Synchronizer Operation Explained

Manual Transmission Synchronizer Operation Explained.

[@5CGQ]

What most people don't appreciate is that "grinding gears" isn't damaging the actual gears that transmit power, but the dog teeth on the synchro system.

[@DrivelineMaster]

You are absolutely correct.

[@dangeary2134]

Makes me appreciate that big truck transmissions generally do not have synchronized gearsets. I had to rebuild an entire transmission when someone had broken the main output shaft in one. No books, no drawings, nothing but brute competence. I will say, the way that they are made with dual or triple countershafts, the design is ingenious. The input and output shaft are only connected by a pilot bearing. The fact that the main output was snapped into two pieces, and the transmission didn’t fly apart is testament to the designer! The countershafts held the gears in their proper location, even though the shaft was toast! No synchronization there, just a good gear matching hand was required!

[@mikekokomomike]

I have a Kawasaki motorcycle and the factory service manual chapter on repairing the transmission has one line about " paying attention to the mating dogs ". Made me chuckle.

[@josephschaefer9163]

Not if you have old stuff with slider gears

[@josephschaefer9163]

@Franky997 grinding gears on old stuff like '47 chevy, farmall tractors, or cub cadet lawn mowers does damage the actual gear teeth. The whole gear slides to engage

[@Danielagostinho21]

Using a strobe light to see gears at speed mesh, Brilliant!

[@mathewshackelford8037]

Works just like a timing light

[@anthonygonzalez-oit9299]

This was really well explained. The video at the end really capped it off and pulled it all together for me. Thanks.

[@ComMando9100]

I wish teachers at school would teach the same way. Amazing video with lots of different presentations, I don't think this could be explained any better than this!!!

[@sarthak_18]

Really sir you said true thing

[@rogergummer5173]

Given the hard job, its a reasonably good explanation.

[@mikes9939]

Would be good to explain that the synchro ring is made of brass hence it's gold color. Brass is softer and is sacrificial meaning it will eventually wear out and need replacement. Brass is the perfect companion metal to press against the hard steel gear and do no damage to it as it tries to either speed it up or slow it down so the the synchro hub can slide over and complete the lockup. It's important to remember that the synchronizer assembly must adjust the speed of the entire cluster gear and input shaft including clutch disc in order to perform the lockup into the selected gear. Quite a task and shows why you must have clean clutch release so that the disc is completely free to rotate. This is a very good video, especially with the gear train illuminated with the strobe light to show what happens.

[@DrivelineMaster]

Thank you for your good comments. You are correct. One note. although these blocker rings are brass there are other blocker rings made of other materials and sometimes either lined with a friction material similar to brake lining and others that use a bi-metal design with a sintered metal inner cone that is soft with a high coefficient friction. I will consider a followup video with this additional information.

[@shaggydogg630]

We had some Mustangs rings made of paper! Replaced many.

[@Kevin-mx1vi]

​@@Franky997Can confirm that because some years ago I worked for a company that made synchromesh rings for many of the major European car manufacturers. Selector forks were also made from phosphor bronze, but of a different grade.

[@jptrainor]

Best and only video of a synchronizer in live operation that I've seen.

[@maneki9neko]

This is terrific. Details like the back cut on the engagement teeth on both the synchronizer sleeve and the speed gear, are new to me. This is shown under magnification at 2:15, and is easily missed when you have the parts in your hand. This back cut is what holds the two parts together under load, and prevents the car from popping out of gear. When an older transmission pops out of gear people will tell you with authority and confidence: 'oh, the synchronizer rings are bad'. But the synchro rings have little to do with this function. However when this tiny back cut, on on the engagement teeth of the speed gear or the synchronizer sleeve is worn away, there is nothing left to hold speed gear and sleeve together. In this case a new set of synchro rings will do nothing to fix the problem. And that is very much worth knowing.

