Topic: Transmission fluid

[AlekStooge]

I have a 2012 Silverado that is due for a transmission service. The owners manual says replace the fluid at 97,500 (strange.. I thought it was usually 30K-50K). I got 103,000. I asked this to a hand full of people and got mixed responses.

My questions is this should a drain and refill be done or a flush. With my research and responses from Chevy dealers and the net, people who are against the flush say it may cause complications because of the mileage and it seems they don't recommended the drain and refill either. Basically I get the vibe they don't know what to tell me.

On the other hand I heard flush is best because you actually get all the fluid out of transmission and torque converter not just 40% of it. They says the only reason you hear people have complications is because they have another transmission problem and they think a flush will fix it, which it won't.

According to the service records neither a flush or drain and refill was done by the previous owner ever.

[eigenvector]

You seem aware that flushing won't cure anything mechanical or wear related - so with that in mind.  I'd flush it.  100k is a lot of miles, 100k is a lot of miles between changes.  100k is a long time between changes, so if you understand the limitations of a flush, might as well spend the extra money and try to get as much of the old fluid out as you can.  It's not like you're spending this kind of money every year or something.

[City Boy]

Hi.Check converter also for drain plug.My Ford AOD has one.

[70CB750]

Hi.Check converter also for drain plug.My Ford AOD has one.

It is worth the effort to ad a drain plug to the pan if your car does not have one.

[madmtnmotors]

If you are concerned about the remaining old fluid by only dropping the pan, then do this:

>Drop the pan and change the fluid and filter
>Drive it until the next oil change and drop the pan again and replace the diluted oil that you drain out of the pan. The filter should not need to be replaced at this point.
>Begin a regimen after this of dropping the pan and replacing the fluid/filter every 40K to 50K miles.

Changing the fluid by either method in and of itself would not cause issues with a "high mileage" transmission. It's the "high mileage" that causes issues and running old fluid accelerates wear. So change the oil pronto, either method is acceptable, just do it.

[AlekStooge]

Thanks for the input.

If you are concerned about the remaining old fluid by only dropping the pan, then do this:

>Drop the pan and change the fluid and filter
>Drive it until the next oil change and drop the pan again and replace the diluted oil that you drain out of the pan. The filter should not need to be replaced at this point.
>Begin a regimen after this of dropping the pan and replacing the fluid/filter every 40K to 50K miles.

Changing the fluid by either method in and of itself would not cause issues with a "high mileage" transmission. It's the "high mileage" that causes issues and running old fluid accelerates wear. So change the oil pronto, either method is acceptable, just do it.

I like this idea!

[madmtnmotors]

Thanks for the input.

If you are concerned about the remaining old fluid by only dropping the pan, then do this:

>Drop the pan and change the fluid and filter
>Drive it until the next oil change and drop the pan again and replace the diluted oil that you drain out of the pan. The filter should not need to be replaced at this point.
>Begin a regimen after this of dropping the pan and replacing the fluid/filter every 40K to 50K miles.

Changing the fluid by either method in and of itself would not cause issues with a "high mileage" transmission. It's the "high mileage" that causes issues and running old fluid accelerates wear. So change the oil pronto, either method is acceptable, just do it.

I like this idea!

I can do that even one better. Instead of dropping the pan for a second time at the next oil change, I have been known to remove the fluid from the pan using a vacuum pump. The small hand held manually operated Mity-Vac is what I use, it just takes a few fillups of the 8oz container that comes with it, you just need a long suction hose to feed down through the dipstick tube. Pour the evacuated fluid into a graduated container and when you've removed all you can you will know how much to put back in. I can usually draw about three quarts, depending on the depth/capacity of the pan. This could even be done between filter changes at every 20K to 25K miles.

[hsas.69]

Shops have flushing machines that hook up to the cooler lines and will replace all of the oil. A typical transmission holds roughly 16 quarts dropping the pan only changes 6 or so. I would recommend have the whole system flushed and then deopping the pan and changing the filter.

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[strynboen]

is the cost very heigh for get the system flushed?..as home mecanic i think to remove the sump..and get the filter kleanet good up..only kosts the oil and time

they must be using a hell lot of oil to flush the running system..so no air komes in the system

[mrbreeze]

A trans flush is expensive but you only need it once in a great while so it's worth the expense. Transmission maintenance is one of the most over looked items on autos. If you do lots of towing it's even more critical. I like the idea of sucking the old stuff out with the mighty vac from time to time or installing a drain plug in the pan. Keeping an eye on the fluid level and color is also good practice.

[MikeSimon]

Shops have flushing machines that hook up to the cooler lines and will replace all of the oil. A typical transmission holds roughly 16 quarts dropping the pan only changes 6 or so. I would recommend have the whole system flushed and then deopping the pan and changing the filter.

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What tranny has 16qts = 4 gallons of oil in it?

