Well written article on why ANY trans flush is bad

[ford46guy]

(sorry, accidentally cross posted). GM says NO NO NO to any service other than a pan drop. (Unless you feel this is an ulterior motive :lol:) https://static.nhtsa.gov/odi/tsbs/2012/SB-10062497-7690.pdf The use of external transmission fluid exchange or flush machines is not recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following procedures in Service Information (SI). Refer to Automatic/Manual Transmission Fluid and Filter Replacement. And even if you exchange 12 qts in a flush (using the cooler lines, no machine), since the trans in P has lots of circuits blocked off, you are lucky to exchange 1/2 the fluid. And if you do flush, don't even think of doing it without a filter change. http://www.agcoauto.com/content/news/p2_articleid/238 I recently did a pan drop/filter and was thinking of doing a fluid exchange thru the cooler. Then I read people sell those Lexus and Toyota trans with 250K and never touched any fluid. Still run like new. In the early 90s after hs I worked briefly for a neighbor in a busy NYC transmission shop. He said if everyone did a pan/filter drop at 30K he would be out of business. He also said never to flush, either you waste money or will damage the unit. Zero benefit. He also said you never exchange all the fluid. He also said trans fail after flushes because of clogged filters. He has seen many. If fluid is that contaminated that you need to be replaced it you have bigger problems. Now, with the new fluids the interval may be 60-100K.

 

[joekingcorvette]

I guess I disagree. I just had my 2014 F-150 fluid changed at about 51,000 miles. I pull a boat and believe it's good insurance for the transmission to be serviced. People are quick to buy when they see the maintenance record when I sell. I do have the filter replaced too.

 

[CorvairGeek]

Too bad the franchise agreements don't prevent (or do they not enforce?) various, unapproved "wallet flush" service.

 

[Cujet]

It's good to remember that the transmission's pump draws from the pan. When a flush is performed, what really happens is that a good bit of your new, expensive and fresh fluid is pumped right into the drain tank. While a good bit of old fluid remains mixed in, and also in the valve body, torque converter and and actuators. On my F150, with 6R80 trans, it takes about 8-9 quarts to refill after dropping the pan. Total capacity is 13 quarts. At best, either method is a partial replacement of the fluid. Since I weld a drain plug on to the pan, it's really easy to do subsequent changes to ensure more fresh fluid.

 

[irad]

I replace trans fluid through a cooler line. I keep replacing until the stuff coming out is the same color as the stuff I'm putting in. Usually takes 11 or 12 quarts every 45000 miles.

 

[CT8]

Clean oil is happy oil regardless where it is located .Changing engine oil doesn't give a 100% change either. Change half the oil you approximately get a 50% drop in contaminants.

 

[JTK]

I see this as very old and inaccurate info and perhaps a way for the OEMs to keep vehicles in their dealer service network. If this is referring to an ATF exchange machine, all that is is a fluid transfusion where the machine is hooked into the cooler line circuit. Because of the design of the twin cylinder fluid exchange machine, the fluid that is pumped out is replaced by that exact amount of new fluid.

 

[4WD]

The solution to pollution is dilution … once I do my first pan/filter/magnet job - a drain plug is going in and I'm going to freshen up a few quarts now and then … 20 minute job, clean, neat and easy enough to keep procrastination away. For those who like it … Derale has a 4 port remote filter (2 spare ports plugged)

 

[pbm]

All I've ever done on my A/T's is a D&R (never did a flush) and I've never had a transmission problem. On my current 16' Ford Escape with the 6F35 I've replaced 4.25 quarts twice already coming up on 40K. I've used Castrol Full Synthetic (which is Mercon LV approved) and added LG red both times. I feel that doing this will replenish additives and keep the tranny working fine. If I bought a used car I'd probably do a few D&R's to get rid of contaminants and bring the fluid back to being red unless the previous owner showed regular fluid changes. IMO, 'flushing' isn't necessary for the tranny or the motor (some dealer's try to sell an engine flush service to lighten your wallet...) PS: After reading the post previous to mine (by 4WD) I have to agree ….that dropping the pan and cleaning the magnets are a good idea on the initial fluid change when there is a lot of ferrous debris...On my Buick 4T65 I dropped the pan every time I changed the fluid and cleaned the magnets....I noticed less and less debris with each pan drop...

