Gearboxes
Images are sometimes not shown due to bandwidth/network limitations. Refreshing the page usually helps.
You are currently reading a thread in /o/ - Auto
You are currently reading a thread in /o/ - Auto
Why is it that transmissions do not need to have their own dedicated cooling system? They get hot too, don't they?
>>13995739
not hot enough to matter, apparently.
It's a different kind of heat.
race cars and some extremely high performance street cars have transmission coolers. they're not usually necessary because no combustion is taking place in the transmission obviously. friction is pretty much the only major source of heat. that and heat transferred from the engine.
![Z-tune-355[1].jpg](https://i.imgur.com/2Dqx3Yr.jpg "Z-tune-355[1].jpg")
>not having a transmission and differential oil cooleres
what a pleb
>>13995739
some do brah
>>13995755
how would you know if your diff or trans was overheating and that you needed a diff or trans cooler? this seems unnecessary.
>>13995761
Your diff is overheating if you should be putting down power through a corner and you're not. Your gearbox is overheating.. well you'll feel it. A gearbox is just all metal moving parts, the danger is that it gets so hot the gears become soft, the teeth no longer match up correctly and shit gets bad.
>>13995763
the gears will literally becomes soft? I find that hard to believe. steel melts at almost 3000 degrees F
Heavy trucks and shit all have them. Diff temp Guages on the dash too. Often the autos will just run heat exchangers with the engine coolant, which is all good till the auto fucks out and overheats your engine.
In cars that have the transmission attached directly to the engine (most cars), does the heat from the transmission get partially stolen by the engine's cooling system?
>>13995768
Maybe it's filled with jet fuel and not oil
>>13995749
I guess my Lincoln Town Car is an extremely high performance street car then.
>>13995774
yeah my bad I read some more and apparently a lot of cars have them
>>13995774
No. It's just an automatic. They all have fluid coolers.
I have a transmission and and oil cooler in my car.
Diff cooler next.
I have no reason to get these things, I just trick myself into thinking I do.
Because racecar and my experience watercooling computers.
>>13995739
Some do. In most consumer cars, they radiate enough heat away from the transmission body to stay at optimal operating temperature, so adding a transmission cooler means you'd lower that temperatures below the optimal point. Same applies to differentials - if you think about it, both are boxes of well-oiled metals clashing together in a controlled manner. It's friction between those metal that causes this heat.
Now, if heavy duty applications, such as very heavy trucks, or constantly accelerating racecars, you need a transmission cooler (and probably a diff cooler too). The aount of heat generated is simply too big. An automatic gearbox designed for dragracing (for example a 2 speed Powerglide) is designed to slip for example,creating massive heat, which you need to get rid of. If not, the transmission fluid/differential fluid/oil/whatever stops doing it's job (because it's out of it's temperature range), and stops lubricating the metal spinning inside the gearbox/diff - which can really ruin your day.
Also, keep in mind this wear increases exponentially the higher the operating temperature becomes. 5 degrees too hot doesn't do a lot of damages - but 10-20 quickly will, and 40-50 can become fatal within hours if not minutes of service life.
are there pumps that push trans fluid through the radiators or something? I thought that manual trans just used a bath of oil to lubricate and cool, no pumps.
>>13995782
>In most consumer cars, they radiate enough heat away from the transmission body to stay at optimal operating temperature, so adding a transmission cooler means you'd lower that temperatures below the optimal point
so you're saying my miata doesn't need a trans and diff cooler?
>>13995749
Heavy duty trucks etc. also need them.
>>13995761
Well, you should put a cheap temperature sensor in both if you're worried(most consumer cars aren't at risk). If the temperature gets too hot during regular use, you need a cooler. Surefire way to find out without a temp sensor is too smell the ATF - you'll notice when you've cooked your transmission, trust me.
>>13995768
Gears don't become soft - it's just that they deteriorate very quickly when not properly lubricated at several thousand RPM.
>>13995771
There's usually a heat exchanger that exchanges transmission heat (either via oil or coolant) into the regular engine coolant, which then gets dissipated via the radiator. Of course this simplifies packaging, but a dedicated transmission/diff cooler is better if you're pushing your car hard.
>>13995790
Road use, no modifications? No.
Track use? Probably. Install a temp sensor to be sure.
LSD? High chance of needing a dedicating diff cooler.
Significant engine mods? Probably need both.
>>13995768
Which is why a gearbox's heat only matters in extreme cases. Shit's not gonna melt, but weakness in the steel caused by extreme heat could compromise the gears.
Like I said, a transmission isn't really anything more than a bunch of steel parts being powered externally, the only thing heat is going to do is compromise the material.
>>13995739
Maybe because there arent fucking thousands of explosions heating it up?
>>13995755
>Too much hot & cold
>everything explodes due to basic physics.
>>13995783
Yeah my car has this, it's an auto toyota
>>13995749
Police cars have transmission coolers too.
![1365639033236[1].jpg](https://i.imgur.com/Q6Bo32R.jpg "1365639033236[1].jpg")
>>13996487
the fuck are you talking about