[@DrivelineMaster]

Thank you for your comments. Please note that the back cut is not present on all synchronizer sleeves and gears. I see it missing mostly on older transmission designs. There are several reasons why a transmission will jump out of gear and worn out back cut is one of them. Normally what happens is the oil is not changed when it should be and or the driver is rough on the transmission and the blocker rings start to wear causing grinding (gear clash) which in turn chews up the clutching teeth on the gear and on the sleeve which wears away the back cut. It's often a domino effect.

[@getplaning]

I have overhauled countless gearboxes, measuring gaps and replacing parts, but this is the best explanation of how a gearbox works that I have ever seen.

[@DrivelineMaster]

Thanks for the compliment.

[@OverlyCuriousEngineer]

One of the best videos i have ever watched about synchro mechanism. Incredible presentation.

[@DrivelineMaster]

Thank you

[@maneki9neko]

Yes. He really has all the fine details down. Gear boxes for Spec Miata racing are rebuilt all the time. However the re-builds tend to have problems. If a rebuilder replaces the bearings, the brass synchro rings, and the seals then the gearbox will shift into gears easily and the box will hold oil, but will it stay in gear? Apparently if the back-cut (2:15 in the video) on the engagement teeth between speed gear and synchro sleeve are worn, these parts need to be replaced too. Someone who is simply installing a 'rebuild kit' will miss this.

[@spacetrace7021]

The ability or willing to show what you explaining just earned you a subscriber.

[@xavieraxiak6866]

As the sleeve moves towards the speed gear, the keys weakly push the blocking ring ahead until the conical friction surfaces make contact. The resulting frictional torque rotates the blocking ring so that it's teeth are 1/4 tooth pitch misaligned with the sleeve teeth which causes contact of the teethes' angled surfaces. This is called "energizing". As well as causing the blocking teeth to block the sleeve, the sleeve can now apply a strong force to the blocking ring via the tooth contact, increasing friction and synchronizing torque.

[@abhijeetchilwirwar722]

A great video , actually had doubts about the internal shafts used and the sleeve and gear engagement but this video had it all covered

[@maxwelld3753]

Never understood how they worked until I watched this. Very well done.

[@jerryscared]

Great video! Wonderful explanation. I especially appreciated the summary in the beginning of the three functions of the synchronizer.

[@NickGiamattiKeyWest]

Fantastic presentation!....Great technical detail & functional explanation! Strobe light visual on the Rotating System really brought-it-all- together! Thank you!

[@Kimbeattie]

Great video and the strobe light showing the operation was brilliant thanks from Canada

[@adamapostolos781]

Thank you for explaining & animating, this technology is becoming clearer, thank you

[@chimeragaming56]

really nothing beats a good explanation and some actual footage or hands on with my actual hands. ty for this.

[@LEDRavecom]

Wow, using the strobe light to show synchronizer at work is brilliant! Thank you!

[@frankcastle8349]

Thanks for the video! An excellent explaination,best on YT for gears.

[@kengarcia1461]

Really good, well explained and easy to understand demonstration. Thanks for making and sharing this video

[@aniruthdinesh9156]

Awesome Presentation, now I understand how this really works!

[@chadportenga7858]

Thank you! The demonstration of the synchro in action at 7:00 helps it all make sense. (The first part of the video is the nitty gritty of what makes it work. The demo shows it in action.)

[@pablogarciavasquez6637]

¡EXCELLENT MASTER CLASS AND GREAT TEACHER GREETINGS FROM LIMA PERU!

[@georgespangler1517]

Thanks,,,great informative vedio of the operations

[@Tedminat0r]

Brilliant idea with the strobe light. Thanks!

[@doublebass3858]

very good explanation. The only video I found that explains the synchronizing gear in great detail

[@DrivelineMaster]

I'm glad this worked out for you.

[@elora2525]

The best video for ASE, I watched this video 2 times before the test and still didn't pay enough attention. This video need to be watch 3 times for ASE manual transmission test

[@gsheverything_2716]

Why the test, if you don't mind me asking???

[@OwensGarage]

Excellent video, thank you. You just filled up another small gap in my mechanical knowledge.

