Why aren't gears hardened through a heating process to prevent them from stripping out like this? Too expensive?
Why aren't gears hardened through a heating process to prevent them from stripping out like this? Too expensive?
Adrian Clark
David Gomez
Yep, too expensive. They expect proper tranny maintenance to prevent such things
Jacob Flores
Planned obsolescence.
If it's built too well, you'll never buy a new car again.
Angel Baker
Most lower range gears are.
It's pointless on higher gears and overdrive because there's just no real reason to when the shit economy engine only makes 100ftlbs torque
Jason Peterson
cuz you give gears that cyro treatment if you really care about longevity and strength
Benjamin Miller
If they're hard they're less able to cope with shock.
Connor Green
>lel why cant they make them not brake
They were made properly, op. The problem is you're not using that trans for what it's intended to do.
Bentley Perry
From what I know the hardening process also causes steel to become more brittle, which is actually what your picture is showing.
Hardness is only good for surface wear, but when it comes to impact/fracture resistance, it is brittleness that governs. I think it relates to thermal-induced tension in the surface of the steel which happens when it is rapidly cooled (i.e. quenching). But I could be wrong on that.
Christopher Torres
these anons got it
Camden Young
They are hardened, but not through a heating process. The outside of the gear is hardened through a process called carburizing or case hardening. Carbon atoms diffuse to interstitial sites between iron atoms and "lock" the planes of iron and put the crystal structure in compression. The problem isn't that the gears weren't hard enough, you just weren't using the transmission properly.
t. mechanical engineering student currently studying materials science & engineering
Lucas Sullivan
mong
Lucas Collins
What people don't realize is the harder you make something the more brittle it becomes. Glass is one of the hardest materials around. It's far from the toughest and most durable
Aiden Jones
Nissan transmissions are just shit.
Brandon Gutierrez
Err doesn't carburising specifically use a heating process?
Jack Cruz
Manual cucks BTFO
Jayden Green
This is correct. You also have more expensive alloys to make a better transmission, but no retard average Joe bothers to check what metal was used when he buys a car so you end up buying bullshit metal
Charles Long
Just get a sequential straight-cut gear box and be done with it.
Lincoln Wood
Honestly this, straight cut gears can handle a lot more force
Logan Hughes
>WHIRRRRRRRRRRRRRRR
Daniel Robinson
i was told that cars dont use straight cut gears because they are loud as fuck
Josiah Garcia
Helical gears are just as strong. What you're looking for is a dogbox.
Dylan Baker
It's heated but not to the extent of heat treatment.
Logan Williams
Straight cut gears can't handle as much force as helical gears because they have less mechanical engagement than helicals.
Logan Kelly
>t. mechanical engineering student currently studying materials science & engineering
Can you recommend any books about materials science? I'm looking for a reference for identifying materials and their properties.
David Richardson
>can you recommend me a book on [incredibly wide subject]
lmgtfy.com
Lincoln Young
transmission gears are typically carburized (usually 8620 alloy steel), and for a reason
carburization gives an extremely hard exterior, roughly low 60's on the HRC scale, or about equivalent to a ball bearing. this allows the gears to go fucking.for.ever. without getting the least bit warn out. the root of the gear teeth is still softish, i.e. tough, which means the tear are less likely to shatter from being brittle. this is because carburization only hardens to a depth of around ~0.060"
some times gears are made of a through hardening alloy (4340, 4140, 300M) and oil quenched and tempered for a through hardness. this issue with this is that as the gear gets harder, it also gets more brittle. You can only Q&T 4340 up to mid 50's on the HRC scale, and the result is a very brittle gear tooth that can shatter. if you want the toughest possible gear, you might only harden to around HRC 45, which will leave you with a stronger gear than a carburized 8620 gear, but it is softer and thus it wont last as long as the carburized gear
t. - i made a little gear reduction transaxle in college for my schools SAE baja team
pic is of some gears i made for the transaxle. they were 4340 quenched and tempered to HRC 45. we wanted max strenght and didnt give 2 shits about longevity since the car would be cut up and scrapped before it ever had a thousand miles on it
Ryan Morris
>can you recomment me any good restaurants in this city
HURR DURR GOOGLE RESTAURANTS IN THIS CITY
Blake Stewart
this is the one we're using
abmpk.files.wordpress.com
Owen Brown
>HURR DURR GOOGLE RESTAURANTS IN THIS CITY
lmgtfy.com
Bentley Baker
Why not just make all the gears out of diamond?
Problem solved
Christian Hill
true, diamond is the hardest metal after all
Hudson Hill
excuse me, the hardest metal is actually Death Grips
Sebastian Martinez
You say it like that's a bad thing
Chase Price
You see shit like this in military grade stuff though. Meant to carry tons and last for a hundred years. Hell, stuff from Vietnam and older are still fine and working.
Angel Walker
"military grade" is a bullshit thing and doesnt exist except for in electronics, where it is actually not the highest grade and mostly refers to temperatures it can withstand and still work normally
i bet you have some bullshit cucc trucc you bought because the commercial said MILITARY GRADE ALUMINUM and then immediately took it to get squatted and have its diff welded solid
Xavier Martin
Thanks. I won't read it all but I'll find appendix B and D useful.
Easton Bailey
"military grade" actually means the cheapest and fastest
Jackson Foster
And built by the lowest bidder.
Benjamin Torres
>mfw idiots like OP don't know shit about metallurgy basics like brittleness or ductility but still feel like they need to make uninformed comments as such like they're the fucking authority on it
You don't know shit OP, shut the fuck up
Eli Walker
A flexy case can be just as much, if not more of a problem, than the gears themselves. Applied torque drives the gears apart, if the case isn't strong enough to keep the shafts together you get the same result.
Jace Nelson
Check out machinery's handbook 30th edition
Nolan Edwards
Not him, but you're a cock
Matthew Butler
Helical geare are stronger, however, straight cut gears reduce friction losses.
Cooper Evans
Brittle failure doesn't look like paste. Peices snap off, but don't deform much. The remains of those gears are definitely wider than they should be, so the picture shows deformation and thus not a brittle failure.
Henry Rivera
Because diamond is heavy as fuck. one gram of diamond weighs something like 15 grams.
Mason Reyes
hmmmmmmmmmmmmmmmmmmmm
Connor Flores
its an old joke you dip
Kayden Bailey