Auto Transmission flushing

ebutts

My daughter-in-law took her Ford van in to a quick
lube place for an oil change. They also suggested
having the transmission (160k miles) back flushed
without changing the filter. She did. After driving
approximately 50 miles and overnight the van
wouldn't operate correctly the next day. She called
a transmission shop and they told her not to drive
it, tow it in!

I have never heard of back-flushing a transmission
and not replacing the filter? Any comments on
this?

guitarzan

I have not heard of this either, but I'm not a mechanic.

Let us know what happens, and if the lube shop took responsibility.

guitarzan
Community Leader/Vans Conference

Sergeich

Which synthetic automatic transmission fluids are compatible with ATF+3? What is the best ATF+3 compatible ATF around?

bolton3

My 1993 Dodge Caravan SE has 168,000KM (105,000 miles) on the original transmission. I have read numerous sites which indicate severe problems with the 4 speed transmission. I recently went to a lube shop and asked for the transmission to be replaced using the 7176 ATF fluid, and a new filter. However, the lube shop was unable to remove the pan as the liquid gasket used at the factory would not release. The van has a tranny cooler, the fluid is cheery red and does not smell burn. My questions are:

1. Do I have the fluid and filter changed or should I leave it? It seems that changing it could cause problems. I had a small leak in the tranny cooler line and I replaced the fluid with ATF+3 (1 litre).

2. Is synthetic fluid better than the AFT+3 or 7176 type?

dhoff

First let me say that I have no direct experience with this. Having said that, I wouldn't use anything but 7176 fluid in a Chrysler transmission.

I don't know if you have seen this site. Check it out:

http://www.allpar.com/fix/trans.html

or:

http://www.allpar.com/

If you tranny has over 100,000 miles and the fluid is still clean, I don't know if I would change it. Do you know for sure if the fluid has ever been changed? I guess if you have owned it since new, you'd know. I have heard people say if you haven't changed ATF at or before 60,000 miles, don't bother changing it at all, but I have no idea how valid this advice is.

Dave

Sergeich

RedLineOil says that their C+ synthetic ATF is compatible with ATF+3. I think it is better but I did not put it in mine vehicle yet.

rea98d

With the possible exception of Saturns, the filter in most auto transmissions is nothing more than a metal screen designed to filter out the larger particles. It's not designed to work like an oil filter, because, quite frankly, it doesn't need to. With oil, you're getting all the soot and such from burning gasoline. In a transmission, all you have to worry about is the fluid, over time, breaking down from the extreme heat. Why Saturn puts oil-filter style filters on there transmissions is beyond me, but I have heard of people removing that instead of the oil filter in DIY oil changes (and even saturn techs doing that when they first start out!)

q45man

The 93 Caravan is one lucky guy. see :
http://www.thegrid.net/thedrivetrainpage/whtobuy.htm

The filter is necessary to remove the hardpart and failed clutch material from the fluid caused by overheating.

adrian01

We had a 92 Mazda 929 probably never had the fluid changed, the dealer said if it has never been changed don't change it ( had 92,000 at the time) so I did not change it. Two months later it quit, dealer wanted $3400 to fix it. There was another 929 in the same day, same problem. These new cars have very expensive transmissions and it is a good idea to take care of them. I bought a 96 Maxima and at 30K miles took it to a dealer to have the fluid changed, they dumped in 4 qts. of Pennzoil trans. fluid, Mercon 3 type and charged me $60.00. No filter to change, easier than an oil change. I started doing my own about every 15K($6.00 cost)... I now have a Y2K I30t and have already changed it, I also add one 10oz bottle of Lubeguard, really good stuff. The Nissan dealer also put in one can of BG tranny stuff. The trans. seems to shift better after the change and the additive treatment. (No I don't sell Lubeguard products, and I don't use Zainno!!)

wayn1

Amaoil just came out with their new ATF+4 tranny fluid for Chrys. products only. This is the only ATF anyone should use.

0patience

First,use only the RECOMMENDED ATF in your transmissions,Chrysler transmissions are real finicky about it.Second,clarification on the trans filters,not all of them are a screen type,GM likes to use a cloth filter type in the TH350 and 400,I have a spin on filter attachment on my pickup,because I tow with it.Contamination of the trans fluid is a big killer of transmissions.Backfushing only works if done properly,if it is not done properly,then it can ruin seals and valve bodies.The best thing you can do for your transmission is to do regular services on it.I recommend trans fluid changes at 30,000 miles.As for Amsoil,again,use a recommended ATF,and do regular services and save your money.

wayn1

Dirt is not the killer of trannies... heat is. Amsoil makes a special ATF just for Chrys. because they have had major problems with their trans. The use of Amsoil lowers the tranny temp to keep it from turning the oil into varnish. This stuff lasts for 100,000 miles. A little scary, as long as the ATF is nice and red then you will have no problems, I use it myself.