[@scattkiwiman]

thank you for showing this !

[@diegorodriguez-lk8of]

Great fucken video don't give up you'll be up to 1 million subscribers soon. Best of luck and thanks for making things clear and simple to understand

[@lovesjw]

Applause! Real gentlemen applaud this good video!

[@vusindlovu8897]

Simply beautiful 👌

[@jacobwarrington1904]

Thanks for the video! Helped me study.

[@jabberwockytdi8901]

Still the best video on KZbin on this subject

[@DrivelineMaster]

Thank you. This is one of my top videos.

[@DORVALFAGUNDES]

Drivemaster, you're the best Master. My language is Portuguese, but I didn't understand the Brazilian videos and I understood your video. I didn't understand how the synchronized ring works but thank for you, I understand now.

[@DrivelineMaster]

Your Welcome

[@johnpower8356]

Great with strobe, I had a 1958 Mack truck when I was young no syncro’s man you had to shift just right, you get used to it. Great video

[@katojeremiahcsfg4274]

Liked the way you tried everything to make us get the idea, thanks

[@oscarchitsa6548]

Well explained bravo

[@jimc6481]

Thanks you, excellent video and explanation.

[@dalekrinke2674]

Very good explanation of this mechanism. Thank you a bunch for your time and experience! 👍👍

[@Bushybowl]

Excellent job on the video, structured and explained perfectly and pleasure watching

[@ayiideng5857]

thank you for its very explained and helpful

[@SS-U23]

awesome explanation Thank you

[@SteveFloresCoach]

This video was great!!! Thank you for it.

[@edgalaxie]

Excellent video!

[@franzjones179]

⭐fantastic video, thanks..!

[@spiritspride46]

Good video. Thank you.

[@nickayivor8432]

Thanks for sharing what you know with us brilliant video tutorial amazing From Nick Ayivor from London England UK 🇬🇧

[@cncn9631]

Its Amazing teach Video I Ever Seen. Good Jobs

[@raymondjames9734]

i want to use this to make a fixed gear / free wheel bicycle hub! never understood this before thank you!

[@maxenielsen]

Marvelous! Thank you so much!

[@hagebunshin]

Thank you for this!

[@mrbigheart]

thank you, sir. this is highly useful!!

[@keitharoo1962]

Wow, did I just learn something today!!!! Thanks!!!

[@BugCrush3r]

excellent description of the synchronizer but I wish you talked a bit more about the locking keys and springs and the purpose they serve

[@DrivelineMaster]

They are not locking keys. They are synchronizer keys. They transfer the force between the sleeve to the blocker ring.

[@jafersadique7492]

Very informative 👍👍

[@stimpsonjcat67]

Damn fine job on the strobe use!

[@utkarshkushwah8800]

Thanks for the such a nice explanatary video...

[@elwoodgalapagos1846]

gotta love the reverb on the voice

[@JohnSmith-ok9sn]

Exceptional video. Thank You!

[@DrivelineMaster]

John Smith from Plymouth, MI?

[@EquipmentEngineering]

Magnificent

[@Limeayy]

Woo, this time Manual Transmissions. If i literally had an instructor that taught like this I think it'd go into my head alot easier :P

[@Engineerboy100]

Wow!!!! That was awesome 👌 thanks you so much for posting.

[@fjs1111]

You did phenomenal work putting this together and your explanations. Learned a few things.

[@DrivelineMaster]

Glad you enjoyed it and found it of value.

[@PS_on_youtube]

Very nicely explained!

[@kalef1234]

That strobe demo was great

[@larrydykes7643]

Somebody needed to show this video to my old '67 VW bug.

[@ericbanks6644]

Fantastic video. Thanks!

[@billglenn10]

Excellent video and explanation of how this works... Thank you...

[@RC-Heli835]

That is so cool to see it working like it should. My KW T800 has an 8LL and its synchroniser has been very noisy since the heat exchanger went bad and got water into the transmission.

