As I type this, I can feel the sweat building on my brow as I have read some of the posts regarding the DON'TS of changing the transmission fluid. I only wish I had read this a month ago. I have always had my car serviced by a Cadillac Dealer (a reputable one as I have always been taken good care of) and as such I put faith in what the Service Advisor tells me as I have known him for some time.

The car has 69000 miles on it and I figured since it's 8 years old, why not change the fluid. I had asked for it to be done and while I had initially asked them to drop the pan etc. I was eventually persuaded into doing the flush. The sell was that I was told it was the recommended procedure. Price had nothing to do with it since they would have charged me the same.

The car runs and drives fine like it always has but now I'm starting to get that uneasy feeling that I may have done something that I shouldn't have. Have I????? Should I go and have it changed again the right way???

Thanks guys.

I have heard unsubstantiated rumors that flushing the tranny in essence swirls around the dirt/metal shavings that are in there, and can cause tranny failure in quick order... I suppose it depends on how they did it. If they hooked into the tranny cooler, I don't think it would do much damage... I don't know. I always think you should change the filter at least - that's like changing your oil and leaving the filter!

I hear you. The thing is I asked the same question and was informed that the filter is a permanantly installed component. In other words, it's not removed and replaced. It's simply cleaned. Like I said, that car drives as well as it always has and I do trust my guy down there, but I'd be lying if after reading some of these other posts that it didn't concern me. I'm only curious to know if whether or not I decided to have them drain it the old fashioned way, would it prevent any potential problems from developing or has the damage already been done? I'm hoping I'm overreacting.....

Thanks again

Interesting... I didn't know that. I wouldn't worry about it then... Sure it's always better to clean the pan of metal shavings and what not, but it's also a pain and messy. Just hold off until you reach 150k ;)

I hear you. The thing is I asked the same question and was informed that the filter is a permanantly installed component. In other words, it's not removed and replaced. It's simply cleaned. Like I said, that car drives as well as it always has and I do trust my guy down there, but I'd be lying if after reading some of these other posts that it didn't concern me. I'm only curious to know if whether or not I decided to have them drain it the old fashioned way, would it prevent any potential problems from developing or has the damage already been done? I'm hoping I'm overreacting.....

Thanks again

You have good reason to feel nauseous....there are many cases of perfectly good transmissions being damged by transmission flushes....

If it were mine, I would have the trans bottom pan dropped, the pickup screens cleaned as well as the pan, the side cover oil drained (there is a hidden drain plug for the side cover inside the bottom pan) and the trans refilled with fresh fluid. You have no idea what went into the trans nor what kind of fluid it was. Have it changed to minimize the chance of the flush causing you any problems.

The actual "filter" in the 4T80E trans is inside the side cover so it is not commonly serviced unless the trans is out of the car for some other reason. Just draining the side cover is sufficient but the bottom pan has to be removed to do this (to access the side cover drain plug). The 4T80E trans operates as a dry sump unit with the trans scavenge pump pulling the oil from the bottom pan to the side cover where it is stored to be picked up by the main pump. The bulk of the fluid is inside the side cover so the side cover MUST be drained with the "hidden" drain plug to effect an oil change.

Thanks for your responses fellas. Bbobynski, have I passed a point of no return with this or do I still have an oppotunity to fix it like it never happened??? My second question then is why would my guy be so adamant about having it done this way versus the other? As for what actually went into the trans, I agree that your guess is as good as mine and I know that the receipt says it was new fluid but of course the recipt can say anything they type I guess. I should have stood my ground on that one.

I was going to have an ATX flush done on my ETC (45,000 mi), until I read this thread. I will be taking bbobynski's advice. But I do have one question. What type of fluid should be used? Maybe Mobil 1 synthetic ATF?

Willglueit: Do me a favor if you could. When you do have the fluid changed, ask them what procedure they recommend and why. Im curious to know if they will say the same thing. I assume you're taking it to a Cadillac Dealer.

Thank again

J.A.O......... Many, many and yet more will say to flush it. Don't!

