Automatic Tranny Fluid Changes...

So, I ended up buying a 2007 GMC Sierra 2500hd with the 6.0L and 6 speed and am curious as to if I should change the fluid myself or get a shop to do it?

Automatic transmissions are one of the few automotive parts that scare me, way too many horror stories. I am perfectly capable of doing it myself, but am wondering if there are added benefits/precautions that a shop will take? With 200,000kms on the truck, should I even bother?

I can't think of anything special a shop would do. Changing the fluid can't hurt, but apparently slushboxes can go practically forever without a change once they're broken in.

I would do a drain and refill, using OEM fluid. But I don't think I would risk stirring E36 M3 up by dropping the pan and changing the filter or anything like that.

If you just dump from the pan, you're only getting roughly 1/2 the atf. There is a way to get much closer to all of the fluid.

Disconnect the feed line to the oil cooler and put it down into a large oil pan. Start the vehicle and admire the dirty atf being pumped out from the line. Start topping up the fluid by pouring new oil into the filler. As the atf color changes from dirty and dark to a pretty and light, you've achieved done-ness. Figure on roughly 2-4 gallons atf.

foxtrapper wrote: If you just dump from the pan, you're only getting roughly 1/2 the atf. There is a way to get much closer to all of the fluid. Disconnect the feed line to the oil cooler and put it down into a large oil pan. Start the vehicle and admire the dirty atf being pumped out from the line. Start topping up the fluid by pouring new oil into the filler. As the atf color changes from dirty and dark to a pretty and light, you've achieved done-ness. Figure on roughly 2-4 gallons atf.

As much as I'm a DIY kinda person, I'm happy to pay a quickie lube place $50 to do this. I've done it a couple of times, I sit in the car and shift through the gears while they pump in the new fluid and drain the old. Easy-peasy.

Having said that, I did do it myself on the Taurus X. As foxtrapper said, you can't get it all. So I drained everything that would come out (4-5 quarts) then topped it off with new fluid. Did this 3 times over 3 oil changes. Maybe I don't have all the old stuff out, but I'm confident I got most of it, and the fluid that's in there is overall newer and cleaner than what there was before I started. But in the end, I probably should have just taken it to the quickie lube place.

I try to stick to 15-30k mile changes (drain and fill). I've done the truck 4 times.

has Bob Costas infiltrated the forum again?

changing the fluid and filter is easy, if maybe a little bit messy if there isn't a drain plug and you don't think carefully about which bolts you are going to take out when and which ones to leave in just a little bit... the filter usually just snaps into place on the bottom of the valve body- you aren't taking anything important apart.. sometimes you are laying in a quickly expanding puddle of atf while trying not to drop a pan with 4 quarts of fluid in it on your head, but i've found that it is an excellent hair conditioner if it does happen..

just drop the pan, pop the filter out, pop the new filter in, put the pan back on, and refill with however much fluid it takes to fill it back up..

Drop the pan, change filter. Top off with fluid. Disconnect cooler line, turn on truck, watch dirty fluid pumped out, pour in more fluid, turn on again, repeat until fluid comes out clean. Reconnect line, top off and warm up.

I wouldn't expect to get out of a shop spending less than 250$ to 300 bux, once you factor in the price of filter and fluid you are talking about 100$ or so in just materials.

I started to develope a stumble/shutter in the auto trans on my Ford Taurus business car. Took it in to a local shop and asked about changing the trans fluid. They use the method descibed above of adding fluid as the old stuff was being drained. My car at the time had 125 thousand miles on it. The guy said he would do it but did not recomend it. He gave me a laundry list of reasons such as the trans developing leaks with new fluid possibility the trans shifting worse or slipping then it currently was.

He went as far as suggesting getting rid of the car unless I wanted to replace a trans. I continued to drive the car and the problem was getting worse. I did some research on the internet and found a lot of people were saying the same thing as the mechanic said as well as a lot of other opinions about going ahead and changing the fluid. I was starting to think about getting rid of the car as it didn't have a lot of value left in it anyway.

While in a auto parts store for something else I went over and looked at auto trans additives. While standing there another customer asked if I was having trans problems. He recomended using some Dr. Tranny Instant Shudder Eliminator for about $7.00 bucks. The tube only contained 2 fluid ounces but figured I had nothing to lose. In less then 50 miles the shudder was completly gone and has stayed gone now for over 10 thousand miles. Bottom line is from what I have read not sure I would change fluid if the vehicle has a lot of miles.

novaderrik wrote: changing the fluid and filter is easy

I don't think anyone's concern is how difficult it is I'd just rather run this truck to 300,000kms without changing the fluid compared to changing the fluid and randomly having it strand me on a 5500km trip towing a trailer. THAT is the reason for the question. It seems to be a very small amount of people who actually get their tranny fluid changed when recommended on the service intervals, so I was curious :)

i change mine at recomend service intervals or sooner if the fluid starts to discolor or smell. But i also have access to a flush machine that pumps 16 quarts through the system to make sure it cleans everything. Im big on maintnence because i find it much cheaper then replacing parts later. A proper flush removes alot more dirt and old fluid from the system then just a filter change.

If its over 150k miles id recomend a high mileage universal atf like the max life.

TunaDad rebuilds automatics for his bread n' butter at his own shop.

He says rumors saying not to change the fluid and filter help keep him in business.

He also uses Dr. Tranny's shudderfix, and I think it's the only additive of any sort I have ever seen him add to any vehicle ever.

Change the filter. They get plugged up with clutch debris etc. This causes the line pressure to be low resulting in further clutch slippage.

I "re built" several transmissions by changing just the fluid in the pan and the filter. This was on trade ins because of transmission problems. Buick dealer.

The whole "changing the fluid will kill it" thing is an urban legend, if it was in bad enough shape that fresh fluid magically killed it, it would have been dead in a week no matter what. No magic in an automatic, its just a bunch of hydraulic cylinders and valves and some wet clutches, none of those things are happy swimming in their own E36 M3.

I've always changed my fluid every 30k miles.

However I'm still concerned about trans flushing. I've heard rumors, but not sure if they are true.

I recently changed the fluid in my GMC van's transmission (and swapped in a new valve body). Drop pan, change filter, re-fill, drive a day or two, drain again (this time sucking it out the dipstick tube) and re-fill.