[@DrivelineMaster]

Try Changing the oil and put Redline Manual Transmission Fluid (MTF) in it. This stuff does wonders sometimes.

[@RC-Heli835]

@@DrivelineMaster I just have changed the incorrect 90 wt for 50 wt motor oil. That by its self worked wonders. It made it possible to where the gear shift would actually move the gears in and out. Before that I could take it out of gear and it would stay in gear. It did that one morning until the oil got warm. I ran it all day, came in and drained that 90 wt while hot and its been better ever since. Everything but the synchroniser. So mine is not slowing the gear down when all that noise is going on? I wonder if the air shifter could be sticky somehow?

[@DrivelineMaster]

Unless the manufacture says you can use motor oil instead of GL4 or GL5 gear oil I wouldn't leave the 50st motor oil in your transmission. 90wt gear oil is not the same as it would be if it was 90wt motor oil. The way they measure thickness for gear oil is different than motor oil. Once again I would recommend the Redline MFT. I know it cost more but it is worth it. Unless your transmission was designed to work with motor oil (like some honda's) you will end up damaging your transmission and costing you more $$$ in the long run.

[@RC-Heli835]

@@DrivelineMaster It calls for 50 wt engine oil. Granted Synthetic would be better but we just had a cracked head replaced at 6,389.00 on the truck and now the compressor has blown apart on the other truck leaving us stuck with a core fee. Cat wants 1,500.00 just for the core fee alone. Fleet Pride got us a refurbished for little over a grand and no core charge.

[@DrivelineMaster]

As long as the factory specification is 50wt engine oil then that is what you should use and have confidence that you won't cause any damage. This is the first trans that I know about that uses 50 wt straight motor oil.

[@akashmore9127]

Thanks very well explained 🙏🙏🙏

[@abdullahmohammed2955]

Amazing video thanks alot hope u r having a beautiful life ❤

[@charleskutrufis9612]

Thank You for this video. Very informative.

[@deepsinghania6496]

This video is clear my concept

[@MrsTiaRani]

awesome video, very well explained! many thanks

[@m.b.smoshitoa8325]

WONDERFUL MY MAN. I DID NOT UNDERSTAND THIS BEFORE BUT NOW I HAVE THE GUTS TIO GO OPEN GEARBOX. LOL MOSHITOA ( S AFRICA)

[@TheAnonymous1one]

Question: Since the small clutching teeth is what mechanically locks the free spinning speed gear to the shaft and actually transfers the power why dont we see more of those stripped vs the actually gear teeth on high powered cars? It looks like it has much less material engagement would seem to be the weak link. I would also think the narrow sleeve that couples the two together would be prone to strip out before the actual speed gear teeth would strip under high power.

[@DrivelineMaster]

1) the small clutching teeth are already 95% in alignment with the teeth on the gear before the sleeve is allowed to slide onto the gear so there is no grinding. This is accomplished by the proper operation of the blocker ring. When the blocker ring becomes worn out and can no longer perform properly that is when the clutching teeth start the grind during the shift. This is the grinding noise that can be heard by the driver between shifts and is called gear clash. The reason these tiny teeth can handle the torque comes from the total surface area contact between the gear and the sleeve. The number of teeth and the length of the teeth determine the total contact surface area. I'm not an engineer but this is something that has to be engineered into the design. They must determine the maximum torque that the synchronizer and gear would have to be able to handle and how much contact is needed.

[@brianb-p6586]

Between two gears, only one tooth on each gear is engaged with the other gear at any time. Between the parts of the synchronizer assembly, all of those small teeth are engaged at the same time, spreading the load out between them. Many small teeth are as strong as one large tooth.

[@johng69er]

Great clear video thank you

[@ryanhewett1663]

very informative; thank you.

