Want to flush Transmission w/high miles. Good Idea?

[PuroPinchePedo]

That would probably be fine. Do you plan to tow with it or anything. Heat is really what kills the trans. Mines been very well taken care of that's why I'm on the fence about it. what trans do you have, 6 speed or 4 speed. My friend is a world class gm tech and he said 07 6 speeds are the ones to watch out for otherwise they are all pretty reliable.

Nope. It's totally stock now. It's 2wd and I do plan to put a 5inch lift and up the tires to 33's. That's a little later down the road. For now, it's just my to and from work vehicle, nothing more. I'm not sure about the trans. I'll need to confirm.

 

[ta07hoe]

Nope. It's totally stock now. It's 2wd and I do plan to put a 5inch lift and up the tires to 33's. That's a little later down the road. For now, it's just my to and from work vehicle, nothing more. I'm not sure about the trans. I'll need to confirm.

Does it have 123d or just d and you can select gears with the push button

 

[PuroPinchePedo]

That would probably be fine. Do you plan to tow with it or anything. Heat is really what kills the trans. Mines been very well taken care of that's why I'm on the fence about it. what trans do you have, 6 speed or 4 speed. My friend is a world class gm tech and he said 07 6 speeds are the ones to watch out for otherwise they are all pretty reliable.

When I run the vin check it shows "6-speed transmission A". Just has "D" no 123.

 

[06Escalade]

There really is no such thing as a "flush", its actually an "exchange" of fluid. Old Fluid is pumped out, new fluid is sucked in using the transmission pump and cooler lines. The machine is not forcing or creating any additional pressure inside the transmission. It supplies new fluid, catches the old fluid, and has a shutoff. all it does. You can do the same exchange in your garage very simply as stated above. Much easier than dropping the pan (for me anyways, had to drop the exhaust to get the pan off).

People claim a "flush" ruined their transmission. False, the transmission was already ruined from neglect or wear. They waited too long to do anything. Then when they had the fluid exchanged it it slipped. Because the same grit and junk that was helping the worn clutch pack shift and grip was now smooth as butter. In some cases worn out clutch packs can go a little bit longer before they fail if you keep the soot grime and **** between the plates. But that is the exception, not the rule. I exchanged 4 gals of Maxlife in my garage at 125k and it shifts better than ever. its at 140k now and I'm thinking about doing it again. Not because I have to, but there is definitely some cleaning going on.

Really no point in dropping the pan for 4qts and a filter if your not changing all the fluid IMO. You will just gunk up the new filter with old fluid. If all is good and you're not taking emergency measures because of a problem do the exchange (flush), should be ok.

 

[1_8TTony]

There really is no such thing as a "flush", its actually an "exchange" of fluid. Old Fluid is pumped out, new fluid is sucked in using the transmission pump and cooler lines.

People claim a "flush" ruined their transmission. False, the transmission was already ruined from neglect or wear.

This is exactly correct.
I buy/sell vehicles every few weeks...........it's what I do every time I pick up a used car or truck with auto trans. I perform the fluid exchange myself. If if the trans slips after the fluid exchange, I replace the transmission completely.

Claiming that a "flush" ruined the trans is not exactly right.......I look at it like this, the "flush" exposed an unknown bad trans situation.

 

[rv8pilot]

Last year I acquired a 2001 Yukon XL (pictured) with 235,000 miles. The previous owner had never changed the trans fluid or anything else besides the engine oil. It was not used hard, very little towing, numerous cross-country trips and the local runs. I flushed the trans with about 3 gallons of standard fluid, ran it for a few hundred miles and flushed and replaced that with synthetic. It shifts fine, is quiet and has zero slip. There is some looseness apparent when shifting from forward to reverse but nothing alarming. Obviously it won't last forever but so far it looks like there is still a good bit of life left. The original fluid was not even that dirty and had little odor, when I dropped the pan to change the filter the bottom of the valve body was clean and there was very little crap in the bottom of the pan. Says something about synthetic fluid.

 

[ta07hoe]

you can run 50 gallons of fluid through it but the filter will still be old. I'd drop the pan change the filter. The old shit will be stuck in the old filter. Old fluid will not clog up a new filter. If it's that bad you have bigger problems. You can put the return line in a5 gallon bucket and with it running keep Filling it as it pumps out

 

[jnicks01]

Just hit a bit over 100k. Changed plugs, wires, front/rear differential fluid, drain, filter, and fill on trans, transfer case fluid, coolant, and my belts. Runs amazing afterwards. Plus the piece of mind is worth more than it costs. I was even able to get the dealer to do it for under 1K with me supplying many of the parts which were a few hundred! They must have been slow.

They really didn't have much of an opinion on whether it is a bad or good thing to completely change it. Doubt they did a total 'flush' though. My fluid was pretty clean when it came out i guess.

 

[Meccanoble]

you can run 50 gallons of fluid through it but the filter will still be old. I'd drop the pan change the filter. The old shit will be stuck in the old filter. Old fluid will not clog up a new filter. If it's that bad you have bigger problems. You can put the return line in a5 gallon bucket and with it running keep Filling it as it pumps out

Agreed and the magnet needs to be cleaned off.

 

[dross99_si]

Personally, I've always been leary of flushing and our local GM dealer said they don't recommend flushing either. We had them change the filter and fluid and it was only $149. I totally expected it to cost more..