How do people grind gears?

[oilcandave]

...had an old pickup when I was young that had to be double clutched to shift reliably.

..since someone brought up motorcycles..I love when the young on the crotch rockets try to show off and miss the shift...with the accompanying redline in neutral...never did that when I rode ..

 

[skyactiv]

I tend to drive stick cars abusively. I have the money to fix it if something happens and I don't show off.


I just sold a 2018 Hyundai Elantra Sport with a stick. That car is very easy to float gears and go from 1st to 3rd quickly without grinding. My wife's 2015 Audi A4 quattro is a 6 speed manual and you cant get away with going to redline in 1st and skipping into 3rd quickly without grinding, so I pretty much gave up doing that on the Audi. I had a 2013 GTI that was just like the Audi. My wife had a Mazda3 with a stick and I don't remember that car grinding it's gears.

I had an 07' WRX with a 5 speed before the VW. The WRX felt like the transmission was going to grenade or spit out from the car when I ran it at the drag strip.

 

[JimPghPA]

Another old saying is "While you are at it, grind me a pound."

 

[supton]

Hadn’t driven a stick in a few years, find that I am letting the clutch out toon soon going into second sometimes. The syncro has always been kinda wonky though so I shift into second a bit slower than other gears, so that does not help.

 

[2005jettatdi]

Try driving a Model A without grinding gears. One of the reasons I keep my Jetta going is because I prefer to drive a manual. For me it shifts like an automatic because I usually don't even think about it, it just happens.

 

[Rhymingmechanic]

I learned to drive in a Dodge pickup with a granny-low 4-speed (and a Farmall H--pretty sure those gears were easy to grind). I don't know the "how" of it, but I think the pickup ground fairly often going into reverse, and I want to say first as well. I also drove a 3-speed Duster for several years. I can't specifically remember grinding that trans, but I did surprise myself once trying to shift into fourth gear.

 

[Jetronic]

I never have been able to figure out how people grind gears when shifting improperly since I thought the synchronizers were designed to not allow the gear to engage if the gear speeds aren't matched up, but somehow some people still grind when shifting.

There have been a few times I have accidentally attempted to shift without the clutch fully disengaged, once or twice I have even accidentally tried to engage 1st gear while stopped without using the clutch. Never any grinding though, it just wouldn't go into gear and I quickly realized my mistake and pushed the clutch with no damage done and no grinding.

The only thing I can think of is maybe some people try to force it into gear without the clutch fully disengaged they may grind it, but other than that I just don't understand how people do it and I wouldn't know about forcing it into gear since I never did that.

If someone could explain to me how people manage to grind I would appreciate it since that is something I am genuinely curious about. Thanks in advance!

That's exactly what you hear, the synchronizers... the shift sleeve needs to be slid over the synchronizer hub onto the blocker ring and the dog teeth on the gear.They are essentially small straight cut gear teeth. well, nearly straight cut, they'rer a bit tapered so the shift sleeve will stay on under power.

If you can't get onto the blocker ring there won't be any grinding, but if you do and the synchronizer didn't stop the gears yet it will grind on the gear dog teeth.

 

[DGXR]

In a synchromesh you can't grind gears since the gears are in constant mesh. The teeth on the synchros will make a grinding noise due to careless shifting or wear. An unsynchronized gear, frequently the reverse gear, may grind if operated carelessly.

So all those times I accidentally let out the clutch before the gear was fully engaged, those were the dog teeth grinding? I could have sworn that was the gears.

 

[vavavroom]

So all those times I accidentally let out the clutch before the gear was fully engaged, those were the dog teeth grinding? I could have sworn that was the gears.

Correct. The dog teeth make the noise and can get chipped. The gears are in constant mesh - other than is the case with non-non+synchronized gears (commonly reverse and rarely 1st gear).

 

[UG_Passat]

The Nissan 350Z gearbox usually grinded going from 2nd to 3rd gear. It's a defining performance characteristic of that car

 

[wemay]

Some manual transmissions are better than others. There are some that no matter how talented the driver is they will eventually grind a gear here and there. I'll refrain from calling out OEMs.

 

[Motu]

So all those times I accidentally let out the clutch before the gear was fully engaged, those were the dog teeth grinding? I could have sworn that was the gears.

The only time you will actually shift gears is in reverse. Even in a truck crash box, and motorcycles, you are shifting dogs. A syncro box has a syncro or baulk ring between the dogs to slow them down to speed.

 

[vavavroom]

The misunderstanding is due to "gear" having two meanings in English. It means 1st, 2nd, 3rd, etc gear and it refers to an actual gear wheel. Each gear is just a combination of gear wheels.

 

[Dinoburner]

There are constant mesh transmissions and sliding gear transmissions like Muncie and Saginaw either of which can occasionally get by the synchros. One method to get into reverse is to shift into into second or high then quickly into reverse. Another old saying is they are going to make them out of rubber next year.

 

[Jetronic]

So all those times I accidentally let out the clutch before the gear was fully engaged, those were the dog teeth grinding? I could have sworn that was the gears.

Reverse gear sometimes has straight-cut unsynchronised gears that are not constant mesh. Usually the smaller boxes with no lockout for reverse. There you can grind the gears if the car isn't stationary. Other than that it's the dog teeth you hear as the gears are constantly meshed

 

[aquariuscsm]

I’ve driven a few Mustang GT’s that will grind the 1>2 gear shift if you shift too fast. These were the Chinese 6 speed transmissions. I’ve never had a Tremec T5 grind the 1>2 shift.

 

[Oliveoil2]

I like using a manual trans. Try to use three fingers to shift. Never pushing the syncro’s, giving extra time on every shift.

 

[Avery4]

I like using a manual trans. Try to use three fingers to shift. Never pushing the syncro’s, giving extra time on every shift.

That's what I do, I only use light pressure when shifting and let the next gear engage when its ready to. Perhaps that's the reason I have never managed to grind, even the times I didn't use the clutch properly. From my understanding if enough force is used it's possible to push your way past the synchros and force the gear to engage (or attempt to) even if the speeds aren't yet matched. Maybe that's how people manage to grind modern synchronized transmissions

 

[aquariuscsm]

I hold the shifter like an egg in my palm.

I think when you get a grind, it's the hydraulics experiencing a hiccup. The only gear I've ever managed to grind is 3rd, when I'm not paying attention to matching the clutch pedal timing.

 

[The_Jeff]

I used to have an S-10 pickup.... Even while stopped, I had to wait several seconds after pressing in the clutch before I could shift into Reverse. I quickly got used to and and I have to consciously think about it to avoid doing it now.

My dodge dakota owners manual stated to do exactly this.

When I was 16 I thought I was Mr. Cool "speed-shifting" my mom's 323 transmission. It was basically putting pressure on the shifter towards neutral and stomping on the clutch. As the clutch started to disengage it would go for neutral then inertia of my moving the shifter would slam it into the next gear, presumably ripping the synchros pretty well in the process.

Joke was on me though because I inherited the car a few years later and it died a clutch or transmission death.