[@user-bu5ye3mr5w]

Kids used to say they could drag race powershift as in brute force abuse without using the clutch, but the way the synchronizer is designed, this is impossible, because the harder you try to force a shift, the harder the synchro will ride up onto the cone and fight to prevent it

[@armedfarm3429]

After several videos trying to figure this out, I finally get it. Excellent video. Now I wonder if there would be other ways to slow shaft/gear speed. Synchro's are spendy parts "labor wise" to replace. I also wonder what fluid would cause the least amount of wear & still give satisfactory shifting.

[@DrivelineMaster]

Unless a specialized fluid is specified and the spec is 75w-90 or 80w-90 GL4 I really like Redline Manual Transmission Fluid (MTF)

[@josephschaefer9163]

Good ole stinky 80-90 gear lube is the highest temp rated fluid

[@armedfarm3429]

Up here in MN maybe a 75-85 would be a good choice. I think up in the cold states an ATF is hard to beat. @@DrivelineMaster

[@DrivelineMaster]

I don't want to give the wrong information. Most manual transmissions can not and should not use ATF. ATF can only safely be used in a manual transmission if and only if the service information or owners manual says so. Never use ATF in a manual transmission unless it has been specified by the manufacture as an acceptable winter oil option.

[@luca490]

Beautiful video sir.

[@5speedMax]

That is a very cool visual.

[@isabelgarcia891]

Thank you great explanation

[@Joeelectronicschematicsforauto]

This was absolutely awesome these videos should be in schools to teach students

[@DrivelineMaster]

They are used in all my classes.

[@MrApplefreaker]

Is my understanding right in saying that the blocker ring is made of a different material (bronze maybe?), so as to provide a higher coefficient of thermal expansion and thus allow faster expansion when a lot of heat is generated due to excessive friction generated when synchronization is not possible and thereby block the meshing of the speed gear teeth and synchronizer hub teeth? Is this how the blocking ring acts to block the meshing when speeds aren't synchronized?

[@DrivelineMaster]

Well said. That is correct. Blocker rings are made out of other material but it's always soft and sometimes lined with friction material similar to a brake lining however it is the thermal expansion from the inability to synchronize that pushes back on the keys and sleeve to prevent the sleeve from moving over and grinding the gear teeth.

[@MrApplefreaker]

@@DrivelineMaster Thank you, that cleared it up.

[@TECsta76]

Would a block on 1st and 3rd which causes popping out (both gears on the same side of the shifter) mean anything specfic?

[@tb-skyline-auto9836]

I don't think I have ever seen a synchronizer with 1st on one side and 3rd on the other. Normally 1st and 2nd and 3rd and 4th or I have seen 1st and Reverse and 2nd and 3rd and 4th and 5th. So a worn blocker typically will not cause jumping or popping out of gear. Normally worn clutching teeth on the gear and on the sleeve cause this. Not those teeth normally get worn down because the blocker is worn and the driver is grinding the gears during each shift. Other things like worn shift forks or loose shifter mechanism. More rare would be week or worn detent springs or misaligned bell housing (older classic cars). He is an odd ball one that I had one time. I had an older VW with a plastic rather stiff shifter boot. The boot was off center and when installed upside down it would exert force on the shifter in the direction of neutral. Under heavy acceleration the boot would exert enough force on the shifter that the vehicle would jump out of gear. Imagine resting your hand on the shifter al the time and while in 1st or 3rd the force of you resting your hand on the shifter was actually putting a slight amount of pressure on the shifter toward the neutral direction. Under heavy acceleration this will cause the transmission to jump out of gear. It's just one of those odd ball things but it happens, so I mention it to you.

[@TECsta76]

@@tb-skyline-auto9836 Thanks for the reply, when i wrote ''on both sides of the shifter'' i meant 1st gear being Top left and 3rd gear being in Top Middle (both gears are in the same area) but its a normal 5 speed gearbox in a UK Ford Fiesta mach 8... So your saying gears popping out is, in some cases is due to the clutch?

