Automatic Transmission life

[SchizophrenicMC]

Autotragic transmissions break down more quickly than manuals in my experience. The GMC's lasted 75k before it died. Given, it was originally an AT&T work truck with a cage on the back for equipment, so it took a lot of wear. Still, that's not a lot of miles. My buddy's Rodeo has an automatic, which was rebuilt at 110k. My Pathfinder has a 5 speed that's grinding but still working at 211k.

 

Really, though, it depends on how you treat it. If it's used nicely, mostly highway miles, and it's maintained, it'll last longer than if it's beat on and used for 4x4ing often.

 

By force of preference, I like to stay away from Automatics. I feel numb in them, and they don't like to last as long.

[Firehawk]

I took her out this evening for some light wheeling~ I took the truck out to a big ass drainage basin that is about a mile from my house. I spent about an hour or so driving straight up the ditch-grade and then I would go back down. Well after about an hour or so I got out to eat a snack and killed the motor. When I got back in for the 1 mi drive home something was not the same. I was able to verify it was in 4x4 hi and low and at this point it was in $ hi but 2 things~ the engine did not want to rev above 2K RPM and it did not seem like the front and rear axles wanted to spin and by that I mean standing on the throttle and it would never go above 2K rpm and it was all of a sudden a slug.

 

Any ideas or am I missing something?

[1994SEV6]

I was able to verify it was in 4x4 hi and low and at this point it was in $ hi but 2 things~ the engine did not want to rev above 2K RPM and it did not seem like the front and rear axles wanted to spin and by that I mean standing on the throttle and it would never go above 2K rpm and it was all of a sudden a slug.

 

Any ideas or am I missing something?

Kinda confused by "it was in 4x4 hi and low". I have deciphered that "it was in 4hi". You said "2 things", but those two things sound the same. It wouldn't go above 2k RPM and it didn't want to move.

 

Relating this to possible transmission problems because you posted it here, it could be your clutches severely slipping, but this wouldn't affect your engine.

 

More likely causes would be sensors for your rev problem. Your MAF being dirty or not connected properly can make your engine do some weird things.

Very unlikely in your situation, but I experienced a similar problem today. My gas gauge was lying to me, and I ran out of gas today. Before the tank was bone dry, my engine would stutter and stumble every once in a while. This has happened to me before so I knew it was coming. I just made it to a friend's house, but I couldn't get it above 2kRPM going up a hill near his house.

[silverton]

if you were playing in the water, you could have gotten some sensors wet. but, I notice when I work my truck hard, the transmission will almost seem like it's in TWO gears. watch the "power mode" indicator light for flashes, it will tell you if the transmission has a trouble code.

 

Automatic's can and will last just as long as a five speed if properly maintained. Only thing is, auto's need to be taken better care of because they are much more sensitive.

[Firehawk]

Sorry if I was not clear last night, I had a few drinks once I got home. I was stating that I was able to verify that 4L and 4H both work just fine. But after I had been playing for a little bit that is when she did not want to go back up the hill and the motor would not go above 2K rpm.

 

Sooo I went out this morning and drove around the block. Everything is acting normal. So who knows maybe something got wet. To be honest I was scared that I had already broke something and went to bed fairly aggravated and anticipating a future "told you so" from my Dad lol.

 

One other thing I noticed is every so often the truck dances around about 200rpm (very little)trying to find an idle. However most times it is just fine. It never surges or anything like that so I have ruled out a vac leak b/c it comes and goes. I am going to try cleaning the idle air control motor and see what happens.

 

 

Also, this "power" light... It did flash every now and then but only if I was punching the throttle. What's it's function?

 

And by the way~ it was SOOOO much fun wheeling in that little truck. It's a blast to drive and I can't wait for more!

Edited January 23, 2012 by Firehawk

[Slartibartfast]

The power light is for the transmission's 'power mode.' The little switch it's on turns it from normal mode to power mode. There's also a little button under the gas pedal, so when you floor it, it goes into power mode, which essentially means it shifts later. It's a lot more fun to drive in power mode, though I don't imagine it helps fuel milage any. If the light's flashing steadily, that means the transmission is either broken or confused, and it's put itself in limp home mode. It'll have no power/acceleration until you turn it off for a bit and it resets. Doesn't explain why the engine wouldn't top 2k though. It's got a limp home mode as well, but I thought that was 3k.

 

Another guy recently had a similar issue after doing some doughnuts in the snow... perhaps it's the same thing. If it happens again, try disconnecting the negative battery lead for a few minutes, then reconnecting.

 

Does the oscillation happen when it's cold, or when it warms up, too? Mine wouldn't idle well (dipping and surging), and I never tracked the problem completely down, but messing with the intake and the wires to the MAF and TPS seemed to fix it. It'll still do it when it's really cold if I put it in gear before it's warmed up.

 

They are fun... gotta get mine out more... most action it's seen with me was a dirt road.