 

[ABN_CBT_ENGR]

Originally Posted by ford46guy

(sorry, accidentally cross posted). GM says NO NO NO to any service other than a pan drop. (Unless you feel this is an ulterior motive :lol:)

Nothing ulterior or sinister about it. I deal with this all the time on equipment I either flush or have to do the RCFA on one that was improperly flushed. It seems industrial equipment manufacturers are quicker to answer "why" rather than auto manufacturers and I suppose that adds to the "mystery". The answer is plain and simple- its the avoidance of a potential legal liability. Its easier for them to just "say no" and not have to address it any further. Here's why. If they say "flush" is a recommended function- then they would have to investigate, publish a process and most likely list of chemicals etc. ( significant cost to develop this). If they didn't do this then they are in effect saying 'any" version of a "flush" is OK- that opens doors to liability. They know there is no absolute definition of a flush, no guarantee of the process or control of chemicals etc- they simply refuse to get involved. They know an improper flush can damage the equipment and they cant control that either. They also know people would 'swear on a stack of bibles" they did everything "by the book" and now incur additional costs ( even with nuisance settlements) for all kinds of claims. Its just easier to say no and stop it before it starts at the OEM level. That's all.

 

[csandste]

Originally Posted by ABN_CBT_ENGR

Originally Posted by ford46guy

(sorry, accidentally cross posted). GM says NO NO NO to any service other than a pan drop. (Unless you feel this is an ulterior motive :lol:)

Nothing ulterior or sinister about it. I deal with this all the time on equipment I either flush or have to do the RCFA on one that was improperly flushed. It seems industrial equipment manufacturers are quicker to answer "why" rather than auto manufacturers and I suppose that adds to the "mystery". The answer is plain and simple- its the avoidance of a potential legal liability. Its easier for them to just "say no" and not have to address it any further. Here's why. If they say "flush" is a recommended function- then they would have to investigate, publish a process and most likely list of chemicals etc. ( significant cost to develop this). If they didn't do this then they are in effect saying 'any" version of a "flush" is OK- that opens doors to liability. They know there is no absolute definition of a flush, no guarantee of the process or control of chemicals etc- they simply refuse to get involved. They know an improper flush can damage the equipment and they cant control that either. They also know people would 'swear on a stack of bibles" they did everything "by the book" and now incur additional costs ( even with nuisance settlements) for all kinds of claims. Its just easier to say no and stop it before it starts at the OEM level. That's all.

I've done three flushes on GM and HyunKia's without incident. I think this, like discouraging oil additives, is a pretty good summation of manufacturers' objections. Lots of lawyers at work here.

 

[gfh77665]

Originally Posted by ford46guy

He also said never to flush, either you waste money or will damage the unit. Zero benefit. He also said you never exchange all the fluid.

Zero benefit to having new fluid in the Trans? Seriously?

 

[irad]

Even my daughter, the mechanically inept one, noticed a difference in the way her Passat drove on the highway after replacing 12 quarts through the cooler line.

 

[Trav]

This is a procedure for a GM vehicle. What is well written about that article? Other manufacturers specify similar procedures.

 

[4WD]

My next procedure: 1) Drain 5 quarts 2) Pour 5 quarts

 

[PowerSurge]

I don't do "wallet" flushes. Drain and fill performed by me. That's it.

 

[doitmyself]

Just two different acceptable methods to get new fluid into the transmission if done correctly. Lots of the new trannies don't have serviceable filters, so that nixes one idea. Liability issues aside, I interpreted the GM paper as simply an attempt by corporate to change the stealership culture that has become so pervasive. Do away with the money grab and get back to basic simple maintenance practices to develop a more trusting customer base. I cannot imagine that it worked.

 

[Yah-Tah-Hey]

I ran about twelve quarts of Mobil 3309 through my 04 Camry five speed AT in 08 and since then I have drained/refilled every spring. ATF stays looking like new. Works for me. Only problem currently is I don't have Walmart to take my full Jerry can of motor oil/ATF. Hope they plan to reoen their automotive department soon. Anyone know?

 

[Rand]

tons of stuff wrong with the article. Its also wrong to assume it applies to every vehicle. That whole article speaks to me of lawyers and dodging liability. An example: Hyundai/kia put drain plugs on many of their vehicles.. there is no pan to drop. and the only filter is a mesh rock catcher. SUPER! easy to drain and fill once a year after it gets 50000miles on it.. to keep the fluid fresh. since the fluid isnt toxic black goo.. you dont need to get 100% out and you dont need to clean anything.

 

[bbhero]

Originally Posted by 4WD

My next procedure: 1) Drain 5 quarts 2) Pour 5 quarts

There ya go man ^^^^^^^^^^ What I have done 4 times on my car.