Noise when turning... Hmm?

[Jayce]

Just to isolate a little confusion: What is it when doing a "flush" that can damage a neglected transmission? I've heard flush used in two different circumstances. One with detergents, and one without detergents that uses a machine to feed new fluid in and ultimately replaces 99% of the old transmission fluid. So if I had a high mileage neglected vehicle and I did a 99% fluid swap, would that be catastrophic to the vehicle? Or would it likely handle it better than doing a flush using detergents and solvents?

The more I think about it, the more I think I'll just get the mass fluid change and forget the filter. The garages I spoke to said at least 90% of their customers tend to let the filter lapse every other change, which is where the figure above came from - 50k fluid, 100k fluid/filter. I'd certainly like to do all of it, but 100 bucks is far easier to swing right now with settlement on our house in 2 weeks... every little bit counts...

 

[C0RR0SIVE]

When flushing a transmission, what can cause it to fail is heavy clutch build up in the pan, clogging the filter when it gets stirred up. On top of that, the new fluid will dissolve old varnish that is now protecting worn out clutch bands.

But that is on a transmission that has been ignored it's whole life. When a flush is performed they can not (there is actually a law that prevents this from being legal) flush your transmission with anything other than an approved compatible fluid. Most shops use regular old transmission fluid, a few gallons worth to do the flush. The transmission fluid contains solvent/detergents that do the cleaning through its life, that is what they use to do the "cleaning". A flush is just a fluid swap, that involves a whole lot of fluid in the end.

 

[Jayce]

I see. The dealership I called specifically said they use some sort of detergents within the system to clean it, then they flush it out and put in all new trans fluid. Meanwhile, every other Jiffy Lube and mom/pop garage in the area told me their version of a flush isn't using any sort of detergents at all, but just systematically draining the trans fluid while replacing the system with new trans fluid as the vehicle runs. They said it uses the transmission's own pumping power to do the swap and you just wait for a bit until it's done. All shops told me they use Dexron (6??) I believe.

What the dealership told me with detergents gave me a visual of an empty transmission being filled with dawn and then power washed internally until it was clean to fill up with regular trans fluid. When I hear "detergents and solvents" I can't help but to think of some sort of cleaning soap being used.

But there again, the Jiffy Lube + mom/pop shops = "flush", while dealership = "flush". That's where I still got confused.

I just find all of this fascinating... I would never associate a fluid like transmission fluid as having a more sensitive life span. "Change it at proper intervals, or if you let it go entirely too far, just forget it and don't change it at all, because that's less catastrophic to the internals." That being said, where do you personally draw the line? If you were given 4 used cars, 50k, 100k, 150k, 200k, which ones would you service and which ones would you not?

That being said, let's say I flush an older neglected trans. Now I have to repair it. Is it normally just the clutch packs that need servicing, or are there more components that come along as part of the rebuild process?

In other news - today I let the vehicle warm up a bit. Not so much to where it was maximum idling temperature, but enough the needle was about halfway up the scale. The spot I park in is on a slight slight hill and I had to go uphill to get out of the spot. I was babying it because I could feel it wasn't grabbing the drive gear as I crept out of the spot. Once I got flat, I felt a very small tug and off we went in gear just fine. Once I even put it back in park and then down to drive thinking maybe it would re-initiate the gear sequence a little easier, but I still felt the rev up and slip, as if I was in my stick shift car with the clutch halfway engaged as I was giving it some gas to creep forward.

Based on what more I'm reading, I wonder if it would be wiser to, instead of doing a 100% fluid change by doing a flush or whatever the garages in the area told me they do, to instead just get the filter changed. After all, if I get the filter changed, I'll be losing a good amount of the old fluid anyway. So if I go that route, even though the transmission isn't insanely aged, I'll still cut out some of the "shock" by using all new fluid and in the process I'll get a new filter installed. Or is that theory foolish?

All of this is making me miss my manual Elantra that other family is driving now due to a vehicle shortage in the family. Then again, I'm super guilty of not changing the trans fluid there either... and I'm at 165k on it... Did I fail?

EDIT - Called two Saturn service centers. They recommend a flush. (EDIT II: Even Saturn customer service recommends a flush, citing that the field techs are their eyes and ears and what they recommend is almost always out of the book from GM direct). They said it's the flush process that some quick lube places do that can do the damage I'm reading about on Google. One of them also said he believed my trans filter was not designed to be replaceable, but simply cleaned when necessary.