[adamzan]

From my 1995 owners manual it says if the transmission does this to turn the ignition off and wait 3 seconds and then turn it back on. This worked for me when mine did it. You'll know if it worked if the power light stops flashing.

[Firehawk]

Thanks a bunch for all the info guys. I am just glad something did not break my first time off the road I was really impressed at how the truck would just roll right through sloppy mud. And it only took 30 min to clean it all (90% of it) off.

[SchizophrenicMC]

I know, a lot of times, if you overwork a transmission, it'll go into limp mode. One time, I was showing off in the GMC, and I dropped it into first to burn out at a light. And it burned out alright. I put it in drive while I was moving, but it stayed in second until I got to the pizza place. When I started it back up, it shifted properly again.

 

If you got sensors wet, or you got the tranny too hot trying to climb stuff, you could put it into limp mode, as it tries to protect itself from further damage. As for the engine issue, that could also be water related, or because of mud. It could even be related to the tranny controller telling the engine controller to keep it easy for the tranny.

 

What Silverton said, though. You have to baby automatics. That's why I don't like them.

[Kingman]

I will say, the '87 3-speed Jatco L3N71Bs were about bomb proof. I tried and tried and tried to blow mine up, I thought it was failing at 250K but all it needed was a fluid change and a cooler. It was wrecked at 260K. I red line neutral-dropped that thing daily, probably overheated it a lot trying to get the tires to turn and burnout (guuuuttlessss), and slammed in to first to swing some corners. It would not give out and still shifted fine.

 

On the other end of the spectrum, I was in a buddy's '91 Foxbody with an automatic one night when he revved up to a Honda next to him, let the revs fall to about 2,000RPM and put it in drive. Boom, done. Car no move. A cop came along and pushed the car to a parking lot with his cruiser.

[1994SEV6]

LOL. Fords.

LOLOL. Mustangs.

LOLOLOL. Automatic Mustangs.

 

It sounds like those 3speeds were actually really good. I just don't understand why the automotive industry is moving towards more gears.

For each gear they add, the repair bill doubles!

[adamzan]

It`s for fuel economy.

[silverton]

What Silverton said, though. You have to baby automatics. That's why I don't like them.

 

You don't have to baby them, they just require more frequent maintenance than five speeds do.

[SchizophrenicMC]

It`s for fuel economy.

Exactly. Everything in cars today is for fuel economy. More gears, bland design, more complex computerized engines, expensive contoured materials, it's all for fuel economy. Ford got rid of the Crown Victoria because it didn't sell well because it got 15MPG.

 

The more gears you have, the more you can keep the engine in power band, and/or at an efficient RPM. Semis have 6 to 24 forward speeds, depending on their transmission design. This keeps the engine at its optimal power band for acceleration, and at its optimum RPM for cruising. So it's not surprising to see 6-speed gearboxes becoming common on cars. Chrysler has the whole 8-speed automatic that I hear breaks down even more frequently than other Chrysler trannies. (Dies On Day Guarantee Ends)

 

You don't have to baby them, they just require more frequent maintenance than five speeds do.

Baby, frequently maintain, it's all the same when we're talking about trucks we throw at the roughest conditions one can reasonably expect of a vehicle. It's supposed to be robust, and capable of handling severe conditions. Automatics aren't historically great at this.

[Kingman]

Ford got rid of the Crown Victoria because it didn't sell well because it got 15MPG.

 

If you're only getting 15MPG out of one then there's something seriously wrong, or driving it like a mad man all the time (cop). They get on average 21-24MPG when driven like a normal car. That was one of the best chassis Ford ever produced, just too bad it was so outdated that mainly mass fleet companies bought them. Good power, fuel economy, reliable, and didn't handle that bad for such a big car that's super comfortable.

[1994SEV6]

a big car that's super comfortable.

that's really important when you're sitting in the back!

 

I didn't mean like "jeez, why would they EVER add more gears?! It's so stupid!" I meant like...jeez, new 8-speed transmissions when 3-speeds were the best you could get.

I understand the whole power band or efficiency band thing. It seems like a big price to pay just to save a bit of gas. It didn't seem to benefit our Nissans anyway.

I'm always thinking about that Chrysler 8speed. I was thinking about it when I typed that post. So ridiculous. It might always be in the desired power band, but it's ALWAYS shifting. And, you guessed it, shifting is the most harmful thing to an auto trans. Kinda funny how that works.

[Kingman]

Chrysler isn't the first with an 8-speed, Toyota beat them to it with one of their Lexus models last year or a year before I believe.

 

That many gears is entirely ridiculous, 6 is plenty and does serve a purpose.

 

There's quite a few vehicles out there that the performance version of ends up using an older 5-speed because the newer 6-speeds aren't strong enough to handle more power.