[@DrivelineMaster]

It's extremely unlikely that replacing the clutch will solve a popping out of gear problem. I'm sorry to say that this is typically due to a problem inside the transmission if it's not shifter related such as worn shifter linkage or a improperly installed stiff shifter boot. I recommend that you have a qualified mechanic look at it for you and cross your fingers that its a linkage or shifter problem. One last possibility might be worn out or broken engine and or transmission mounts could do this.

[@shanilkadesilva65]

Great video

[@user-id3tj1gs6y]

Great video! The one part that I don't understand - how does the blocker ring prevent engagement if the gears cannot be synchronized?

[@DrivelineMaster]

Here you go. The sleeve pushes on the keys which push on the blocker ring. The job of the blocker ring through friction between the ring and the gear is to grab the gear and make it go the same speed (synchronize) so the sleeve can slide over and lock the two together. If the blocker ring is unable to synchronize the gear to its speed a lot of friction is taking place. With more friction more heat is generated. With more heat there is expansion of components. The heat and expansion is a counter force pushing back on the blocker ring. That force on the blocker ring is transferred to the keys and then onto the sleeve. The counter force prevents the sleeve from moving close enough to the gear for the clutching teeth to touch. If the clutching teeth are allowed to touch before synchronization a grinding noise (gear clash) will be heard. Hope this helps.

[@Punjabplus0866]

nice vedio thank u

[@romanescalera7752]

Que bueno señor gracias.

[@ArunaVidu]

I have 2 questions. 1) At the end 7:43 does the speed gear clutching teethes rotate? I see the angle cut teeth rotation, but not the clutching teethes. 2) And even with the clutch engaged, the counter shaft still rotates at a very high speed.lets say vehicle is stationary and starting to move. so there is no axle shaft or output shaft rotation. but the speed gears will have high speed rotation. So how does the synchronizer ring slow down the speed gear to make the connection in less than a second.

[@mugen-mundo]

The speed gear appears stationary thanks to the use of the strobe light. The counter shaft is in mesh with input not output.

[@LibertyWarrior68]

I'm getting ready to rebuild my gearbox, so I'm learning as much as I can.

[@kidicarus2637]

thanks, very helpful!

[@avleerxo]

Great great. It will helpme to modify my 1975 vw bug trans to 5 speed.

[@e-curb]

The first step is to buy the 5 speed conversion kit. It's $2k. Then you have to buy two gear sets ($500). The same co that makes the conversion kits also make a shifter that works with the 5 speed ($300). Find a mid 60s core trans to supply you with a few stock parts you will need.

[@wubbaddubbalublubme4830]

So I get that the speeds match up thanks to the blocker ring, but how do the teeth on the gear, blocker ring, and sleeve match up with each other?

[@GroovesAndLands]

The internal teeth of the sleeve match up just right to the clutching teeth (dogs) on the speed gear as well as the blocker ring. Thus, the sleeve is free to slip over them - but once it does, they must spin together. So when the sleeve is pushed towards the speed gear, the sleeve pushes on the shift keys, which push on the blocker - all towards the speed gear. The internal cone of the blocker presses against the external cone on the speed gear, developing friction and either speeding up or slowing down the speed gear until it matches the speed of the hub/sleeve/blocker assembly. Once that happens, the sleeve can be pushed over the blocker and onto the the clutching teeth of the speed gear - thus coupling the speed gear to the sleeve, and therefore the hub, and therefore the output shaft.

[@DrivelineMaster]

The blocker ring rotates with the hub but the blocker ring is not fixed to a position but instead because the connection takes place because of the keys and the cut out on the ring. The ring can rotate separately about 2-4 degrees from the hub. The teeth on the sleeve, blocker ring and gear are space about 1-3 degrees apart. Because the teeth are cut at a pointed angle they don't have to align up perfectly. The video shows that sometimes but even being off slightly when the sleeve starts to move towards the gear the points on the teeth if not perfectly aligned will slide from one side of the tooth or the other forcing alignment. Kind of difficult to explain. I hope this made sense. Imagine two really sharp pencils and trying to hold them point to point. Unless you get it exactly perfect on each point as you move the points towards each other. If you miss hitting the point perfectly they will slide off the point to one side or the other. It's like that.

