Trans flush question

Deuce450

Deuce450

Club Member
We are having a discussion on trans flushing. Half of the mechanics here think we should buy a machine that will flush the trans the other half thinks it is BS and that it will cause more damage in the long run. We do a yearly fluid and filter change on every trans every yr. Most of our trans are c-6. What is the thought from the board.
 
Deuce450 said:
We are having a discussion on trans flushing. Half of the mechanics here think we should buy a machine that will flush the trans the other half thinks it is BS and that it will cause more damage in the long run. We do a yearly fluid and filter change on every trans every yr. Most of our trans are c-6. What is the thought from the board.
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I too, dont like the idea of doing a flush. a trans only has so much psi. so lets say your c6 had 100psi(just an example) when it was new, after time the trans will start to wear and the psi will drop. then you hook it up to a flusher which can be anywhere from 200-300psi. now all the seals, internals ect... that have been used to <100psi are beat to shit with this higher psi. causing problems and a big headache in the long run. just my .02 though
 
I used to manage a transmission shop a long time ago when those flush machines first became popular at oil change places. I can't remember how many, but there were a lot that came in right after getting a flush that needed an overhaul.
 
BigWheelinBubba said:
I used to manage a transmission shop a long time ago when those flush machines first became popular at oil change places. I can't remember how many, but there were a lot that came in right after getting a flush that needed an overhaul.
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I think a majority of that is because your average person thinks a fluid change is going to fix their slipping trans. Even if you ask them they assume it's "not that bad" or "it just started" and don't bother mentioning it. When Belle had their trans flush machines, of the people who asked for the service we actually did it on maybe 1/2 of them. We always took it for a short test drive first to see if they were having problems, then went from there. We never had any issues at our store with them or comebacks though.
 
As Ryelou points out. Its is a case by case call. Also never flush a unit over 50K if its never been flushed.. Filter and pan that bitch. If you flush and filter the transmission every 35K it greatly extends the life of the transmission.
 
The question of trans failure after a flush was posed on a different forum. Not one person could personally say that they experienced, or new some who had experienced trans failure after a flush. Only people who said they had problems admitted that the trans had problems before the flush was administered.
 
We never changed or flushed our delivery truck.

1997 Chevy2500 5.7L 4L80E. 205,000 miles and still the original fluid and filter. Still shifts strong.

another

2005 Chevy2500 6.0L 4L80E. 140,000 miles and still the original fluid and filter. Still shifts strong.

I'm against it.
 
Well the BG tranflush machine uses the pressure from the trans itself to flush the trans, it does not apply any pressure itself. IMO its a good thing to do as scheduled maintenance, but its not intended to fix a slipping trans. The filter should occasionally be changed which is not done when flushing the trans (duh). A transflush will get out way more old dirty fluid then just dropping the pan and changing the filter alone will do. I personally like transflush machines b/c its a way cleaner and easier and more effective way to clean out the trans. :D
 
Deuce450 said:
We are having a discussion on trans flushing. Half of the mechanics here think we should buy a machine that will flush the trans the other half thinks it is BS and that it will cause more damage in the long run. We do a yearly fluid and filter change on every trans every yr. Most of our trans are c-6. What is the thought from the board.
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Buy a machine? Are you serious? Just how many vehicles do you have?
In your case, speaking on the c-6 transmissions, I would remove the pan, clean the shit out of it and install a magnet. Use a durapreme or farpak gasket, and remove the drain plug on the torqueconverter(all stock c-6 converters have drain plugs). If the pan is clean, and the screen looks clean, leave it alone. If you do replace the screen, use a sealed power filter only and a gasket. Make sure you install the one bolt that is longer back into the correct location. Use a quality dexron/mercron fluid, and a bottle of lubeguard additive. If your really picky, a brand new pan thats thicker than the original is available for about 20 bucks(2 wl dr only). Drill a 1/2 " hole in the pan and tack a short 1/2 24 nut on the inside and use a engine oil drain plug with a viton seal, and now you have your own drain plug installed, which makes future fluid changes much easier. By removing the pan, you can see if a failure is about to accure, if you know what to look for.

Flush machines are for making money, and a life saver for unskilled laborers that are not capable of removing/resealing making adjustments and inspecting the condition of the trans with the pan off. The flusher also stir up any sediments that do not get cleaned out, sending them, in your case, back through a metal screen and into the pump & valvebody.
 