[Slartibartfast]

I've been looking at CVT/IVT/mechanical torque converters lately... it's a great idea, rather than having a crazy number of gears where each has its own butter zone, it's basically made of butter. The execution just tends to be somewhat lacking. Half of them rely on belts and metal balls and special fluids, and the others use one way clutches... which means no engine braking.

 

I dunno, maybe we should just go electric. 100% torque at 0RPM. Just gotta figure out that battery thing...

[Tungsten]

The best thing to do for maximum efficiency is to have a gasoline/electric hybrid motor. The electric motor can assist with taking off and the gasoline engine can power the vehicle down the road. Of course battery power, regeneration, and cooling are issues then.

[Firehawk]

I've been looking at CVT/IVT/mechanical torque converters lately...

 

 

My 2011 Chevy 2500's 6 speed and torque converter are pretty high tech as well. And no, not the Allison, it's a 6L90E (If I remember correctly). 1st is a granny, then a somewhat normal 4 speed in the middle of a 5th and 6th overdrive gears. Ya, cool enough but I noticed when I am pulling a trailer or a large load the trans will actually slip the torque converter to increase RPM but not downshift. The first time it did it I was like wow, that's slick. And yes I know torque converters are designed per the car they are in~ for example a slow 3 speed automatic Neon trans only locks the torque converter in 3rd gear.

 

anyway~

Edited January 24, 2012 by Firehawk

[SchizophrenicMC]

Chrysler isn't the first with an 8-speed, Toyota beat them to it with one of their Lexus models last year or a year before I believe.

 

That many gears is entirely ridiculous, 6 is plenty and does serve a purpose.

 

There's quite a few vehicles out there that the performance version of ends up using an older 5-speed because the newer 6-speeds aren't strong enough to handle more power.

Yeah, but Chrysler's the ones shouting it all the time.

 

Too many gears in a small case, and they'll break. 6 is about as high as a passenger car needs.

 

I've been looking at CVT/IVT/mechanical torque converters lately... it's a great idea, rather than having a crazy number of gears where each has its own butter zone, it's basically made of butter. The execution just tends to be somewhat lacking. Half of them rely on belts and metal balls and special fluids, and the others use one way clutches... which means no engine braking.

 

I dunno, maybe we should just go electric. 100% torque at 0RPM. Just gotta figure out that battery thing...

 

The problem with CVTs is energy losses to the torque converter. A fluid coupling will increase frictional losses. If coupled to a computer-actuated clutch, however, the problem is largely mitigated. The problem is, electronic clutches are more expensive than fluid torque converters.

 

If we go electric, there's an issue aside from batteries. The EV is the poster child of saving the environment, but electricity production produces more carbon emissions per energy unit than a midsize car engine generating the same unit of energy. So, if gasoline-based energy production drops and electrical production rises proportionally, emissions will also rise. This, on top of the wild monetary and environmental costs of batteries and their production.

 

The best thing to do for maximum efficiency is to have a gasoline/electric hybrid motor. The electric motor can assist with taking off and the gasoline engine can power the vehicle down the road. Of course battery power, regeneration, and cooling are issues then.

While electrics have superior 0-velocity torque, they require complex battery systems, which are heavy and environmentally unsafe to produce and dispose of, to say nothing of their poor reliability. Of course the last issue can be rectified through further research and development, but the materials required are as unsustainable as fossil fuels.

 

 

Electric vehicles rely on an inefficient set of energy conversions (Chemical -> Thermal -> Mechanical -> Electrical -> Mechanical, as opposed to Chemical -> Thermal & Mechanical) and use highly polluting methods of generating energy (Coal is the single worst source of carbon emissions, and accounts for 39% of US energy production). While it can be argued that more environmentally friendly energy infrastructure can be set in place, the problem stands that the technology for that is not here yet, despite continued work by scientists and engineers worldwide. So, for the time being, while I firmly believe development should continue in the field, it is an impractical, frankly harmful method of transportation to use electric passenger cars. Simply put, EVs are a way to sell merchandise. Everyone wants to save the world. No one doesn't want to do things for the good of the planet. So people hear "EVs are green" and they buy 12,000 Nissan Leafs, no matter what the actual effects are.

 

(Transportation refers to all road and non-road transportation)

[Firehawk]

^ I like it.

 

 

I consider any joke electric vehicle to be a coal powered car.

 

 

We laughed a local proud Volt owner away from a local Sat night show and shine as well. He pulled up, backed in and proceeded to pop the hood. We giggle, he takes off. : )

Edited January 24, 2012 by Firehawk

[Tungsten]

SchizophrenicMC, I agree 100%. Electric vehicles, at least right now, are nothing short of being a complete joke. You can sell anything to people with "feel good" stickers on it.

[silverton]

I drove a friends VQ35 CVT Altima. That thing was a blast. It almost felt like a turbo car with the way it accelerated, and just kept accelerating.

[Tungsten]

CVTs are great but their use is very limited, partly because they are belt driven. There is a special CVT with a non-belt toroidal design currently in the works by Nissan.