I Changed my transmission Fluid

[Manny]

Hi everybody. I changed my transmission fluid today, as I do every two years (roughly every 24K). Today I found this in the trans pan:

(No - not the magnet I know that should be there - the particles)

Does that spell approaching trouble?

[adallak]

Hi everybody. I changed my transmission fluid today, as I do every two years (roughly every 24K). Today I found this in the trans pan:

(No - not the magnet I know that should be there - the particles)

Does that spell approaching trouble?

The debris should not be there. Besides, the liquid looks brownish, which is not good either. Did it smell burnt?

[JimD]

I changed my transmission fluid today, as I do every two years (roughly every 24K).

My knee jerk is to ask "why would you do that; do you also change engine oil & filter every 3,000 miles or 3 months?"

But I won't ask the above questions.

Does that spell approaching trouble?

To answer your question: No.

From my experience driven point of view, the fluid maintenance schedule in the Owner's Manual is the most cost effective approach for 99% of drivers. If you feel you fall in the other 1% then do what you have to do.

A few words about my 12+ years of Northstar / 4T80-E transmission fluid experience. My '98 model currently shows more than 197,700 miles; the transmission fluid was 100% replaced (without dropping the pan) more than six years ago @ 124,800 miles.

I have no idea what sort of crud might lurk in the bottom of my transmission pan. And I don't care. Because whatever crud lies in there will remain there until the vehicle is crushed and melted.

It's your car and your anxiety. Happy motoring.

[Manny]

Jim

You ask why do I change it that often? Because like any fluid, hydrolic fluid has a usable service life. Oil? - I use the oil life indicator.

Adallak

It did look darker than it should, but it didn't smell burnt.

[stsevillests]

Looks like normal wear to me. My 95 Seville has 167,000 on it. Changed my fluid and scavenger filters not long ago and it looked about the same, other than some orange rubbery stuff, like gasket sealer, and some insulation looking stuff that i was told was wear of the bands. Transmission still ok.

Not sure what the service manual calls for but 2 years/24K miles seems like overkill to me.

[Cadillac Jim]

All automatic transmissions oil pans have a few metal particles in them. Showing these to a customer to sell a unnecessary transmission rebuild is one thing that was cited in an FTC class action against a chain some years ago, and a consent decree was issued to prevent this and other "deceptive marketing practices."

[adallak]

Jim

You ask why do I change it that often? Because like any fluid, hydrolic fluid has a usable service life. Oil? - I use the oil life indicator.

Adallak

It did look darker than it should, but it didn't smell burnt.

I am only coming from my experience which is limited to owning one Cadillac for ten years. Those members who have much more extensive experience may have a better idea. As for me, I have changed the filter and fluid on my 1991 Seville two times: at 100,000 miles and 130,000 miles. Both times there was only a thin layer of metal dust in the pan, nothing which would look like the debris in your pan. The fluid was discolored but did not smell burnt. It was the same pink just much paler. The transmission was perfect till the day I parted with the car at 175,000 miles.

Changing ATF every two years might be an overkill, BUT if the fluid gets brownish, you better change it even if it does not smell burnt yet. If a transmission have a tendency to change the color of ATF (no just the intensity of original red), I personally, would watch it closely and change the fluid and filter every time I believe it is necessary and hope for the best.

[Cadillac Jim]

The transmission will have more particles in the pan the first time it is serviced than thereafter because that first time, you have the products of break-in wear as well as normal wear.

I use the smell as an indicator of the health of oil and ATF. A better test would be an analysis of the fluid like that done by Blackstone Labs for engine oil. Their web site is

http://www.blackstone-labs.com/

I don't know if they do ATF analysis or not.

There is another company that I turned up in my collection of links, Dyson Analysis, but I don't see anyhthing on their site that advertises ATF expertise either. Their web site is

http://www.dysonanalysis.com/

I would call and ask if they do ATF analysis and whether they can interpret it. Without some experience with analysis results from new, mid-life, and old transmissions of the same general type as yours, and also some results from bad or failing transmissions, analysis is limited to educated guesses rather than noting similarities to previously observed results. So, ask about their experience with ATF analysis and interpretation.

[winterset]

The transmission will have more particles in the pan the first time it is serviced than thereafter because that first time, you have the products of break-in wear as well as normal wear.

I use the smell as an indicator of the health of oil and ATF. A better test would be an analysis of the fluid like that done by Blackstone Labs for engine oil. Their web site is

http://www.blackstone-labs.com/

I don't know if they do ATF analysis or not.