WillGlueIt........I am a Mobil 1 beleiver. $6.00 a qt. and I think worth every penny. Others will disagree so I'll agree to disagree right now. But yes Mobil 1 does meet the Dexron III requirment of your 98 ETC.

So what's the verdict?? I've driven only about 1000 miles since this was done. If I go back and demand that they drain it, will there be any benefit or have I already sealed the fate??? By the way, how many have actually had a problem develop later on and what happened???

So what's the verdict?? I've driven only about 1000 miles since this was done.

Well, I think bbobynski said it already, and I agree. Drop the pan and get what debris and fluid you can out of there. Has it already caused any damage, hard to say. The longer it drives OK the more clear the answer will be. That being said, as far as I'm concerned, if it fails in 100K I would always question if was caused by that flush.


If I go back and demand that they drain it, will there be any benefit or have I already sealed the fate???

Yes, if drop the pan and change it you will lessen the chance of future problems. Will it make it like it never happened, no. All you can do at this point is change it the right way and forget about it. That is all you can do.


By the way, how many have actually had a problem develop later on and what happened???

You can search this forum for posts on that. I have read many but haven't book marked them. Try "flush" and "transmission" for keywords. I have never had it happen, of course I have never flushed and change fluid often. What happens is debris, either from your car or from the flush machine, gets introduced and lodges in places it shouldn't be and obstructs the function of that particular device. The malfunction could be one or several of many. But usually has to do with more delicate items such as the TCC and shift control solenoids. One way or another, not good, as the trans has to come out to be fixed.

J.A.O, I am going to do it my self. I like to do all my own vehicle maintenance, except for tire balancing and alignments.

Lawrence, I have used Mobil 1 ATF in several cars. All of them seemed to love it. A 88 Lincoln Continental, a 95 Ford Probe and a 95 Bonneville SE, I have faith in the stuff. I bucket flushed the Probe, that was two years ago and it's doing great. With the Lincoln and Bonneville, I changed the fluid and filters twice in two months. The Mobile 1 really made a difference in the Bonneville, it shifted much better in the summer heat than it did before the Mobile 1.

I love the stuff. I run it in every mechanical thing I have. Air compressor, lawn mowers, auto engine, trans, diff. If it holds oil and M1 makes it, it in there. I have had it actually FIX many, many and many more problems I have had over the years. I could fill a book on how many issues it has solved for me. Here is the first one.

I first got on to synthetics when I was a kid. My main ride, a Yamaha AT-125, was my second motor cycle. Love it as I may, it had it's problems. It was a street/trail bike. Well I loved to race it. The throttle had two posistions, ON & OFF. It was all I had so I made due with it. The biggest two problems I had with it was the horribly notchy shifting and clutch fade. These were inherent problems with the bike mind you, normal. I always maitained it meticulously. Gear box fluid was changed every 2 or 3 rides with off the shelf motor oil (every ride if the clutch faded on me). Top end was taken down and cleaned every 30 hrs, etc, etc. The only things that ever slowed me down was the shifting and clutch fade. Missed shifts sucked and when the clutch would fade I had to practically stop for about and hour for it to cool down.

I first tried synthetic 2 stroke oil (Klotz). I immediately noticed the bike was faster and ran better (could have been the jetting). When I took the top end down for cleaning notice far less carbon. Nice!

So, I though I'd try some new gear oil. This was a big leap for me at the time. This stuff was expensive and money was short. I needed to see results. This bike used reg automotive motor oil for the gearbox, so I got some synthetic. Can't remember now what brand. WOW!, what a difference. The bike was much faster and the shifting went from notchy and ackward to extremely positve. I could even pull off WOT clucthless shifts, which was immpossible before. I thought, man this a great, now I see how those other guys go so fast. So on to my next test. I took the bike down into the tightest, thickest, most muddy place I could could find. WOW! again. I could actually get through this stuff with out any sign of clutch fade. Now, I rode through as a always had, which was carefully (or the clutch would fade). So I decide to try again and just use the clutch as it should be used. I got down into that stuff and just ABUSED that clutch. I mean just WOT and only the clutch to adjust speed. The clutch on that bike NEVER faded again. It impressed me then at 15 yrs old and still today, some 30 yrs later.