0patience

Dirt is not the killer?I'll agree that heat can create problems,but contamination from clutch fibers,dirt,metals and oil breakdown are the causes.Amsoil is snakeoil and I talked to Chrysler about it today,if it meets the manufacturer's specifications then it is acceptable to use.But they make no claim as to endorsing it.Their comment was to follow the recommended service schedule and use a transmission fluid that meets the manufacturer's specifications.

butch11

A couple of friends had major problems with their DC trannies after having one of those quick oil change places change their ATF using a "compatible" ATF as replacement fluid. One of these compatibles was a national brand synthetic-his tranny went in 5K.

Asked a local DC dealer about this-he showed me their ATF. They get it in big jugs and decant it to quart jugs. Their new ATF is reportedly backward compatible with all previous DC auto trannies.

I am also very suspicious of those people offering tranny flushes-no way in hell are they going to have the specific fluid for your vehicle unless they are a new car dealer.

These new trannies demand a specific ATF-if you want to be a pioneer-go right ahead and put in somebody's Snake Oil ATF-In about 5K miles be prepared to replace your tranny. Also changing tranny oil is easier on most vehicles than changing motor oil. Just drive it long enough to get the ATF hot and watch out for the hot oil-it is over 300 degrees F-will burn hell out of you.

brad45

Most trannies hold 12 quarts or more of fluid. Dropping the pan or pumping out through the dip stick tube only gets 4 to 6 quarts. That is why the back flushing method was developed. That and because, many auto manufs (including GM) have changed from removable cloth or metal screens to non removable metal screens. The back flush cleans these screens without removing the pan.

I don't know too much about the back flush process, but it sounds way to complex for the quick change oil guys to handle. I wouldn't trust them to install a pcv valve correctly.

New transmissions, according to a tranny tech I met, are not as sturdy as the old TH350's and C5's of yesteryear. What was steel is aluminum; aluminum is now brass, brass is now plastic and plastic is now pressed fiber. It is best to follow the manuf's recommendations for frequency and procedure and have a qualified tech. (tranny shop, good mechanic, or dealer) that you trust perform the work.

P.S. See my posts in Transmission Traumas to read more on my escapades. I didn't service mine when the book said to and I'm paying for it now.

butch11

My honda holds about 6 quarts-only get about 2.7 quarts when you drain it-therefore I change the ATF every 20K. Book says 90K-only do highway driving and at 70K got a check engine tranny code-fluid was a bit dark and had a slight burned smell-now change it at 20K.

lindeman1

I have a 1994 Mercury Villager with 53,000 miles. The transmission was serviced at 30,000 miles. I was considering a full flush, pan and screen cleaning and replacement with synthetic (Amsoil or Redline)but read in an "expert" transmission forum that synthetic fluids can cause shift quality problems. The "expert" claimed that his personal experience with synthetic fluids was not good and he didn't recommend them. Also, he was concerned that the new flushing machines might upset debris in the valve body creating more problems than they cure. He recommended simply dropping the pan, replacing the filter or screen, cleaning the pan and replacing the oil (about 1/3 to 1/2 of the total in most cases) with the factory-recommended ATF fluid. Now I'm not so sure about my original idea. I like the idea of synthetic fluid (use Mobil 1 in the engine) but don't want to compromise trans performance especially considering the cost. Maybe best to just get a "conventional" service?

div2

I fail to see how using a synthetic ATF can damage your transmission. That assumes that you use a synthetic ATF of the proper type for your transmission. I have used Mobil 1 Dexron II/III in my 1993 Pathfinder SE for @77,000 miles with no problems. I use a 50,000 mile fluid change interval. The "expert" may be correct about flushing a transmission which has not been serviced for a very long time. However, a transmission that has been serviced at reasonable intervals should not have an appreciable buildup of dirt or clutch debris. And a neglected transmission may well have so much grunge accumulated that a simple fluid and filter change will also cause problems. How much do you want to bet that the "expert" in question bad mouths flushing and synthetics because his shop doesn't have those services/products available?

lindeman1

I agree...the trans. in my Villager was clean as a whistle at the 30,000 service...red fluid, clean pan and almost no material on the magnet. Except for a slightly harsh occasional 1-2 upshift (more noticeable when accelerating slowly), the trans. shifts fine. I really enjoy the comfort and reliability of this van and would like to keep it for a long time. I already use Mobil 1 in the engine, replace filters at regular intervals, keep it clean and drive it sensibly (to make it last). I think I'll proceed with the flush and check into Mobil 1 Mercon. Thanks...

div2

Here is the link to the Mobil 1 ATF data: http://www.mobil.com/mobil1_racing/about/products/atf/index.html Looks like it will work in your transaxle.

oilcan2

Have been using Amsoil trans fluid for about
10 years,I change it at 3 yr. intervals.this oil
does not varnish or break down like conventional
trans fluids.The "manufactuers" said the same
things about mobil 1 and other syn eng oils when
they first came out.Look how many GM cars are
shipped with syn oil now ! The bottom line is
that syn oils extend the life of the transmission.
Let's face it,the car makers do not want these
vehicles to last forever.

hoofer

First, you can see more details of my experience with Chrysler transaxles and silicon contamination at topic #970 for Vans.