There is another company that I turned up in my collection of links, Dyson Analysis, but I don't see anyhthing on their site that advertises ATF expertise either. Their web site is

http://www.dysonanalysis.com/

I would call and ask if they do ATF analysis and whether they can interpret it. Without some experience with analysis results from new, mid-life, and old transmissions of the same general type as yours, and also some results from bad or failing transmissions, analysis is limited to educated guesses rather than noting similarities to previously observed results. So, ask about their experience with ATF analysis and interpretation.

I believe the transmission fluid exists in a PH harmony with the inner seals & non-metalic components in the unit. Once the fluid is changed, a revolt occurs internally, and all sorts of chemical reactions begin. Everytime I hear someone changing their fluid, they have issues. I believe even the transmission fluid has a life monitor- & until I get a message to change it, it'll stay there.

I am waiting for transmission fluid for "High Mileage" cars that does NOT have added cleaning agents, but instead none at all. Not sure what people have fascinations about keeping things internal so clean. where does the dirt come from in a tranny afterall.

[Cadillac Jim]

The Northstar transmission fluid life algorithm is pretty interesting. It stays at 0% life until and unless the transmission overheats, so far as I know. The owner's manual says not to bother changing it unless you use the car for towing, and then to do it at 80,000 miles, if my memory serves.

The transmission is not sealed. There is a vent, and the transmission breathes as it warms and cools. The debris comes from clutch and band wear, gear wear, etc., all normal things. That's why the oil pickup has a screen and filter.

Many years ago, 2,000 mile oil changes and 24,000 mile transmission service was the norm. Nowadays it's dealer's choice. I change my oil when the OLM hits 50%, never letting it go below 40%, and I never use anything except synthetic. I use 5W-30 because the dealer has recommended it for my car since about 2000 and I believe that it gives just a tiny bit better performance. What you do is your decision; you can be assured that if you follow the recommendations in your owner's manual or better your car is well cared for.

If you haven't changed your transmission fluid since 2006, you should get your transmission flushed and Dexron VI put in, particularly if you plan to drive the car several more years with the same transmission. Clutch life and shifting performance of any Dexron-compatible transmission is dramatically improved with Dexron VI over its predecessor, Dexron III, and GM no longer supports manufacture or use of Dexron III or earlier ATF formulations. If you pull the pan and clean it out, do that first, then flush it to completely change out the fluid.

[JimD]

One more time, from the top:

Flushing is for commodes.

Flushing transmissions or cooling systems is not a GM recommended procedure.

Flushing is potentially harmful to the owner and a source of incremental income for service departments and Jiffy Lubes.

[stsevillests]

I was always told to never 'flush' a transmission that never had regular service done or that will lead to problems even if you didn't have any in the first place. An older 'worn' transmission needs some dirt and grit to make things connect. I have heard of people flushing the transmission and the car wouldn't even drive off the lift after doing it. Maybe not true but I researched a lot before deciding to just drop the pan and refill with new fluid.

Drop the pan, clean it, change filter, Northstar has the 'hidden plug inside' to drain more fluid out. Refill.

Also someone recommended to me to add a bottle of Lucas transmission fix when I changed mine. Maybe it is snake oil, bottle says reconditions seals etc. but it seemed to me it made transmission a lot smoother. Maybe it's in my head or the fact of new fluid being added that made the difference.

If adding the Lucas replace that amount of fluid. Do not over fill the transmission.

When I did mine it took about 7.5 quarts including the Lucas.

[JimD]

....When I did mine it took about 7.5 quarts including the Lucas.

It is possible to completely change the fluid in a 4T80-E transmission (11+ quarts) with dropping the pan, without transmission fluid dripping off your elbows, and without even getting your fingernails dirty.

[rockfangd]

That debris looks like torque convertor and band clutc material. Nothing more than normal.

I am very happy to say that my 96 Deville is approaching 20000 mmiles and still shifts like new, my fluid is still pink, and I have 0 intentions on changing it.

On my previous cars I have changed the fluid and filter around 100000 miles and maintained there on out, but On a cadillac it is not very necessary unless there has been a failure or major malfunction

[Cadillac Jim]

My Eldorado has almost 150,000 miles on it. I've had the transmission serviced every 30,000 miles or so, always at a dealer with a good service department. Since about 2000, that service has amounted to a transmission flush. After notices here such as the one by JimD on this topic, I quizzed the local dealer about that in some detail. They told me that this was the GM recommended transmission service for a transmission that did not have driveability issues or known problems. I have a lead foot, use the gear selector for engine braking occasionally and to get firmer upshifts and keep the engine in a lower gear in demanding situations, and generally do not baby anything. The transmission shifts like new. No leaks.