The confusing part is, if the trans fluid itself is a built in detergent, and the flush systems quick lube shops use aren't pressurizing the transmission to pump the fluids in/out (the trans does it on its own power) how is that harmful?

djflas;kdjakls;ddafsdfasdfajhwhakl

 

[C0RR0SIVE]

Well, back in the 90's when small oil change shops got those machines, they got machines that forced fluid through the transmission, this resulted in blown seals and such, that's part of why the myth of never doing a flush came up. A lot would also use the WRONG fluid, they buy in LARGE amounts of bulk, of the cheapest they can buy. Dodge normally uses there own stuff, ATF3/4, you throw dex in, say bye bye to the transmission 10k later. Most every brand uses there own fluid, but some fluids are cross-compatible. I know a LOT of people, including me, that just drop their pan, replace the filter and put some fluid in, which is actually over half of the fluid in a transmission in most cases, that way we know what fluid we are getting. So honestly, avoid anyone but a local AAMCO that actually has GOOD ratings (*******s destroyed my intrepid in the end using dexron) or go to the dealer for transmission servicing. I don't trust little shops, nor mom and pop shops unless they are willing to show me the fluid with the label on it, and a book that says what they are doing is what the designers recommended.

Honestly, if under 100K miles, I go by the book if I just got it, but I dont trust the last person to have taken care of it, so I go the route of doing every single maintence item, including a flush. If we had a book on your car, we could rule out if you had the filter or a screen. But if the book calls for a flush instead of a drain, filter replacement, and refill, I will do the flush upto 100k, but I make sure if it has a filter the filter will get replaced at 100k. But, GM master mechanics are some of the smartest people I know when it comes to car maintenance.

Also, GM cars/trucks (saturn is GM) use Dexron, the only Dexron that should be used anymore is Dexron VI (6?) or is that IV? ANYWAYS, proper fluid is a must, as the clutch packs are designed for such fluid.

In most transmission rebuilds you have "soft part" damage, which is mostly just clutch packs, you have like 3 or 6 little discs for every gear you have, that's a lot that can be ate up, and the cost depends on region. In kentucky, a soft part transmission rebuild is ~1400 at a CHEAP crap shop (they actually ruined my transmission by putting dexron in, mine was designed for ATF4), when in PA, I had a planet carrier fail, that is a hard part failure (and VERY damn rare), $4500, if it was just clutch packs again, it would have been $2500 in PA.


BTW, the whole "cleaning" comes from the fresh fluid that is getting poured in, trust me, transmission fluid is a VERY powerful cleaner, it has to be, it has to go 40k+ miles while trying to keep your transmission clean on the inside, and if done at proper time, they are VERY clean compared to what your engine is, on the inside. If you are getting slipping and it's starting to do that whole kick thing, you need to take it to the dealer and let them get it done for you.

BTW, a manual, they are capable of putting up with neglect as they mostly use that heavy gear lube, and have only one clutch that normally from my understanding isn't sitting in stuff that can ruin them if left too long. Though proper service is nice.

 

[Jayce]

The problem is, the manual doesn't specifically say flush. It reads:

Change automatic transaxle fluid and
filter (severe service). See footnote (h). (50,000)

Is that flush? Does change mean drop the pan and change half of it? Does change mean change 100% of it? I just don't know what they're referring to.

The plot thickens. I called the most reputable transmission place around (I can't believe I hadn't remembered them sooner) and asked them what they recommended. The mechanic I spoke to said they stopped doing flushes about 10 years ago when more and more people began coming in with problems following a trans flush. He said with newer engines being made with various aluminum parts, he wouldn't consider it. He said it's entirely my call and if I want a flush I could go to a service center that does it, but he said he wouldn't do a flush under any circumstances. He believes in my case dropping the pan and getting topped off with trans fluid would be the way to go, but re-iterated I can go either way if I so choose. He said they don't use Dex, but they use some other kind of transmission fluid that's synthetic and deemed "GM Compatible" by General Motors. I forget the name. I thought he said Mako 5 or something?