I am getting to be an expert on DC transmissions whether I like it or not.

I have a 1996 and a 2000 GC with 3.3L.

The powerflush is not really a backflush. They just connect the transmission to a reservior of virgin fluid and let the internal transmission pump draw it in, run it through and then into a waste tank. It is the only way to get near total fluid replacement.

Just replacing the 5 quarts or so that goes with a traditional drop-the-pan filter service is like taking a shower and putting your dirty clothes back on.

I have spectrographic oil analysis to show the difference. See topic #970 for the skinny.

best of luck

bja104

I have a 1998 Ford Expedition w/ E4OD automatic transmission. Regarding ATF changes, the manual says "no regularly scheduled interval" for changing the fluid. Does this mean I don't have to change the fluid (sounds fishy to me)? I change it whenever I want to? Anybody know what this means?

Thanks.

spokane

Bja104, for light-duty service, the manufacturers now specify that the ATF never needs to be changed on some vehicles. I suppose this looks good as one element of the "low maintenance" which is now being touted for some cars. However, it's surely good insurance to change at intervals of 30K miles for normal service. More often if you frequently encounter conditions of high temperature, heavy loads, or high speed. As "hoofer" and others have indicated, flushing the torque converter as well as changing the fluid in the sump will provide additional assurance of long transmission life.

moram2

hOW TO CHANGE TRANS FLUID ON A 96 PONTIC SUNFIRER
2.2.
THERES NO DIP STICK ON THIS ENGINE,SO HOW DO i CHANGE IT

div2

Many of the new automatics have a drain plug and a filler plug; you drain the fluid(then pull the sump and clean/replace the filter if you want), and add the new fluid up to the level of the fill hole. Be sure you can remove the filler plug FIRST. More than one mechanic has been caught out by draining the fluid then finding that the filler plug is stuck tight...

bblaha

If you remove the pan to replace/clean the filter, REPLACE THE GASKET...

div2

Good point; although every transmission filter I've purchased came with a new pan gasket, I suppose you shouldn't assume anything these days. Case in point: the GM tranny in my wife's 3er has two pans and the replacement instructions specifically state NOT to tighten the bolts in the usual criss-cross pattern- you tighten them in-line as it were.

hoofer

I use Schaeffer Manufacturing for my spectrographic oil analysis: www.schaefferoil.com

They cost $7.50 plus tax per test (includes test bottle, business reply mail bottle).

If you are comparable (could not find pricing information at your website) I would like to send samples to both you and Schaeffer for compare and contrast.

I am doing battle with silicon contamination in my Dodge Grand Caravan engines and transmissions.

I have a 1996 and a 2000. I have high silicon in both the engine and transmission of the 2000 and in the transmission of the 1996. Using Texaco Havoline 10W-30 in the engine and ATF+3 (Type 7176) in the tranny - Chrysler house brand in the 2000 and Quaker State in the 1996.

Wear metals have dropped to normal after multiple engine oil changes and transmission powerflushes, but silicon continues to persist.

Have also tested transmission samples from co-worker's 2000 GC and neighbor's 1998 GC - both of those also have high silicon.

All have 3.3L engine.

Any insight you might have on this problem would be appreciated.

You can contact me directly at hooferpm@cs.com

best of luck

oilcan2

Have you considered a amsoil by-pass filter for the engine will filter down to below one micron.

0patience

What Amsoil does not tell you, is that on a "by-pass" filter, it is designed so that over a certain PSI the unit by-passes the filter cartridge.So if the oil pressure spikes (which it does constantly) it pushes past the by-pass relief and past the filter. Almost all filter heads with a relief or by-pass on them are designed this way. If they weren't then it would blow gaskets,seals and in some cases, hoses.
So the one micron is a stretch of the truth,the element may indeed (not likely) filter to 1 micron,but I can assure you that more than 1 micron is making it to the engine. I don't see how they can make that claim when an expensive high filtration,high pressure hydraulic filter only filters to 5 microns. I'm not saying it is a bad thing, I'm just saying that the numbers they throw around are misleading.

oilcan2

I don't think you know what a amsoil by-pass
filter is so here goes.
It is a seperate filter system designed to be
used in conjunction with your spin-on filter.
It consists of a filter mounting bracket,a spin
on filter(made by amsoil,3 sizes from about 1 to
3 qts.and filters to the one micron size)and hoses
to mount.you tap in to a oil pressure source
usually a tee at the oil sending unit,this goes
into the filter housing,another hose goes to a
non-pressure point to return the oil,usually the
oil pan or valve cover.I have used these and seen
them on many dif. cars with no problems.

