# Waht kills transmissions?



## mkwl (Jan 21, 2005)

Every now and again someone'll post on here that their trans is "toast" or "dead", what exactly kills trannys (auto's)? What causes trans to lose reverse (or forward)? Was wondering...

Matt


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## bribrius (May 5, 2007)

shifting from drive to reverse and vice versa before coming to a complete stop and letting the motor idle down. over heating.


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## B&B (Nov 4, 2006)

mkwl;494993 said:


> what exactly kills trannys? Was wondering...
> 
> Matt


 1# killer...the driver.

Occasionally it's due to a poorly designed trans that can't do the job....


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## Flipper (Nov 1, 2001)

HEAT

Keep it cool and they will last forever.


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## tom_mccauley (Dec 10, 2007)

The object between the stering wheel and the seat back!!!

actually, heat causes the fluid to break down allowing the bands to become burnt/glazed same with the friction rings the get burnt/glazed and they lose the ability to grab one another.


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## abbert55 (Jan 13, 2006)

The biggest factor is heat buildup. If you can, install a trans cooler in the line coming from the trans going to the radiator. This will rid excess heat and provide longevity. A big factor in heat buildup is how the unit is driven. When plowing, the torque converter is not locked up causing slippage and heat. Also when pushing wet heavy snow (see pic in signature) (this can weigh several tons) don't cowboy the truck.... that is burying your foot in the gas (same as spuring your horse). Use common sense and you should have no problems. I've been plowing with automatics for 30+ years and have not smoked one yet.
Al


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## ChevKid03 (Dec 23, 2007)

mkwl;494993 said:


> Every now and again someone'll post on here that their trans is "toast" or "dead", what exactly kills trannys (auto's)? What causes trans to lose reverse (or forward)? Was wondering...
> 
> Matt


Matt, 
I have the same truck as you (Silverado) but extended cab. I just changed my fluid and filter yesterday. Worth the $50 and an hour of my time. Just don't overfill. Not hard to do either. Make sure you use DEX III fluid.


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## fatboy (Dec 6, 2006)

Most of the time when it comes to plowing its HEAT or abuse, once your trans get overheated the lubricity of the trans fluid go's away, which results in hard part failure or friction plates burning up, regular transmission service and good fluid go's a long way. I have had great results with Amsoil ATF, it has a much higher heat break down point.
Oh yea and remember your driving a truck and not a 966 CAT loader... and of course a good cooler is a must.
Here's a little tip...when stopped for a pee break or to get a coffee or in some case's put back what you just backed over......leave you truck in neutral and not park (make sure the plow is down and it won't roll away) this keeps the fluid moving and cooling, where as in park not as much and will help too cool faster.


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## RBRONKEMA GHTFD (Dec 17, 2006)

Tranny slamming it while plowing because your in a hurry. Take your time, and come to a complete stop. If you spin your tires stop before shifting.


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## Detroitdan (Aug 15, 2005)

Plowing puts a load on the tranny, this creates more heat. Your stock system for removing heat is compromised by one of two things. Either you are blocking the airflow with the plow while driving, or you are going slow while plowing and the airflow is insufficient. 
First thing you need is a temp gauge so you can see what you are doing to the transmission. You will be amazed at how fast the temps climb once you drop the plow. On my old trucks I always added a gauge, a big auxiliary cooler and an electric fan right on the cooler. About a hundred bucks and NEVER hurt a tranny. When plowing I would watch the gauge and in 5-10 minutes the temp was high enough that I had to flip the fan on. Eventually I got an automatic sender for the fan switch, but you get the idea.

It's real simple. Change the fluid and filter at least every year, and manage your fluid temp. 

You can also keep temps down by using 4 low whenever possible. Multiplies the torque and the tranny doens't work near as hard or get as hot. Just takes a little patience, and isn't appropriate for every job.


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## streetfrog (Dec 9, 2007)

And the other number 1 cause is lack of service. Especially being a plow truck you should have a FULL service every year. That means not only a filter change but ALSO a full fluid flush. Yes it's a bit more expensive to have both services done( filter change and fluid flush) But think about the cost if not done. reg $1700 + . That and a nice HD trans cooler.


