway." I've never heard that before, anywhere, ever. I thought that was the point of replacing the filter?

My questions are:
1. What are you guys using to break the bolts on the Y pipe? How likely is it that the bolts snap?
2. Is the OEM gasket reusable?
I couldn't tell what kind of condition my gasket was in since I couldn't get the pan completely off so I put it back on as it was.
3. Would you trust these quick lube places to do the job on your trucks?
I would think the quick lube places wouldn't have Dex6 but would have the multi vehicle dex/merc fluid (does that even matter?)
4. Do you think it's worth paying someone else around $200 to do the job?

5. What the hell is the hose that runs above my transmission and drains under the truck for? It looks like it exploded at some point and is spraying on my U joint. I'm assuming something to do with EVAP?

 

[TheAutumnWind]

I don't trust quick lube places. I am doing my own this weekend (hopefully). Adding an external filter too so I don't have to deal with the pan after this.

 

[JML07denali]

I will be attempting this method in the next two weeks. It looks the like this might be the most effective way.

http://www.gmfullsize.com/forum/showthread.php?t=179148



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[Deephaven]

I'd NEVER let a quick lube touch a 6L80.

You need a new GM filter
You need to pump out the fluid in the heat exchanger
You need a new gasket
You need to fill it 2 quarts above the dipstick. 6L80's starve themselves under high acceleration. When they starve, they die. Regrettably I just killed mine since I didn't know that. No QLT place will ever do it right, no way no how.

 

[justaspade]

Tranny Fluid Change

Ok, I know I don't post much but I lurk often for advice. Onto the fluid. I changed mine this past March when I purchased a used '07 Tahoe. Although, I did change the exhaust to a catback, so I'm not sure if that makes a difference but I used a large wrench to GENTLY pry it down by the muffler. Just enough get the pan out. It is tight but can be done. Also, I flushed the tranny. Now, before anyone says anything bad let me explain how. First you need a helping hand. With the pan removed and a large drain pan underneath, remove the old filter. Cut the filter at the neck, placing the cut neck back into the tranny with a 3/4 (I believe) inch high pressure hose attached to the neck. The idea is simple. A transmission pulls fluid through a filter and drains it through the tranny. With that said, load up a clean 5 gallon gas can with transmission fluid. I used 17 quarts. One person in the truck and the other with the 5 gallon container dumping into the hose. Shift through the gears IN PARK a few seconds at a time. The tranny will pull the fluid from the container forward, not backwards, just as it would naturally. Just be sure your hose is tight on the cut neck. Do this until the gas can is close to empty. Voila. Fluid changed through it's natural course. Put the new filter in, replace gasket, GENTLY PRY the y pipe and rebolt. Hopefully this helps. One added piece of advice. Replace the trans pan with a deep pan and a drain plug. Yes, I know that when you drain the pan this does not do a complete fluid change. But if you could pull the plug, say yearly and only replace 4-5 quarts each year, in theory, you will flush your tranny every 3-4 years without ever dropping the pan again thereby saving you a headache and a filter every 100,000 miles.

 

[08grey]

I'd NEVER let a quick lube touch a 6L80.

You need a new GM filter
You need to pump out the fluid in the heat exchanger
You need a new gasket
You need to fill it 2 quarts above the dipstick. 6L80's starve themselves under high acceleration. When they starve, they die. Regrettably I just killed mine since I didn't know that. No QLT place will ever do it right, no way no how.

Fill 2 quarts extra? Where you get that?

 

[Deephaven]

Fill 2 quarts extra? Where you get that?

There are 3 places on the web that build strong 6L80's.
Century, Circle D, and PATC (although nobody trusts their builds) and all of them recommend an extra 2 quarts per the dipstick.

In a non-performance application you may not starve the transmission under acceleration as much as in a modified truck, but I personally wouldn't risk it. I didn't know and literally a couple pulls with my new motor and my "full" transmission now has MONSTER flare on the 1-2 shift. Currently just in order to drive I have to pull a crap ton of timing at shift and start the shift around 3500rpm from 1-2. It sucks.

6l80etuning.com will also recommend 2 extra quarts.

After spending the past month trying to decide where to spend my money on a built 6L80 I'd personally run like hell from anyone who doesn't recommend the extra fluid.

 

[mentalattica]

...I used a large wrench to GENTLY pry it down by the muffler. Just enough get the pan out. It is tight but can be done.

I actually unbolted the exhaust at the rear and tried to pry it, I only got maybe a quarter inch out of it comfortably.

 

[Deephaven]

Good excuse to add the ARH headers. No problems getting down the pan after