Manual Transmission shifting


#1

In a vehicle with a manual transmission, is it okay to shift the gears without the clutch if you are used to doing so without little or no force applied to the shifter? I have made a habbit of doing this with all vehicles because that’s how I learned how to do it in the 10 speed Kenworth used to drive. Example: I work at a Subaru dealership. All of the new Subaru’s are pretty much the same when they have manual transmissions. The gears have their own certain RPM’s that they can slip right into without any force applied to the shifter. Is this not okay to do? I try not to do it much with brand new vehicles because they are NEW!!! and don’t want to mess anything up. Any feedback would be great before I continue doing it.


#2

I’ve done this on occasion, but not as gracefully as you do!
I’m no expert, but I don’t see how it can be a problem. See what the experts say.


#3

Well, if you are good and if you have no lapses you will not do any damage. But few people are really that good and using the clutch is not going to hurt your car or wear out the clutch. If you were to borrow my car, I would ask that you use the clutch. But do what you like with your own car.


#4

Had a friend who drove his manual Jeep Cherokee for a week with no hydraulic clutch fluid…he got pretty good at it…maybe your practicing for just such an occasion ? Being a novice, my question would be…why ?


#5

One thing I dislike about manual transmissions is that I can’t get past 80k without needing a new clutch. i suspect this technique would cut down on clutch wear?

I’ve always wondered, if the clutches in automatic transmissions last well past 100k, why can’t we get a manual clutch as reliable? I do know it’s an apple-oranges comparison, but still… 80k is not much. Lots of people can’t get beyond 50k.

And of course it depends on technique, some others get a lot more than 80k.


#6

but starting is tough. You have to hope the starter/battery is strong enough to get the car moving fast enough to start the engine. Been there, done that.


#7

It’s usually the start in first gear and not the shifting to the other gears that puts the wear on the clutch. I drove a Geo Metro 280,000 miles and the original clutch was still good.

I sometimes wonder why nobody makes a manual transmission that uses a torque converter for first and reverse. It would be a boon to people who launch boats from trailers etc. Dodge had a manual with fluid drive in the late '40s but it used the fluid drive for all gears, resulting in a manual transmission that had an automatic’s inefficiency.


#8

JMHO here, but I’ve done a lot of manual transmission repairs with the vast majority of it being Subarus and I’m not sold on their synchronizers. Most of those Subaru related repairs were related to the synchronizers; or the things that were ground up because of them. The cumulative effect of clutchless shifting over time would worry me a bit.

Sychronizer rings are supposed to be a brake shoe for the gear that it’s attached to and should stop the gear from spinning when the shifter is moved into a certain gear. What I’ve seen many times on Subarus is that brand new synchronizer will not lock onto the gear taper firmly even if the gear is new also. One can have the surfaces completely free of oil, bear down as hard as possible, and the synchronizer ring will still spin on the gear taper. Not good; and this is on brand new unused parts. One can imagine after some thousands of miles of use a gear crunch could become the norm. Personally, I would avoid this habit. Properly driven, a Subaru clutch should easily go 150-200k or more and is much cheaper than repairing the internals of the transmission if it reached that point. Hope that helps anyway.


#9

To float gears as you are without doing any damage, you have to be perfect with your technique 100% of the time. I think your clutch and tranny will last longer if you use the clutch. We professional drivers have a bad habit of thinking we can treat our cars the same way we treat our trucks. Consequently, our cars are usually worn out heaps.


#10

Dodge racer, why not just play it safe and use the clutch? Unless you could show that the wear on the clutch that doesn’t take place would outweigh damage to the other trans components like synchronizers, etc. Does shifting without a clutch in the big trucks save wear on the clutch and other related components? I mean you’re not using the throw-out bearing, right? Things like that. I guess it’s a toss up. As

a truck driver you’re probably pretty good at clutchless shifting. I once had a Suzuki MC whose clutch cable would periodically break at the pivot point, so I’d wrap the cable around my gloved hand and pushing up with my knee against my hand I could dissengage the clutch to take off in 1st gear. I got to where I could shift with no grinding whatsoever into the other gears without disengaging the clutch. I can’t

prove it, but it just seemed to me that I was doing zero damage this way. Hope this helps.


#11

Motorcycle transmissions are designed differently than car transmissions. The synchronizers on car transmissions have fine toothed splines that engage splines on the gears to lock that gear on the shaft. These male and female splined couplings have a close fit and to help align them so they can slide together, the ends of the splined teeth are pointed to cam the male and female into a position that lets them slide together. For this to work, the speeds of the male and female couplings have to be perfectly matched and that’s the job of the synchronizing clutches.

On the other hand, MC transmissions have course toothed, maybe only two or three teeth male and female couplings that have a lot of lash. The ends are square instead of pointed and they just drop together as soon as they are in a position to line up. This design does not have or need synchronizing clutches. A lot of racers upshift without the clutch. They preload the shift lever but the torque of the engine keeps it locked in gear. As soon as he lets off the throttle (or punches a kill switch on drag bikes) the torque interuption lets the couplings separate and the bike goes into the next gear. You should never shift these transmission from gear to gear if the vehicle isn’t moving.
F 1 car transmissions work like this too.


#12

My previous Civic clutch made it to 150k before the plate blew apart into pieces suddenly(not worn much). My wife’s Civic clutch made it 180k miles on original when we sold it. Its really technique, city vs highway driving % followed by clutch design that make it last a certain amount of time.


#13

Regarding motorcycle transmissions, they are not only very different, they are a lot cheaper to replace than a car’s transmission.

Regarding floating gears in a truck, it isn’t done to lessen wear. In fact, if it is done incorrectly, it increases wear. The reason it is done is because it is a lot easier than double clutching, which is required to shift a truck. Truck transmissions don’t have synchronizers, so the driver has to manually synchronize the engine with the transmission. This can be done without using the clutch. Also, a truck clutch is a lot harder to press than a car’s clutch. It takes real effort, especially on an older truck. So with all the extra effort it takes to shift a truck, floating gears allows the driver to pay attention to traffic and less attention to the complicated process of shifting gears.

The hydraulic clutches in most cars are so easy to use and the car transmissions have synchronizers that make shifting with the clutch easy as pie. There is no legitimate reason for floating gears in a car.


#14

And keep avoiding the dealership cars that don’t belong to you either. I’d be ticked if I bought a new car with transmission damage because you didn’t shift at the right time.

I’ve already decided never to let a dealer transfer me a car from another city after seeing way too many cars with dealer plates going 90+ mph down the highway and tailgating…don’t ruin driving around the lot for me too. :slight_smile:


#15

I have had to drive a couple of cars after the clutch cable broke, it was more than just a little bit of fun. I don’t recommend it, it is far less trouble with a clutch. It is also safer for the transmission.


#16

You haven’t had to buy parts for a motorcycle lately, have you?


#17

Sure I have. In fact, you can buy a 6 speed transmission for an Indian motorcycle on Ebay for $625. What kind of car has a new transmission that cheap?