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## 2dogs2 (Aug 25, 2007)

I bought a Liquivac several years ago, and suck out 4-5 qts of trans fluid twice a year, and put fresh in. Since I can't do power flushes to get all the fluid out of the torque converter, this at least keeps 1/2 of the fluid new.


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## BREAULT69 (Jan 15, 2008)

#1 killer is heat. One trans. heat up severely breaks the fluid down. If your eng. gets hot (your trans. is getting hot too) change the trans. fluid as soon as possible, flush machine is the best as it gets the converter too. Shift kits can shorten the time the friction material is slipping during a shift (soft shifts that Joe average truck buyer likes), this will extend trans. life. Using synthetic fluids can help due to their ability to take higher temp. 4x4 low is a big trans. life extender when operating at low speeds under load. The constant forward to reverse shifting during snow plowing is hardest on the trans. output shaft to transfer case connection and driveshaft slip yoke splines. Some modern transmissions just have weaknesses in their design. Many have updates / kits that address these problems and can prevent total trans. failures for a reasonable cost. Diesel engines that produce 500 ft. lbs. torque can destroy anything short of Allison automatics and dialed up diesels can even blow Allisons up.


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## RMHSR (Mar 17, 2006)

I thought I would give some input in reference to the flush machines. I talked to the transmission guy that I use and asked him about the flush machines and he said the problem he has with them is that you add a chemical to the transmission prior to the flush. This chemical loosens the build up of junk from the transmission. When the junk is undisturbed it finds a build up point either in voids or in the pan itself. Typically this junk isn't hurting anything until you disturb it then you have just reentered it into the interior components again. At least by dropping the pan you asure that a new clean filter is being replaced and then you can scrape any junk from the pan. Somehow he still circulates fresh fluid through the trans cooler but I don't really know how. That is why I pay him, he at least sounds convincing and I don't have to touch it. This is just one mechanic's opinion and I can't offer any scientific proof that either method is better than the other. I think this was just a drawn out way of saying "change your fluid".


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## mkwl (Jan 21, 2005)

My truck's got a stock trans cooler and temp guage (plow prep/towing packages), what's the highest temp a trans should get to plowing before getting concerned?


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## UNISCAPE (Oct 17, 2000)

Heat Heat Heat


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## B&B (Nov 4, 2006)

mkwl;496403 said:


> My truck's got a stock trans cooler and temp guage (plow prep/towing packages), what's the highest temp a trans should get to plowing before getting concerned?


The stock aux coolers on the 6.0/4L85E's are pretty good...but do what you can to keep it 200* or less (less is better of course).

If it gets much over 200*-210* ease up on it for a bit. By doing so, it will thank you in the long run by providing a longer service life.


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## mkwl (Jan 21, 2005)

UNISCAPE;496408 said:


> Heat Heat Heat


Yeah, I figured- I was able to keep the temp on my truck below 160* the last few storms, hopefully that's a reasonable temp (I don't want to kill my tranny!).

Also sent you an email response, thanks.


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## mike33087 (Feb 9, 2005)

basically the main killer besides heat is OMG PLOWING!


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## MickiRig1 (Dec 5, 2003)

Popping a cooling line and losing pressure will kill some transmissions. Like my C-6 in the F-250.


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## B&B (Nov 4, 2006)

RMHSR;496338 said:


> I thought I would give some input in reference to the flush machines. I talked to the transmission guy that I use and asked him about the flush machines and he said the problem he has with them is that you add a chemical to the transmission prior to the flush. This chemical loosens the build up of junk from the transmission. When the junk is undisturbed it finds a build up point either in voids or in the pan itself. Typically this junk isn't hurting anything until you disturb it then you have just reentered it into the interior components again.


 He taught you a good tip...

Transmission flushes are being sold left and right. But it's not a smart idea on a neglected trans.The idea is that by forcing cleaning solvents backwards through the system, it will get all the junk and garbage that has formed over time and "flush" it out of the system. In theory this may be sound, but in actual practice on a neglected trans, it's a gamble at best.

Flush machines do what they say; they force high pressure cleaning solvents back through the transmission in an attempt to clean out the accumulated debris that has formed. Transmissions have small passages and galleries through which fluid flows and there are one-way valves that keep the fluids from backtracking throughout some of these circuits. By using an aggressive cleaning procedure like flushing, accumulated sludge or varnish is forced backwards through these galleries and valves and, more often than not, lodge tightly and block them. This cuts off the normal flow of the fluid and can cause the lack of lubrication and abnormal shifting in a transmission.