[@JP-uk9uc]

So, what exactly is broken when you shift, it feels like it goes into gear, but no it pops out or you can feel some grinding? I assume the key is broken or the synch ring just spins and make shifting fail routinely?

[@DrivelineMaster]

Based on your description it's really hard to tell exactly what you are experiencing. Here is what can happen. As the vehicle gets older and gets some mileage on it the transmission the fluid additives start to wear out. If the fluid is not replaced wear on the synchronizer blocker ring starts. If the transmission is abused or worked harder than normal the wear accelerates. Once the lube doesn't work as well because the additives are worn out or the transmission is driven with a bad clutch the synchronizer blocker rings are no longer capable of synchronizing properly and the drive starts forcing the shift, just a little and just a little grinding starts to happen. This grinding takes place between the small clutching teeth on the blocker ring, gear and synchronizer sleeve. As the wear continues shifting becomes harder and the driver forces the shift some more placing additional load and wear on the shift forks and the sleeve fork groove. The forcing of the shift also places an extra load on the keys. Some keys are stamped sheet metal and these bend and become damages easier than solid steel keys. Jumping out of gear starts to happen when the clutching teeth are heavily worn and or the shift forks are also heavily worn. It's rarely a broken key or worn key that will cause the jumping out of gear. If this is an older vehicle with external shift linkage worn or maladjusted shift linkage along with worn or broken engine and transmission mounts can also cause jumping out of gear. Additionally on older vehicles 1960 to mid 1970 vehicles could have misaligned bell housing. If the center of the bell housing is not in alignment with the center of the crankshaft it can cause a twisting bind the can cause jumping out of gear but this is rare. You most likely have severely worn synchronizes, clutching teeth on the gear and sleeve as well as the blocker ring and possibly shift fork wear.

[@tomassvec162]

Hi, thanks for a great video :) Does it also mean, that If you you have your speed shifted already and you want to unshift it into neutral, you don´t have to press the clutch pedal? Just for shifting from speed into neutral. The ring and the speed are synchronised and if you separate them, only after that the speeds will slowly start to differentiate. Do I understand that right? Is it necessary to use clutch when shifting to neutral? Or is it not good to do that and can it cause some damage ?

[@DrivelineMaster]

You do not need to use the clutch when shifting from any gear into neutral. There is a small amount of stress taken off of the components if you do use the clutch but not enough to cause any damage doing this. My sister was so superb at speed matching all the gears by just using the gas pedal that she could up-shift without the use of the clutch and as a passenger you would have never known. This too does not hurt the transmission or the clutch but keep in mind it is far and few people who can pull this off, not even me.

[@soaringvulture]

@@DrivelineMaster Then there was the time my clutch cable broke when I was driving on I-5 in Orange County. I had to learn how to shift without the clutch real quick. It can be done but I'm sure I didn't do the transmission any good.

[@DrivelineMaster]

You do not need to use your clutch to shift from gear to neutral and no harm will be caused. In fact if you are good with speed matching you can upshift and downshift without the clutch and without grinding the gears. I have seen it done by some very talented drivers. If you can do this without grinding the gears there is no harm in it and in fact your clutch will last longer. I too had a clutch cable break while driving in downtown San Francisco in semi rush hour. This was a very interesting drive into work but I did it without using the clutch.

[@DrivelineMaster]

See my reply

[@preston1614]

@@DrivelineMaster I'm a stick shift driving instructor, in the advanced course I try to teach people how to clutches shift (floating the gears), I think, if done properly, it's the best and most comfortable way to shift a manual. However, someone is arguing with me on facebook saying that this will wear down the syncros. I'm sure they are wrong and I think you have already answered this question in your replies but have you any specific input?

[@larryanderson8049]

Not many explanations go into the importance of the key springs and tapers that let the pressure build against the friction ring and bring the gears to the same speed. Then suddenly snap and engage the teeth.... to me that is the most important function of the syncro.