When I started driving I looked for synthetic but the only one out there was Amsoil and it was not API certified so I didn't use it. it was some years later that I started using Mobil 1. That was back when M1 was black as tar right from the bottle. I beleive it had moly in it then. Been using it ever since. I have owned many cars and the differences I see in them are as I change them over to M1. When I buy a car, most always used, the first things on the list are M1 all the way around. Sometimes it takes me a couple of months to get it all, but I do it. Always notice a huge difference in every aspect. In general my experinces are that the engine oil flows smoother at start-up (especially in cold wheather) and the motor runs better, smoother and revs free'r. The auto trans and tranfer case shifts smoother, pulls harder, is much less "bulky"( especially when cold) and is much more quiet. The manual trans always shift better. And even the diff runs smoother, cooler, quieter (and quiter says alot to me mechaniclly). Collectively I ALWAYS notice much improved performane.

Many OEM's are specifing M1 motor oil (GM, Porche, BMW, etc., with more signing on all the time) and I know GM is using synthetic it as factory fill in their newer differentials and as a recommended upgrade to others. Mercury marine requires synthetic in their Opti-Max and High-Perf models as well as their gear boxes, both as factory fill and as an upgrade to the ones that didn't originally spec it. Even my air compressor requires (by the manual) using M1. I have seen dyno tests showing HP improvements with M1 with many drag racers are seeing improved ET's. Modest, yes, but improvements. M1 does not break down and leave deposits in you engine. While most newer oils don't do it to the extent that they used too, they do it by adding better detergents. M1 in inherently cleaner so it doesn't require the use of so much detergent. And detergents aren't good for an engine either.

Well, as I said, I could fill a book with specific personal instances if I get into all the improvements I have seen in the cars. Maybe not as impressive to me as that first (and many others bikes, including a GSX-R750) but very impressive to say the least. But I'll stop right here as this could go on for days.

I have never seen any problems with M1 that others have posted about. Oil leaks and such. Never, not one. As a side note, I now go to Wal-mart for oil changes ($27.88). Thats cheaper than the dino stuff at some of the quick change places. The mgr there said M1 changes are accounting for over 10% of his oil changes, and going up all the time. Dosen't mean much but I was surprised it was that high knowing how cheap (not necessarily bad) most people are when it comes to these things.

With the Lincoln and Bonneville, I changed the fluid and filters twice in two months. The Mobile 1 really made a difference in the Bonneville, it shifted much better in the summer heat than it did before the Mobile 1.

Yes, on the Bonneville if you want to get ALL M1 in there you need to change several times using the "blotting" technique. But I thought all the Ford's had a converter drain plug? Did they do away with them?

I love the stuff. I run it in every mechanical thing I have. Air compressor, lawn mowers, auto engine, trans, diff. If it holds oil and M1 makes it, it in there. I have had it actually FIX many, many and many more problems I have had over the years. I could fill a book on how many issues it has solved for me. Here is the first one.

I first got on to synthetics when I was a kid. My main ride, a Yamaha AT-125, was my second motor cycle. Love it as I may, it had it's problems. It was a street/trail bike. Well I loved to race it. The throttle had two posistions, ON & OFF. It was all I had so I made due with it. The biggest two problems I had with it was the horribly notchy shifting and clutch fade. These were inherent problems with the bike mind you, normal. I always maitained it meticulously. Gear box fluid was changed every 2 or 3 rides with off the shelf motor oil (every ride if the clutch faded on me). Top end was taken down and cleaned every 30 hrs, etc, etc. The only things that ever slowed me down was the shifting and clutch fade. Missed shifts sucked and when the clutch would fade I had to practically stop for about and hour for it to cool down.