Who recommends flushing as maintenance? The shops that want to sell you the flush that charge anywhere from $49.95 to $99.95 or more. And many state quite emphatically that it is recommended that it be done. But who actually recommends that it be done? GM, Ford, Chrysler, Nissan, Honda and several other OEM manufacturers won't recommend a transmission flush as routine maintenance. In fact, they specifically don't endorse them at all. The only ones who do recommend flushing as a maintenance procedure are the companies that sell the flush machines and the shops that buy them. The flush machine manufacturers state quite clearly in their operating manuals not to use their machines on "high-mileage vehicles". That simple statement proves that flushing is not a safe procedure. It also absolves them of any responsibility of any damage that may occur due to the use of their equipment. This leaves the shop wholly responsible for anything that happens and the cost of correcting the damage that occurs.

If you do frequent filter changes and service the transmission like it should be for the conditions it encounters, there is no need for a flush.


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## abbert55 (Jan 13, 2006)

In the good old days (circa 1970's) Transmission pans had drain plugs and so did the torque converter. We would drop all the fluid in both units, clean and inspect and refill. Nowadays, after you replace the trans filter you can still displace the old fluid in the TC and system by filling the trans and removing the return line from the cooler to the trans and idle the engine with the trans in park.Of course you will need something to catch the old fluid. You may need up to 12 qt. or more of trans fluid to flush clean but this way you know it is done right. The trans pump will flush the TC and lines if done this way. Hope this is helpful, Al


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## BREAULT69 (Jan 15, 2008)

I owned a repair shop and towing company for ten years, the last four we had an exchange machine (did not flush, we never put any type of chemical in). Total fluid exchange got a bad rap from the use of solvent cleaners and more importantly quick lube (other shops too) selling the service without pan removal and filter change. They were effectively stirring all the crap up that had accumulated to the bottom. The other thing is the fact that there are many types of fluid now and if a shop doesn't have about four different machines it usually means everybody is gonna get DEXRON. The exchange machine uses the trans. own pump to do the work so there is no reverse flow or extra high pressure envolved. As stated before if the manufacturers still put inspection covers and drain plugs on the converters there probably would be no fluid exchange machines. The converters can hold 50% of the fluid, you don't drain 2.5 qts. of oil out of your eng. then slam the plug back in do ya ? Flush=bad, exchange (with filter change)=good.


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## Detroitdan (Aug 15, 2005)

Let me ask this: is the fluid in the torque converter captive, and in there permanently, or does it get circulated along with the rest of the fluid?


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## B&B (Nov 4, 2006)

Detroitdan;497676 said:


> Let me ask this: is the fluid in the torque converter captive, and in there permanently, or does it get circulated along with the rest of the fluid?


No it's not contained, the fluid does travel through it. It couldn't work if it didn't.


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## Detroitdan (Aug 15, 2005)

B&B;497679 said:


> No it's not contained, the fluid does travel through it. It couldn't work if it didn't.


Right, so if it does circulate, why does everyone say it never gets changed unless you flush it? I've argued with a bunch of so-called tranny experts who told me to get it flushed. I told them that I change the fluid twice a year and the filter every other time, way more than is necessary so all that fluid is working it's way through. Not all at once, but it is getting mixed up and filtered and changed. And they still say you MUST get it flushed to change all the fluid. I had my pan down several times last summer trying to track down my OD problem. I replaced the fluid from the pan probably a half a dozen times over the course of a couple months and not too many miles. So when I try to explain that I'm getting all the fluid replaced gradually, they still say I need it flushed. Well, neither my fluid, pan, nor my filter has every even been dirty or dark, so I don't think I need to flush it, and I'm not interested in stirring up stuff anyway.


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## BREAULT69 (Jan 15, 2008)

What your doing is fine. It would be more of a problem for someone who doesn't routinely do this service. The fluid that stays in the trans & cooler, lines etc. is still pretty clean & viable in your case. But someone that only does it maybe every few years is mixing new fluid with broken down oxidized, contaminated fluid. If the old fluid has become acidic it can actually break down the new fluid rapidly. Also by doing the pan drop on a regular basis it gives you a chance to inspect for any debris in the pan, filter or on the magnet. If you see anything more than a small amount it will allow you to get to a problem before catastrophic failure.(usually occurs around 3:00 am while snowing 7" per hour).


