Worries about 4t60e fluid/filter change...

[Spankdamonkey]

I really wanna change my tranny fluid and filter as the car has 104k on it and it has never been replaced, but I have some worries concerning the procedure: Everywhere I go I seem to find people talking about transmission problems just a few hundred miles after a DIY transmission fluid/filter change, but by that same notion I'm not sure if I trust a shop to do it either, as they are just as likely to purposely make the trans fail so as to get me back in there and purchase a whole new one. My main concern is that the fluid has been in there so long that new fluid may just outright cause the trans to not shift anymore.......

The car shifts just fine right now, I just wanted to do this as a preventative measure against failure in the future. Should I take the advice of others on the saying "If it ain't broke, don't fix it"?

I have siphoned out roughly 4 quarts in the past without ill-effect, so I may just do that again to avoid the inherent problems with dropping the pan.

What does everyone think?

[SappySE107]

What color is your fluid. If it has never been changed, it should be brown and smell burnt. GM makes a conditioner you should use with the fluid change.

A shop can hook it up to a machine to get all the fluid out. A DIY procedure will leave some in the valve body and the converter. They should replace the filter afterwards but most placed swap it first and run the old shit out through the filter while the new is put in.

You aren't doing any good without dropping the pan and changing the filter.

[Spankdamonkey]

I suppose you are right....but can you see the dilemma? I have heard horror stories about regular maintenance procedures gone terribly wrong at these shops. And since they don't say "if we screw up your trans while changing out the filter, we'll fix/replace it" that leaves a very unsettling feeling that they may give me back a car with a non-functioning tranny, as it is no big deal to them anyhow.

[Spankdamonkey]

Oh and for the record, since I had siphoned out some of the fluid in the past and replaced it (and added a bottle of slick 50 transmission treatment to it in the process) the fluid is not very discolored at all.

So the real question is, what is the potential for something going wrong in a DIY filter/fluid change?

[sharkey]

we see nothing but bad things from lube shops doing flushes on transmissions. when you remove all the old oil and replace it with fresh using a cooler line flusher and the flush additive, it ends up breaking down and loosening the varnish and deposits that were previously doing no harm. now the loose particals are floating around and end up jamming the valve body up and getting into the clutches, and cause lots of issues. many transmission shops have put thei flushers aside and do a regular pan drop service instead.

pulling the pan off and changing the filter isnt that hard. with the pan off, all you have to do is pull the filter down (may have to wiggle it a bit) and itll come off. just push the new one striaght up. clean the pan up with solvent or brake clean. if it has a cork gasket, you need to set the edge of the pan on a hard surface (like the edge of a work bench) and hit the holes with a hammer a couple times to make sure the pan is flat. if you have a re-usable pan gasket (they are thick, black hard gaskets, the pan may also say "re-usable gasket" on it) you dont need to do this. when putting the pan back on, start all the bolts before tightening them up. you want to tighten them with one hand around the head of a ratchet and just snug. a speed handle is a better choice if you have it, just use one hand on it and get them good and snug. with the re-useable gsket you will know when its tight. with a cork gasket, tighten it till it starts squishing, but dont tighten it till it squishes out. also DO NOT USE ANY SELAERS ON THE GASKET!!! i see this quite often, all it does is cause leaks.

if you dont want to do it yourself, find a reputable shop and take it in. a reputable shop is not going to damage your transmission so you need an overhaul.

[SappySE107]

That is the case for a neglected trans, as we are discussing. I have had only good results from mine when I had mine flushed.

[Spankdamonkey]

A flush??? Oh good LORD no lol. I just wanted a basic filter and fluid drain job. But what was said about the neglected trans.....I got ahold of the car when it already had 98k on it...so I really don't know for sure how it has been treated (it was used as an undercover police vehicle for some time, and was acquired from a DUI case before that, so all this would lead me to assume they beat the hell outta it) This furthers my fear of this.

But here are the logistics: I KNOW the pan has to be covered in sludge. So if I don't do something about it now, then it will fail me later, perhaps much sooner than it should. On a serious level though ?¿?What are the odds of my trans going south as a result of a fluid/filter change?¿? If it is a flush that damages a neglected high-mileage tranny, a simple drain shouldn't hurt it right?