I first tried synthetic 2 stroke oil (Klotz). I immediately noticed the bike was faster and ran better (could have been the jetting). When I took the top end down for cleaning notice far less carbon. Nice!

So, I though I'd try some new gear oil. This was a big leap for me at the time. This stuff was expensive and money was short. I needed to see results. This bike used reg automotive motor oil for the gearbox, so I got some synthetic. Can't remember now what brand. WOW!, what a difference. The bike was much faster and the shifting went from notchy and ackward to extremely positve. I could even pull off WOT clucthless shifts, which was immpossible before. I thought, man this a great, now I see how those other guys go so fast. So on to my next test. I took the bike down into the tightest, thickest, most muddy place I could could find. WOW! again. I could actually get through this stuff with out any sign of clutch fade. Now, I rode through as a always had, which was carefully (or the clutch would fade). So I decide to try again and just use the clutch as it should be used. I got down into that stuff and just ABUSED that clutch. I mean just WOT and only the clutch to adjust speed. The clutch on that bike NEVER faded again. It impressed me then at 15 yrs old and still today, some 30 yrs later.

When I started driving I looked for synthetic but the only one out there was Amsoil and it was not API certified so I didn't use it. it was some years later that I started using Mobil 1. That was back when M1 was black as tar right from the bottle. I beleive it had moly in it then. Been using it ever since. I have owned many cars and the differences I see in them are as I change them over to M1. When I buy a car, most always used, the first things on the list are M1 all the way around. Sometimes it takes me a couple of months to get it all, but I do it. Always notice a huge difference in every aspect. In general my experinces are that the engine oil flows smoother at start-up (especially in cold wheather) and the motor runs better, smoother and revs free'r. The auto trans and tranfer case shifts smoother, pulls harder, is much less "bulky"( especially when cold) and is much more quiet. The manual trans always shift better. And even the diff runs smoother, cooler, quieter (and quiter says alot to me mechaniclly). Collectively I ALWAYS notice much improved performane.

Many OEM's are specifing M1 motor oil (GM, Porche, BMW, etc., with more signing on all the time) and I know GM is using synthetic it as factory fill in their newer differentials and as a recommended upgrade to others. Mercury marine requires synthetic in their Opti-Max and High-Perf models as well as their gear boxes, both as factory fill and as an upgrade to the ones that didn't originally spec it. Even my air compressor requires (by the manual) using M1. I have seen dyno tests showing HP improvements with M1 with many drag racers are seeing improved ET's. Modest, yes, but improvements. M1 does not break down and leave deposits in you engine. While most newer oils don't do it to the extent that they used too, they do it by adding better detergents. M1 in inherently cleaner so it doesn't require the use of so much detergent. And detergents aren't good for an engine either.

Well, as I said, I could fill a book with specific personal instances if I get into all the improvements I have seen in the cars. Maybe not as impressive to me as that first (and many others bikes, including a GSX-R750) but very impressive to say the least. But I'll stop right here as this could go on for days.

I have never seen any problems with M1 that others have posted about. Oil leaks and such. Never, not one. As a side note, I now go to Wal-mart for oil changes ($27.88). Thats cheaper than the dino stuff at some of the quick change places. The mgr there said M1 changes are accounting for over 10% of his oil changes, and going up all the time. Dosen't mean much but I was surprised it was that high knowing how cheap (not necessarily bad) most people are when it comes to these things.

Truer words could not be spoken, hell id probly void the damn warranty on my bimmer by putting organic in knowing how BMWNA is.

I have used synthetic motor oil (Castrol) for 15 years in new cars and have always believed it to be the best. I have heard using synthetics in a used car that has been using organic motor oil would cause deposits in and around the rings to loosen causing you to start burning oil. Are you proponents of synthetics suggesting that you can start using Mobile1 at anytime in a cars life and it will only improve performance?.........ThomasO

I have used synthetic motor oil (Castrol) for 15 years in new cars and have always believed it to be the best. I have heard using synthetics in a used car that has been using organic motor oil would cause deposits in and around the rings to loosen causing you to start burning oil. Are you proponents of synthetics suggesting that you can start using Mobile1 at anytime in a cars life and it will only improve performance?.........ThomasO


Yes, I've always used it in used cars. No problems, ever. And even if it did loosen deposits, that is a good thing to me. I have never had one use more oil than normal. Which in my case, I don't bother checking between oil changes most of the time. Unless I am pulling a few thousand miles.