[ofreen]

My questions is this should a drain and refill be done or a flush. With my research and responses from Chevy dealers and the net, people who are against the flush say it may cause complications because of the mileage and it seems they don't recommended the drain and refill either. Basically I get the vibe they don't know what to tell me.
On the other hand I heard flush is best because you actually get all the fluid out of transmission and torque converter not just 40% of it.

Clearly fresh new fluid is better for the transmission than old dirty fluid. So why do so many people report problems on neglected transmissions after fluid changes or flushes? The reason usually is because dislodged crud gums or plugs up something in the valve body. If you ever take apart a valve body you'll see how tight the passages are and how close the tolerances are for all the valves in their bores. It doesn't take much to get something stuck and when even one valve doesn't behave like it should, you have a "transmission problem" that somebody is going to want a lot of money to fix. But really cleaning out a valve body isn't that complicated of a job on most vehicles, just a little fiddly.

[hsas.69]

Shops have flushing machines that hook up to the cooler lines and will replace all of the oil. A typical transmission holds roughly 16 quarts dropping the pan only changes 6 or so. I would recommend have the whole system flushed and then deopping the pan and changing the filter.

Sent from my LGUS992 using Tapatalk

What tranny has 16qts = 4 gallons of oil in it?

Pretty well any automatic transmission on the road takes 16 or more quarts to fill from completely empty

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[hsas.69]

My questions is this should a drain and refill be done or a flush. With my research and responses from Chevy dealers and the net, people who are against the flush say it may cause complications because of the mileage and it seems they don't recommended the drain and refill either. Basically I get the vibe they don't know what to tell me.
On the other hand I heard flush is best because you actually get all the fluid out of transmission and torque converter not just 40% of it.

Clearly fresh new fluid is better for the transmission than old dirty fluid. So why do so many people report problems on neglected transmissions after fluid changes or flushes? The reason usually is because dislodged crud gums or plugs up something in the valve body. If you ever take apart a valve body you'll see how tight the passages are and how close the tolerances are for all the valves in their bores. It doesn't take much to get something stuck and when even one valve doesn't behave like it should, you have a "transmission problem" that somebody is going to want a lot of money to fix. But really cleaning out a valve body isn't that complicated of a job on most vehicles, just a little fiddly.

The high detergent content of tranmission fluid can wipe out the clutches if the transmission is severly worn the old fluid is better off left alone.

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[ofreen]

http://www.tciauto.com/tc/fluid-capacity/

[faux fiddy]

My questions is this should a drain and refill be done or a flush. With my research and responses from Chevy dealers and the net, people who are against the flush say it may cause complications because of the mileage and it seems they don't recommended the drain and refill either. Basically I get the vibe they don't know what to tell me.
On the other hand I heard flush is best because you actually get all the fluid out of transmission and torque converter not just 40% of it.

Clearly fresh new fluid is better for the transmission than old dirty fluid. So why do so many people report problems on neglected transmissions after fluid changes or flushes? The reason usually is because dislodged crud gums or plugs up something in the valve body. If you ever take apart a valve body you'll see how tight the passages are and how close the tolerances are for all the valves in their bores. It doesn't take much to get something stuck and when even one valve doesn't behave like it should, you have a "transmission problem" that somebody is going to want a lot of money to fix. But really cleaning out a valve body isn't that complicated of a job on most vehicles, just a little fiddly.

The high detergent content of  NEW tranmission fluid can wipe out the clutches if the transmission is severly worn the old fluid is better off left alone.

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+1
I'm pretty sure that my high mileage Toyota Vanwagon  I bought used finally died because of maintenance. The detergents do loosen up the 1/4 million miles of crud that is stuck on and fine where it is for the most part.

I bet if they marketed non-detergent transmission fluids they would be highly recommended for high mileage application and they would sell as much as the regular stuff.  It's really easy to ignore maintaining an automatic until issues arise, or issues can arise or become more problematic after neglect followed by a "regular"  maintenance.

[RAFster122s]

My 2000 Ford Crown Victoria Police Interceptor has 13 quarts in it and if the Torque Converter was able to be drained a few more quarts there.

Dropping pan and cleaning or replacing the filter every 60K and monitoring the fluid for color change is how I do it.

It has a lifetime gasket from the factory, as long as the pan is undamaged.

David

Shops have flushing machines that hook up to the cooler lines and will replace all of the oil. A typical transmission holds roughly 16 quarts dropping the pan only changes 6 or so. I would recommend have the whole system flushed and then deopping the pan and changing the filter.

Sent from my LGUS992 using Tapatalk

What tranny has 16qts = 4 gallons of oil in it?

[Bailgang]

The high detergent content of tranmission fluid can wipe out the clutches if the transmission is severly worn the old fluid is better off left alone.