I called another reputable transmission who's been around forever. I thought these guys closed up but here they just moved locations (Cottman Transmission) Pretty sure I'm going to drop the van off tonight for these guys. He said he doesn't really do flushes anymore but sees where they can sometimes be beneficial, despite the fact he rarely thinks they need to be done. He said they would check out my van for free, and advised I drop it off the night before so they can drive it cold in the morning and see if they can duplicate exactly what I'm seeing. He said they can also drop the pan and change the filter and check things out and top it off when it's all said and done, but he said their diagnostics should dictate what route to go, at which point I'd get a call before they would do anything that would cost me a dollar. Since my brother has off tomorrow (which means I can have my Elantra back for the day), I'll go that route. So far this guy also happens to have the cheapest pan drop/filter replacement/fluid top prices around @ 120, where everyone else was 140, 150, 179.

If only I was moved in and had a nice 3 day weekend on my hands I'd love to take a wack at this myself... But right now all I can think about is the scary risk of not having the van come move day, since uh, I sorta need it.

 

[C0RR0SIVE]

Don't use anything other than the dexron, trust me, the reason it don't use the Dexron name is because GM didn't give them a license to use the name.

I like the one that is offering to check it out, drop the pan and replace the filter, but only if he is willing to use the actual Dexron fluid, honestly, it doesn't hurt to have SOME of the old fluid in there, you might just wanna have the fluid and only the fluid changed out a little bit before the next service date since it would be 50% worn, unless this guy is willing to try and drain your torque converter and do a 100% refill.

BTW, is that the owners manual your looking at, a haynes, or the FSM? Haynes is mostly based on the FSM, but the FSM is what should be gone by most all the time, Haynes is the FSM but made simple and easy enough for a home mechanic to get the job done and still be acceptable if done right. User manual is just a guideline and toned down so people can get the work done, and is wrote for if your taking it to a GM authorized dealer that will go by the FSM.


BTW, if the owners manual is saying get the filter serviced, get it serviced, regardless of what a GM master mechanic says, because if it goes out, and it wasn't serviced, your warranty if still in effect is void.

 

[Jayce]

But there again... that would in essence be a non-pressured flush by doing a 100% refill... the thing that most people and these transmission shops are recommending to avoid... :/

I don't think it would hurt to have some of the old fluid in there either. I look at it like swapping water in a fish tank. To do a 100% water swap in one shot you would kill the fish. To do it in increments, no problem.

I'm dropping off the van tonight at Cottman (who would do the check and test drive for free) and we'll go from there. Hopefully it's good news...

EDIT - Owner's Manual.

EDIT II - It's noted (taken from above) as:

Change automatic transaxle fluid and
filter (severe service). See footnote (h). (50,000)

Change fluid and filter. Changing the filter is plain english. Change the fluid... as in... refill with what fluid you lose when changing the filter? Change it as in remove all of the fluid and refill 100% new stuff?

Maybe I do need to get a Haynes manual. This owner's manual sucks.

 

[C0RR0SIVE]

Well, in the haynes manuals that I have for my cars and trucks, they all say that the fluid change, is what comes out when dropping the pan and poping the older filter out, believe it or not, above that filter is usually 2-4 quarts of fluid that comes out, and it becomes messy. They also state that there is additional fluid in the torque converter, but does not express the need to empty that fluid.

I would honestly do what that shop says, but ask them nicely to change the fluid and filter, and ask them if they can use a brand that uses the Dexron name, several companies like Valvoline can use the GM Dexron name, because they actually meet all GM standards, and GM checks samples of that fluid to make sure they are staying in line with the Dexron standard. You will still have old fluid, but having half and half is better than having nothing but old, and nothing but new with the old filter in my opinon. I have changed the fluid in 6 transmissions at least twice per each one (I actually abuse these cars/trucks, and still no issues, but I change the fluid almost yearly also), and I have no issues yet in the 50-60k miles each one has had put on them since I started to take care of them.

BTW, some torque converters actually have a drain plug, not many, but some, that can be accessed while it's still inside the bell housing, that allows it to be drained, but I have never drained one, as I am unsure of how they would cope with turning for awhile with out fluid while it's being filled back up by the transmission pump. Pointless info really I think, just something I learned one day when pulling the engine on my car.


So yea, do the pan drop, filter replacement, and top off with fresh dexron 6, and in two or three years do it again if you feel like, that way you know you get basically, the majority of the old out of your transmission.