[Spankdamonkey]

But wait...aren't the detergents in the new tranny fluid strong enough to remove the built up varnish and cause the same problems outlined above anyhow??? I hate life.....this is one of those decisions that if made wrong will haunt me forever......a "simple" transmission fluid and filter change.

[Trannyman95]

You mention syphoning some out before, was that on this same vehicle? If so, or even if not I wouldnt worry about it. Its not such a shock to the trans when you replace half of the old fluid with new. When you have it flushed you are removing all of the old fluid. As fluid ages it chemically changes and the friction materials and adhesives that hold the clutch lining on the clutch plates adapt to this over a long period of time. Just doing a filter-fluid change is safe since you are mixing new with old, then down the road you can do another service again having another 50-50 mix of new and not so old and you give things time to accept the newer fluid. The biggest problems, at least from what I have seen and experienced around here, is that people who do trans flushes never check fluid levels after the service. The think they replaced everything that came out, but dont know if it was low to start with. So now you end up with new fluid and additives to losen up deposits and being 1-4 quarts low on fluid because nobody checked and then a few weeks or even days later your trans takes a crap because its been slipping and the valve body is contaminated, and again a big chemical change of fluid shocking the frictions. Flushing is fine if its done properly and often and the fluid level is checked. For you though dropping the pan and replacing the filter and refilling it properly should be just fine. After you drive it re-check your fluid level and make sure it is full.

[Spankdamonkey]

You mention syphoning some out before, was that on this same vehicle? If so, or even if not I wouldnt worry about it. Its not such a shock to the trans when you replace half of the old fluid with new. When you have it flushed you are removing all of the old fluid. As fluid ages it chemically changes and the friction materials and adhesives that hold the clutch lining on the clutch plates adapt to this over a long period of time. Just doing a filter-fluid change is safe since you are mixing new with old, then down the road you can do another service again having another 50-50 mix of new and not so old and you give things time to accept the newer fluid. The biggest problems, at least from what I have seen and experienced around here, is that people who do trans flushes never check fluid levels after the service. The think they replaced everything that came out, but dont know if it was low to start with. So now you end up with new fluid and additives to losen up deposits and being 1-4 quarts low on fluid because nobody checked and then a few weeks or even days later your trans takes a crap because its been slipping and the valve body is contaminated, and again a big chemical change of fluid shocking the frictions. Flushing is fine if its done properly and often and the fluid level is checked. For you though dropping the pan and replacing the filter and refilling it properly should be just fine. After you drive it re-check your fluid level and make sure it is full.

That does make me feel a little better.......even in a worse case scenario where the valve body becomes contaminated by freed up varnish deposits, can a subsequent tranny flush get rid of the varnish particles that become lodged in the valve body?

[Trannyman95]

This is where there is often confusion and missunderstanding. A transmission flush is not what it is led up to be. Basically the fluid inside the transmission is replaced with new fluid so there is really no flushing going on. A lot of people thing its a machine that pressure washes the inside of a transmission with detergents and new fluid, when it is nothing of the sort. If there are contaminents inside the transmission then taking it apart and cleaning it during an overhaul is the only way to clean it. I know with the BG systems, ans well as Wynns flush machines, you poor an additive into the trans and let the vehicle run for a while to get warmed up and you run the vehicle in gear to get the additive throughout the trans to clean it and losen up particles that cling to parts. After this the flush machine is hooked into the cooler line, if not already installed, and goes into a mode that replaces old fluid with new fluid at the same pressure it came out of the transmission. Having rebuilt a LOT of transmissions and quite a few that came from shops hoping to flush new life into a transmission I can say that it doesnt clean up the inside like they claim, but most people think a flush will rejuvinate a dead transmission which is far from the truth and most of us know better from hearing horror stories. Once in a BLUE moon an additive can help a sticky valve body work like it should, and Lubegaurd Red additive is about the only thing I have found that helps, but the truth of the matter is if there is debris causing sticky valves then there are larger problems to worry about and the additive is only a bandaid fix. You should be fine doing a filter-fluid service and shouldnt have to worry about any of this.