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Good point. Many moons ago when I was a young mechanic I changed the trans fluid in I believe a Ford FMX or maybe a C4 and the fluid that was in it was burnt to a crisp. This particular Ford trans had a drain plug on its torque converter so I was able to drain most of the old fluid out after dropping the pan which was full of crud and replacing the filter and put fresh fluid in. The owner of the car (which happened to be my bosses mom  ) then took the car on a long road trip and after getting about 500 miles down the road the trans had a catastrophic failure. When we got the car back and sent the trans to the shop that did all our transmission rebuild work it turned out it was so catastrophic that there was nothing usable of the trans not even the housing. When my boss asked what would cause such a failure the first thing the trans shop asked was how badly burnt was the old fluid? When we said it was pretty bad the trans shop said that was probably the reason, the damage had pretty much already been done but putting fresh trans fluid in it and as highly detergent as it is probably loosened some crud up and it cascaded from there. Much to my relief because that meant it wasn't my fault. Lesson learned here was don't wait till your trans fluid is burnt before you finally decide to change it.

[eigenvector]

Incidentally, and why I said what I said.

The manual say "replace" the fluid.  Dropping the pan will not replace the fluid.  The only way to do that is by flushing.

For the cases where flushing causes the tranny to drop gears and the like - those are transmissions that were on the slim edge of dying anyway.  Since your owner's manual says every 100k - that's likely not the case here either. 

All of that said - there's nothing wrong with just dropping the pan and servicing the filter like Cal suggested.  Plenty of people do that and their auto trannys are working just fine.  Still - 100k between changes is a very long time and so long as you take it to a reputable place it should only be about 150 to 200 bucks.  No weird bells and whistles flush, no strange concoctions and brews - just transmission capacity + 5 quarts and warm enough to open the thermostat if it has one.

[AlekStooge]

Alright I'm doing the flush seems forum consensus is flushing won't hurt it, also given the manual says service every 97,500 not 30K or something... so that means to me it can't be that bad.

I think this is a good alternative for flushing opposed to power flushing with the machine. Skip to 7 min mark if you just want to see the procedure.

[RAFster122s]

You must keep ahead of the transmission pumping fluid out.  If it runs out then your pump is going to start wear on its parts and pollute your transmission with those tiny metal flakes.  Really bad thing to happen.

[grcamna2]

I think following the service intervals in the book completely is the Best preventive maintenance thing any vehicle owner can do and will sure give the maximum life to any vehicle.I sure hope more PO's get an education before they pass their problems on to the next owner.. 

[Bailgang]

For the cases where flushing causes the tranny to drop gears and the like - those are transmissions that were on the slim edge of dying anyway.  Since your owner's manual says every 100k - that's likely not the case here either. 

Still - 100k between changes is a very long time and so long as you take it to a reputable place it should only be about 150 to 200 bucks.  No weird bells and whistles flush, no strange concoctions and brews - just transmission capacity + 5 quarts and warm enough to open the thermostat if it has one.

This is how I roll too. Anecdotal evidence of failures due to fluid swaps is more than likely due to the renewed/increased hydraulic pressure being seen by the valve body. And if you think "not loosening up all the accumulated crud" is going to buy you 100k more trouble-free miles, well, I could not disagree more. Maintain your fluids (engine oil, transmission fluid, brake fluid) with strict regimens and your car/truck/bike will run far better, far longer.

I completely agree that maintaining fluids with strict regimens is the key. In the case of the Ford trans where I replaced the burnt to a crisp fluid with fresh fluid only to have it have a catastrophic failure wasn't the fault of the fresh fluid, that old fluid had to come out at some point in time but seeing how bad the old fluid was meant the damage had already been done and the trans was going to fail at some point soon anyhow. The fault was simply the owner didn't stick to a strict regimen and waited way too long to do something.

What pisses me off though is that some newer cars, in my case my wife's Chevy Cobalt its auto trans has no dip stick at all. The only way for me to check the trans fluid is to jack the car up and check it like an old school manual trans where I remove a threaded plug and see if any fluid dribbles out or stick my finger in to see what the fluid level is. I was pissed when I first found out about it during a routine fluid check, it's almost as if GM doesn't want me checking the trans fluid by making it inconvenient to do so.

[madmtnmotors]

Yeah, many new cars don't seem to have Trans dipsticks any longer. Even plenty have done away with the OIL dipstick instead relying upon internal level sensors. It "seems" the story at the Dealership these days is the Trans is a "sealed unit, 100k mile service guaranteed" from the factory. Well, that may be. But if I am paying the damn bill, you will jerk that SOB open, replace the filter and fluid, and you will do so while I stand here to confirm it. Comprende? 

Careful there Cal, Skynet make take issue with you tampering with the machine....     

[strynboen]

my new car is a 1974 ford.it have a dipstick for , engine and Automatic..and a rubber bumber in the bottom of the car to tramp on to spray sprintler fluid in the front schreen...and a manual choker as ekstra

.so tired of bad elektronic and alarm flashing/ lightning the vhole instrument board..some days i can not open the vindows..other days the car can only run idel..and cabine light turns on in the mittel of a ride and abs and engine safty varnings..lights.

.freanch cars is just fustrating.
..a bulp to(main light) to a new car, kosts more then i gave for the ford....and takes 6-8 auers to thange

.but i need some month rust vork..but then im back to the 70"