JAO

If you have 1000 miles without any symptoms you are OK! Wait awhile to do it the right way...maybe 5000 miles. Let the new fluid clean it out.

If I were you, I wouldn't panic. I believe you're going to be just fine. And so will your car. Is the tranny flush the best thing for it? Probably not. I used to have it done to my cars, and had no troubles whatsoever. On the surface, it seemed like a harmless enough procedure. Out with ALL the bad and in with ALL new. Right?

But then the cost shot up $30, and I began to ask questions. That's when stories of running the tranny dry and other horror stories surfaced. I can't prove any of the stories to be true, but combined with the increased cost, I decided against it. I'd rather drain the pan a couple times a year, than pay some guy $99 for a procedure of which I'm uncertain.

I say live and learn. Take a deep breath. Stop worrying about it. And next time, take a different route.

It's my understanding that the main reason there are horror stories regarding automatic transmissions going south soon after a flush has been performed is related to the breakdown of internal seals which were basically shot prior to the flush but the old, dirty and worn out fluid had ceased to perform it's function of lubricating etc., when fresh new fluid is introduced into a neglected system it has a tendency to cause a failure by either dislodging deposits or further damaging seals which were already worn but hadn't completely gone because the old worn out fluid was not adversely affecting them. Not to say that it's not possible to get contamination from another's fluid with such a machine but this is just what's been explained to me.

This is why most places that I'm aware of who offer this service will not guarantee the work done on a car with more than 60K miles.

Personally, I have done it or had it done to five vehicles now and have never had a problem. After the initial flush, an annual drain, filter change (where applicable) and fill are sufficient. This service, coupled with an auxilary tranny cooler will extend the useful life of an automatic transmission IMO. I also use deeper pans where possible.

Fellas:

Thanks for all your feedback. While I am still kicking myself for making this decision, i do feel a little more at ease knowing that there are others who have done this procedure and have experienced no problems. Like I said before, i trust my guy down at the dealer and apparently this is the recommended procedure. So for now I shall keep my fingers crossed and hope things remain in good condition.

Thanks again guys. it's good to know where your friends are.

Fellas:

Thanks for all your feedback. While I am still kicking myself for making this decision, i do feel a little more at ease knowing that there are others who have done this procedure and have experienced no problems. Like I said before, i trust my guy down at the dealer and apparently this is the recommended procedure. So for now I shall keep my fingers crossed and hope things remain in good condition.

Thanks again guys. it's good to know where your friends are.

When you say it is the "recommended procedure" realize that it may be the recommended procedure for that dealer (because they make more money on the flush procedure than doing the job properly) but it is NOT the GM recommended procedure. That procedure is clearly outlined in the service manaul as dropping the pan, draining the side cover via the hidden drain plug and cleaning the screen.

I would still recommend the proper procedure.

When you say it is the "recommended procedure" realize that it may be the recommended procedure for that dealer (because they make more money on the flush procedure than doing the job properly) but it is NOT the GM recommended procedure. That procedure is clearly outlined in the service manaul as dropping the pan, draining the side cover via the hidden drain plug and cleaning the screen.

I would still recommend the proper procedure.
I totally agree with this. The flush is popular because it is a low talent, low labor, and therefore, high profit procedure. Shops around here charge $99.00 for the flush. It takes them less than 20 minutes to do. An hour of labor is $60.00 around here. And fluid does not cost that much. Think about it.

The proper way is to drop, drain, clean etc.

That settles it then. I will go back and have them re-drain and change the fluid. You can obviously tell that I do not perform my own maintenance as I am far from being a mechanic otherwise I would have known about the shop manual's recommended procedure. Thanks again guys....