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## ljbev (Dec 17, 2001)

Usually loose nut behind the wheel kills tranny!!:yow!:


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## BREAULT69 (Jan 15, 2008)

Then there is gonna be alot bad trannies.


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## Clapper&Company (Jan 4, 2005)

I think the 204,500 had somethign to do to mine going out


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## streetfrog (Dec 9, 2007)

Also remember that in the radiator where the trans lines connect it does not flow threw a big container. The area that the fluid goes thru is actually only 1 mm thick. It is basically 2 paper towel tubes. 1 inside the other. so any contamination at all can easily get lodged/build up in that small space. 
The coolant runs thru the middle of that tube. Just a FYI. That is why it is important to flush the trans lines if nothing else. If it gets clogged then you can mess up the trans. 
If it is a high mileage ( 85k and up) and trans has never had maintenance then do not get it done. But if you have regularly done services then mileage does not matter. 
Also if you own a Dodge then there is a 1 way check valve that tends to clog up and you can cook the trans. Also do not let a Dodge sit in park and idle for an extended amount of time as the trans fluid will not circulate if in park. If you are going to let idle for an extended amount of time put trans in neutral.


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## derekbroerse (Mar 6, 2004)

Heat heat heat!! (most common)

Check out the chart posted in this thread...

http://www.plowsite.com/showthread.php?t=26538


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## TEX (Nov 24, 2003)

if you do a flush drop the pan too.....

1. FULL trans service yearly
2. Good synthetic ATF like amsoil will help a lot 
3. Trans temp gauge
4. Deep trans pan
5. Think when you drive........
6. If you have to rebuild put in a good valve body and torque converter



if you need a place to get any of this stuff let me know...i will always help out a fellow plowsite member.


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## Fordistough (Feb 14, 2005)

Definately knowing how to drive properly is what it is all about. Good mechanics make good drivers.


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## big bird (Nov 12, 2007)

Fordistough;499140 said:


> Definately knowing how to drive properly is what it is all about. Good mechanics make good drivers.


i have nothing to say this says it all


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## B&B (Nov 4, 2006)

big bird;499184 said:


> i have nothing to say this says it all


 And hence my first post...



B&B;495039 said:


> 1# killer...the driver.


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## Italiano67 (Feb 16, 2005)

I have seen alot of mechanics that I would not let sit in my truck let alone drive it. I am not a mechanic so I drive it in a manner that hopefully I dont have to fix it.


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## PLOWMAN45 (Jul 2, 2003)

driver heat lack of matience oh yeag rough shifting


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## bribrius (May 5, 2007)

not enough tranny fluid or not changing the fluid, or using something for fluid not meant to be in a transmission..
drag racing.
submerging them in salt water.
car accidents.
plowing snow in general. 
towing more than the tranny wants to tow.
putting the gas all the way down and spinning your tires evertime you take off from a stop sign. this doubles for people who think they should do twenty consecutive cookies.
driving in first gear on the interstate at sixty five.
mileage. if you dont drive the vehicle the tranny will last longer.
people who think the R means Really fast.


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## Chevyboy (Feb 3, 2008)

down shifting, dropping your transmission into 1 when your doing over 25. Check the fluid level too or you could also be in trouble!!!


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## SteveJ (Jan 30, 2008)

bribrius;508749 said:


> people who think the R means Really fast.


<img src=http://www.getsmileyface.com/new/animations/laugh.gif>


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## Unimount219 (Jan 9, 2008)

*Duh*

Usually when a Trans goes out its from the Heat, dogging it or no fluid. I manage a quick 
lube and when we do a trans flush/Pan drop when dont put **** to clean it out, the only thing that cleans your trans is new trans fluid. Personally if i had an old plow truck that has had a plow on it all its life and hasnt ever been changd i wouldnt mess with it, but if you have a newer 2000 or newer with under 100k then it would be ok. And if you are a true snowplower you should know how to check your trans fluids, Snowplowing = Mechanically inclided. So if your ever in indiana and want your trans flushed come see me


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