0patience

I didn't say that there would be problems, I said that the micron rating is BS, the filter cartridges are built with reliefs in them and when a hydraulic system (which an oil system is) spikes (which they all do constantly) it goes past the relief. Adding another filter "in line" with the current one or using a remote mounted dual filter assembly is the best way to utilize the filters. Running from another port and dumping into the pan is defeating your purpose of having 2 filters. As for not knowing about filters, I spend 20% of my work time contending with oil analysis, filter break downs and lubricating specs. If you wish to continue this, tell you what,either find a more suitable area on this site for it(synthetic oil one or something) or click on my name,there is a site listed in my profile,go to that site and go to the mechanics forum or the heavy truck forum and make a post. I'll be there.

hoofer

I guess Schaeffer's $7.50/test beats his price.

best of luck

armtdm

You need to remember two things if you are getting high silicon (dirt) readings on oil analysis. First, the analysis can not differentiate between dirt and silicon used in seals. Most new engines use silicon seals and my expereince is that it takes about 20,000 miles for the seals to stop putting silicon into the oil being analyzed. Second, most oils contain silicon as a part of their make up. Some up to 15ppm. So if your reading of silicon is 40 or 50ppm it may be very good but the analyst firm does not know how much was in the oil to start with and how much is from the seals. For the oil, you could send them a new never used sample to get the chemical analysis!

johndope

Precision tune recommended my girlfriend flush her chevy celebrity's trans. The car has 52,000 miles on it and I assume that the trans has not been flushed in its lifetime. Should she follow the mech's advice and flush it?

pinecrestjim

If the owner's manual recommends changing the fluid at regular intervals, then do it.

My Buick dealership did my '91 LeSabre using the backflush method ($79.00) at ~110K, the second time the oil had been changed. If a dealership is recommending this method, it should be OK. They'd have to take the responsibility of damage if something went afoul.

Jim M.

edwardh1

In a recent issue of Consumer's Reports, the ratings for oil changes by readers, put the Quick Lube/Jiffy Lube type places all at the bottom (worst) , after all the dealers.

morg7

At the beginning of this year I took my 97 Sonata in for a 30000 mile service at 40000 miles. I bypassed the dealer and took it to a service shop. Of course a tranny service is included. A couple of months later I took the car in for an oil change and the mechanic said that my transmission needed to be serviced. He showed me my trans fluid on a white card and it was brown. Now a friend of mine told me that it was just old fluid from the torque converter that was mixed in with new fluid. Is this correct? Or was the mechanic right and that service shop never touched my trans. fluid? I would appreciate some input. Thanks.

copytech

It depends on what kind of "service" was performed. Since most foreign autos have a screen and a drain plug on the tranny, a simple drain-and-fill service is performed in the 30k, and 60k etc. services. A drain and fill usually is only about 30-40% of the fluid, if that. New fluid will be mixed with old fluid. But there is no way to say it's "torque converter" fluid. It's all part of your tranny fluid. A d+f is better than nothing, but you'll need to do like 3 or 4 drain and fill services to dilute the fluid to an almost new status. The best way is to take it to a shop tnat has a T-TECH machine and to a full fluid and tranny cooler flush. A quicky lube place is so-so as long as the tech has done quite a few of them and is familiar with the car and the machine and as long as they use the proper fluid for your vehicle. Once they hook the t-tech lines to the in and out of the cooler, the machine does all the work. I'd take it to an inde with the machine. At 4 grand, the machines aren't cheap, but some shops have them. Keeping the fluid up can make your tranny last a long time. Trannys nowdays are designed to run MUCH HOTTER than old ones, so keep the fluid up. The electrical components benefit as much as the clutches and the valve bodies. Good luck.

tinindiana

I have a 1992 accord and have had the at fluid changed at the dealership. I have always done normal oil changes myself and want to do the AT fluid also. I have the chiltons manual, and it does not say anything about an AT fluid "filter" that needs to be changed. Does my car have a filter or do I just drain the old AT fluid and replace? Any input is greatly appreciated!

pat455

You might also want to post this question in our active Honda Accord Problems (Topic #1398).

Town Hall is fortunate to have an experienced Honda tech hanging out in that topic who has been very helpful to our community members with Honda maintenance and repair questions.

Pat
Community Leader/Maintenance & Repair Conference