Changing Auto-transmission fluid

Is this a difficult procedure? Should I pay the

99 bucks at Jiffy Lube to do it, or is it something that I can do on my own? I have a 99 S-10 and a father that is very good with cars....just looking for some opinions. Thanks.

DK

Reply to
Dave King
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I can tell you about a lesson I learned the hard way...

I had a Cadilac Fleetwood several years ago that I took to a Jiffy Lube. They suggested that I have the transmission fluid completely replaced. Since I had bought the car used (at a dealer auction) and had no idea of the service history, and it did have over 100,000 miles, I figured it was probably a good idea.

Within a month, the transmission crapped out, slowly but surely. Had to buy a used one to replace it. My father, who is a used car dealer (and former new car dealer) said his mechanic said you should NEVER replace transmission fluid after a vehicle reaches over 100,000 miles. I forget the reason he cited exactly, but it had to do with it causing more flakes of metal to come loose and screw up the transmission. I am curious as to the opinion/experience on this of others.

Reply to
Frisbee® MCNGP

transmission

OK, thanks for the info....however, my 99 S-10 only has 38,000 miles on it. The technician at Jiffy Lube showed me the color of the auto-transmission fluid in my truck (light brown) compared to the color of new fluid (pink/bright red). He recommended that it be changed. Anyone else have helping ideas?

DK

Reply to
Dave King

Just change the filter.

CJ

Reply to
CJB

Reply to
George

I think the idea of flushing the transmission is a bad thing for the reasons stated in a previous post.

I do know for a fact that the color of the fluid doesn't mean a thing. The odor it gives off will tell you more. Should smell, well...., oily, but not any trace of burned, as in burnt toast kind of a thing. If you changed fluids based on the color, you would have to change your engine oil every time you drove it :-) Look at the dipstick, and then look at the appearance of unused oil, and then go tell the Jiffy Lube guy to stop spreading manure around the shop

It was mentioned to drop the pan, and if you have a drain plug in it, that would be easy. I have, in the past, siphoned the fluid out of the trans through the filler tube. There are hoses and adapters to get you there. This doesn't get all the fluid, the amount depends on the transmission, but I think it is a pretty safe method to getting some of the fluid out, and replacing it with cleaner oil, without much risk of messing up a working transmission.

I would avoid ever opening a working transmission. Dirt, other particles, dislogded o-rings, or check balls will ruin your day, and your wallet :-)

Just IMO,

John

Reply to
jbrush

transmission

Your fathers mechanic gave you the biggest load of BULLSHIT I've ever heard. When fluid is old and expired it loses it's ability to lubricate, hence is useless. Leaving it in just exacerbates the problem and AT damage will ensue. Replacing old ATF with new restores the lubrication and protects the AT internals. Leaving old stuff in is the dumbest thing one can do. Looks like pop needs a new mechanic. This is true on any vehicle, regardless of mileage.

Your AT crapped out on the Caddy because Jiffy Lube didn't do the job correctly (can they do anything right?>.

Doc

>
Reply to
"Doc"

there are two basic types of "flushing" machines, the "backflush" type which has the rep of killing trannies and the newer type (trans tech is one brand) which simply allows the trans pump to pump out the old fluid while it infuses new fluid via the cooler lines. these machines are what most dealers and shops use. they can very precisely match the flow rate and pressure of the trans pump.

ATF isn't engine oil..... color is very important, if it's not red it's toast.

The

it should smell like ATF.

again, engine oil isn't atf, if it smells burnt at all it needs to be replaced pronto.

dropping the pan and changing filters changes between 1/3 and 1/2 of the fluid. if you keep a decent filter schedule (15k for non severe use) it'll keep the additive package fresh in the ATF.

if you don't drop the pan and change the filter, you're missing half the ball game. you won't have any dislodged O rings or checkballs by simply changing the filter... that would require removing the valve body.

-Bret

Reply to
Bret Chase

Reply to
Markeau

Sorry to disagree, but one cannot judge the condition of ATF by looking at the color. That is not the way it is done.

However, I am wrong in that I seem to have mistaken the thread for one dealing with what to do with an older transmission that has not been serviced, and is getting up in the mileage. I thought the original poster was asking about the wisdom of using jiffy lube on an older transmission, and had mentioned that the 'tech' told him his fluid was bad because it was dirty looking, which is a total pack of lies.

Well, yea, I pretty much said that. Thanks for verifying my statement.

Golly, that is exactly what I said. If it smells burned, its hosed. You said you change it based on the color, and now you change it based on the odor. Only one of those is a valid method, and it ain't the appearance one. The color is not the way to determine if the fluid is still good or not. If you go by color, you will be spending a lot of money on ATF over the years.

Like I said, I was mistakenly of the impression we were discussing the average transmission with tons of miles that has never been serviced. There are very few of those around. Obviously, the way one would deal with a new trans involves all the required maintenance and changes of fluid and filter.

If I had a transmission with high miles, like 120K, on it that was functioning properly, but had not been serviced, I would not ever drop the pan, nor would I let Jiffy Lube or any other shop of horrors do a flush out job on it. I know I am the only one here who thinks that way, but I reserve the right to use years of experience to make my choices and to voice my opinion.

Usenet. What a joke.......

Thanks,

John

Reply to
singlewc

Hey doc, you mean you don;t use those infglatable filters they sell now. They install like breast implants, that only need a little hole to get them in. NOt like the old ones where you got cut all to hell and back. No need to dropa pan anymore. Just shove em down the dipstick tube. Slickest thing I have seen a long time. And as you already said, there is always Jiffy lube, the masters of the car care world! Visit my website:

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Reply to
Roy

I have a friend that was in the tranny business all his life with his father. he is now retired but tinkers in a backyard shop. When we changed the filter and fluid on the wifes Toyota and my GMC truck we dropped the pan, cleaned it well, replaced the filter, reinstalled pan and gasket. Filed up the tranny, and then broke open the dishcharege side of the tranny cooler lines from the radiator back to the tranny, cranked the engine up placed the end of thre hose in a can and when the fluid started to spit and putter, shut it off imediately, topped off the tranny again, and repeated the enigne run until spit and sputtering of fluid started again, and repeated this until the fluid came out the color of the fresh fluid. That was over 30,000 miles ago on my truck, so I don;t think it hurt anything. I plan on doing it again this weekend at my own shop now that I seen how it was done. Visit my website:

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Reply to
Roy

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