On a side note, Haynes lists a service schedule like your car booklet does, but on those it lists chapters you can read to get an understanding of the repair, it also has a large basic trouble shooting guide that you can read and understand if issues arise. Sometimes you can get lucky and they will list the average amount of time it takes a home mechanic to complete the job if all parts are available and all tools are there, though I seem to never get lucky on the time thing, might be the beer and cig breaks....

Along with getting that haynes manual (20 or 30 bucks usually) if can actually help you save money if you are confident with some tools and follow directions. My mothers car, 97 lincoln town car, has a bad MAF, Ford wanted $450 for it and to replace it. I found the location of it, took some MAF cleaner to it, and it's worked an extra year, but now it has to be replaced and I can find the part dirt cheap. I rebuilt a few engines my self, and my Haynes booklet has saved me a few grand compared to having a shop do the rebuilds.

One other thing about mechanic work, cars, and such, things that are done actually change, for instance, on 99-03ish grand am's, the intake manifolds on the engines had to be tightened to a certain amount of torque in a particular pattern, here is where an issue came up. It was fine to do that in the FACTORY, with brand new parts, but as the parts aged, GM started to get complaints. What happened is the aluminum became weak and would crack where bolted down following the method. GM revised that method on the parts, and all the new parts that are bought (these manifolds are $300 new alone) come with a paper, that list the new specs and how to install it, as manuals aren't updated to reflect those changes, but it's always wise to research the issues around forums tailored to your car.

Nearly EVERY auto maker has common issues, and things are revised for older cars over the years, just like Ford changing from an all plastic manifold to plastic and aluminum in the weak areas, the part had a sheet of paper with a different type of bolts taped to it, with new specs that the book didn't list, so I stuck that sheet of paper inside my book where that part of the repair was. Sorry for the old stories, just kinda bored, figured it might give ya some insight into the world of automotive repair, and why things can go to hell (wait, I can say that word?) at times in auto repairs.

 

[Jayce]

Good info sir. I appreciate the long response. I'm starting to wonder if the manual was actually referring to "change" as in the pan drop method. After all, most users probably wouldn't know the torque converter is holding a good chunk of the fluid, so perhaps that's why it's not even mentioned, therefore to the common user they may be "changing" the trans fluid but in actuality they're just doing a pan drop/top off which is an estimated half/half change overall. Maybe just me guessing though but I can't help but to wonder that.

That manual is something I should pick up. I like to do all of my own wrenching if at all possible. I have a few torque wrenches (ft and in lbs) and some nice tool sets that might help me out. It just sucks it's hitting me now when my stuff is boxed up for the move soon.

On a side note, the dealership called me back to ask if I wanted to bring my vehicle in to get the trans serviced. I explained to them my concern and they basically full well admitted that flushes don't really do damage but flushes can shed light on issues that weren't detectable yet, thereby confirming what I've been hearing on forums in regard to flushes sometimes not helping. I just wonder what they would do if I came in with 200k on the trans that's never been serviced. Would they still be happy to offer up a flush at that point too? Or would they recommend a pan drop at that point? Makes you wonder...

Ah well, at least I spent the time to read up more on it and learn more, so I'm happy. But with that, I'm still geared up tomorrow to have Cottman test things out and more than likely I'll have them do a pan drop, fluid top and filter change. Crossing fingers...

 

[C0RR0SIVE]

Most dealerships will flat out tell you to take a 200k mile car somewhere else if it was never serviced, if your lucky to get 200k with out a service. Most transmissions fail between 100k and 150k when not serviced at all. A lot of dealers will offer to do only a pan drop around here upto 100k with out the previous service.

Last shop I talked to, I asked them there opinion on a car that had 150k miles with no previous service, they said they would only do a rebuild and would refuse to even do a pan drop because it would pull up issues that are there, that haven't showed there ugly head because the old fluid is what's really holding it together at that point, along with the old gunk that has built up from the detergents finally being worn out and no longer are able to clean. It's not really the fluid wearing out, it's the detergents that get worn out these days, that's why pitch black motor oil can still be 100% fine, is due to detergents in the motor oil, if it's a good oil. I actually send samples off when I do my changes to see if a change was needed, and they are rarely needed in my cars due to being used on the highway for extended periods of time, but thats a whole different subject.

BTW, good luck man, I hope the best for ya, transmissions are normally more expensive in the end than an engine is honestly.