The time is nearing for another transmission service, on the basis of my personal 30,000 mile schedule. I plan to ask my mechanic about what he would do and decide whether or not to take it to the dealer or to let him do it.

The transmission flushing procedure, as I understand it, amounts to hooking a machine to the transmission cooler tank in the radiator and flushing that out, then doing a similar thing with the transmission itself, feeding new transmission fluid in the cooler return line while disposing of the old fluid being pumped out of the transmission through the cooler output line, while the car is running and in gear. Some processes use a high concentration of some kind of seal softener or cleaner at first, some simply use enough Dexron VI to make sure that nearly all the old fluid is out of the transmission. No GM-approved process is going to use additives or concentrations of additives that will harm a transmission. I don't see how this can cause a problem.

I've seen posts here that say that if a flushing machine has been used on a failing transmission, it will have debris in it that may not be cleaned out. If the flushing process uses fresh, new Dexron VI, with our without additives in part of the process, I don't see how this will carry debris from previous usage into the next transmission because no fluid -- or debris -- that exits a transmission ever enters another one.

I don't see how flushing a transmission is harder on it than changing the fluid. Changing the fluid, including draining the torque converter with the second plug, gets about 80% of the old fluid out, while the flushing process essentially does the same thing more than once, so that the process gets 95%+ of the old fluid out. If the transmission is in good shape and all you are trying to do is to refresh the anti-oxidation and ZDDP additives, these processes should be equivalent insofar as the health of the transmission is concerned. It's just that it is simpler and may be cheaper not to drop the pan. And, if you have an old car with Dexron III in it, you are well-advised to flush it out 95%+ and get Dexron VI in it.

I think that dropping the pan and changing the filter and cleaning out the pan is a very good idea, particularly on the first transmission service. On the other hand, the owner's manual says not to bother with any transmission service unless you use the car for towing, and I would never use my Cadillac for towing anything; I can pick up the phone and buy a beater pickup that does that better for $1,500, service it and shine it up afterward and make money on it when I sold it. I've seen lots of Cadillac owners here that drive their cars 200,000 miles without servicing their transmissions. So, if GM says that I never need to drop the pan, I can believe that it's not that bad an idea for a Cadillac. The idea of servicing it every 30,000 miles is admittedly a holdover from older cars.

[coolnesss]

I live in the Hollywood Hills, and drive a fair amount up fairly steep grades, then onto Mulholland Drive where aggressive driving causes the car to up and down-shift constantly.

The neighbors here have a transmission life of about 50-70,000 miles - except those of us who change fluid every 20 or 30,000 miles, and the transmissions then have a normal service life.

The factory rules don't apply when you have harsh operating conditions such as these, and experience has borne this out for the 40 years I've been paying attention to cars around here.

[the gold2]

Hi, I'm a new member and owner of a 1992 Eldorado. It has 45K miles. I have the original service records. It has had one tranny service but I'm not sure whether it was the 'flush'.

The owner's manul recommends a fluid/filter change every 100K miles unless it is driven under "severe" conditions, like alot of hilly grades and I assume alot of non-freeway driving.

I used to own a 1984 Dodge Daytona turbo coupe. Once I drove into a transmission shop when the car had about 75K miles on it and inquired about a tranny service. The mechanic told me to "never crack that tranny open" he said that the tranny was a really good one (model) and just leave it. He implied that servicing would do more harm than good. He never asked about driving habits.

Knowing that car manufacturers rely on service centers for recurring revenue, certain statistics and 'scare advisories' are designed to motivate periodic service $$.

In the case of the transmission, heck, if the manufacturer states a 100K service period, then perhaps that is best. If the fluid looks OK on the dip stick....

I own other cars (foreign) that do require 30K service otherwise for sure you are asking for failures down the line ( as per experience and particular forum anecdotes).

The point is that GM apparently made some trannies that were excellent.

In my '92 Eldorado's case, I was planning on getting opinions about this vintage tranny. Your post is timely for me. I hope to just let the existing tranny state ride for many years to 100K miles since it is only at 45K miles and the service was done about 10K miles ago. The past owners did City and Highway driving.

I hope others can opine with some background info.

THX.

[Ranger]

I think if a fluid exchange (aka flush) is done correctly, it can be OK. A "back" flush is another story.

As far as Lucas "reconditioning" seals, does anyone know exactly what that means? How do you "recondition" a seal?

[billytheshoe]

Dex III will go 100,000mi. Dex 6 will go for eternity. shorten those intervals more than 50% and you are wasting oil under normal use. Towing or very unusual hard use will be the only factors that may alter the transmission oil life. The traction control & other systems working properly prevent the ability to really hurt something in the motor & driveline & overheating.