Dropping the pan and changing the filter only changes about 30% of the Trans fluid. The machine I use hooks into your trans lines and uses the trans pump to push a piston up a cyl that pushes the new fluid into the trans. This way you’re getting everything from the cooler, torque convertor, and transmission. Ford and Chrysler recommends flushing it every 30000 GM every 50000. When I do mine I’ll do the flush first then change the filter when I'm done. There is a point you don't want to change it. At about 60000 if it has never been changed I don't do it. If there’s a problem with a trans slipping or not shifting correctly a flush will not fix it and may make it worse. I do about 3 flushes a day w/o changing the filters, and have cars coming back with over 200K + running the same transmission without problems but they have done them according to the manufactures schedule. :cheers:
 
superstang9085 said:
Well the BG tranflush machine uses the pressure from the trans itself to flush the trans, it does not apply any pressure itself. IMO its a good thing to do as scheduled maintenance, but its not intended to fix a slipping trans. The filter should occasionally be changed which is not done when flushing the trans (duh). A transflush will get out way more old dirty fluid then just dropping the pan and changing the filter alone will do. I personally like transflush machines b/c its a way cleaner and easier and more effective way to clean out the trans. :D
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x 2 most people dont understand how the machine works but they think they know bg flush machine ftw
 
what if my trans doesnt slip, but from time to time has violent torque converter shutter on gradual acceleration, only when up shifting?
 
Detroit Gearbox said:
Flush machines are for making money, and a life saver for unskilled laborers that are not capable of removing/resealing making adjustments and inspecting the condition of the trans with the pan off. The flusher also stir up any sediments that do not get cleaned out, sending them, in your case, back through a metal screen and into the pump & valvebody.
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Atlest it changes the fluid and helps the customer feel good about servicing there cars. And who knows just Maybe the trans will last longer. Time will tell.
 
kovacs32 said:
what if my trans doesnt slip, but from time to time has violent torque converter shutter on gradual acceleration, only when up shifting?
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If your converter is shuttering, its bad. However, changing the fluid, and adding anti shutter additive will make it stop shuttering. It will last for about a year or more, and eventually it will come back. (actually, the anti shutter stuff alone will make it stop shuttering)
Coolerline pressure, and main line pressure are not the same. Most vehicles have coolerline pressure between 40-60lbs. Some vehicles (explorers, mustangs with a 5r55w/s transmission have a thermatic valve in the pump that open & close with temperature, and actually have no cooler line flow when cold. Attempting to flush them by attaching a flush machine can cause damage. Also in many fords, crown vics, trucks, have a valve in the cooler that by passes the fluid when cold. That fluid becomes trapped. Each vehicle and each trans is different, so the same procedure for each vehicle does not apply. Sediments, metal, clutch material, tend to accumulate in the pan, and on the magnet(which most vehicles today have) And they accumulate near the intake of the filter. The sediments plug or restrict the flow to the pump. You would be surprised how much shit is inside a filter until you bust one open and separate the Dacron material. Cleaning out those sediments is important.
Changing fluid & filter never makes a transmission go bad. If you have problems soon after replacing both, either the transmission was already going bad, or the mechanic that did the work did it incorrectly or used inferior parts. Many "Murray's" type replacement filters are inferior, and I have seen first hand many failed transmission from a improperly engineered or improperly installed filter.
The 30% number you posted roadster is more like 50-60%, but once again every vehicle and every trans is different.
 
Detroit Gearbox said:
If your converter is shuttering, its bad. However, changing the fluid, and adding anti shutter additive will make it stop shuttering. It will last for about a year or more, and eventually it will come back. (actually, the anti shutter stuff alone will make it stop shuttering)
Coolerline pressure, and main line pressure are not the same. Most vehicles have coolerline pressure between 40-60lbs. Some vehicles (explorers, mustangs with a 5r55w/s transmission have a thermatic valve in the pump that open & close with temperature, and actually have no cooler line flow when cold. Attempting to flush them by attaching a flush machine can cause damage. Also in many fords, crown vics, trucks, have a valve in the cooler that by passes the fluid when cold. That fluid becomes trapped. Each vehicle and each trans is different, so the same procedure for each vehicle does not apply. Sediments, metal, clutch material, tend to accumulate in the pan, and on the magnet(which most vehicles today have) And they accumulate near the intake of the filter. The sediments plug or restrict the flow to the pump. You would be surprised how much shit is inside a filter until you bust one open and separate the Dacron material. Cleaning out those sediments is important.
Changing fluid & filter never makes a transmission go bad. If you have problems soon after replacing both, either the transmission was already going bad, or the mechanic that did the work did it incorrectly or used inferior parts. Many "Murray's" type replacement filters are inferior, and I have seen first hand many failed transmission from a improperly engineered or improperly installed filter.
The 30% number you posted roadster is more like 50-60%, but once again every vehicle and every trans is different.
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Thanks for the info on the ford explorers, mustangs with a 5r55w/s transmission I had heard they were controlled by thermatic valve in the pump that open & close with temperature. But never had it verified by someone who has been inside them before. That explains why it 45-60 mins. for them to flush. Also never realized that the filter had that much shit in them. Guess I should take one apart one day. Well I learned a couple things today. Who says you can't teach an old dog new tricks. lol Thanks Gearbox :cheers:
 
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