slapmesilly

I just read at the end of the third gear shifting issues thread that Acura indicates skip shifting "can cause premature synchronizer wear." Here is a link to the Acura article. http://www.in.honda.com/Rjanisis/pubs/TS/BTS051201.PDF

I was always under the impression that skip shifting is acceptable, there are no detrimental effects as long as you shift properly (don't ride the clutch, match speed of the engine on the shift).

I currently have an Integra GSR and have been skip shifting since it was new 10 years ago. I don't think I am "lazy" as the Acura article says, in my mind I have just tried to balance wear on the engine and wear on the clutch. It takes me almost an hour to go 15 miles so I do a lot of shifting from light to light. Going from 1st to 3rd saves one shift, therefore reducing clutch wear, and lets me get to the next light at moderate engine rpm's. To me it was a good balance but maybe I am wrong.

I have to say that I lean towards easy driving, not hard. My Integra has 120,000 miles on it and I still have the original clutch. It is not as tight as when I bought it but it is still original.

Do I need to rethink what I am doing when I pick up my ordered 6MT TL next month?

SKIUL8R

I don't know the answer to this question but it seems like an irresponsible thing to say in that memo, since skip shifting is EXACTLY what automatics do.

I always respected skip shifters since they know what there car is doing. They know exactly where they want to be in terms of both speed and RPM's. If I'm entering a highway and I need some fast excelleration to merge and just happen to be up to 70 in 3rd gear, why in the world would I want to go to forth or maybe even 5th when I want to stay at that speed? I'll just drop it into 6th and not worry about it.

If our cars really do MAP our driving styles for maximum performance, then let it MAP the skip shifts too

Actuary

that sounds gay. what if you are on highway merging lamp and you need to go to 2nd from 4th?


Even my automatic needs to go from 4th->2nd sometimes to merge at low speeds(say 40MPH - 3rd gear doesn't give me enough acceleration)

HiTEC

I've always skip shifted in all my manual cars.

I typically start in 1st, then go to 2nd, 4th, then 6th. When I not in a hurry, that how I typically drive it.

miiipilot

Hi, my name is miiipilot and i'm a skip shifter

Here's my scenario. I drive pretty aggressively.
1st gear: 4000-5500 shift
2nd gear: 4000-5500 shift
3rd gear: 4000-5500 shift
4th gear: 4000-5500 shift
Now im a 75-90 crusing speed right
Why would I go to 5th?
Straight to 6th.

Downshifting: Freeway driving
6th to 4th with "blipping the throttle" <--heel toe w/o the braking
4th gear to pass or whatever shift to 6th.

Hmmmm now I'm wondering what I use 5th for.

I hope I'm not damaging anything. I've been driving like that for a while. Even with my E36 M3, I went from 3rd to 5th (No 6th)


miiipilot

blaze6257

it only really means if you like are accelerating and you do that and have the car at too low of an rpm and try to go fast. just make sure you have the car at the proper rpm and in the right gear to accelerate

Brettg

It should be safe to do anything in 5th and 6th, as those gears do not have syncros. Its not unusual to be in a situation where you use 3rd gear or 4th gear to get up to say 70 mph fast, then go right into 6th.

If you rev match, the syncros in the lower gears are not going to be doing anything anyway, so that is also no problem.
I dont think its good for the syncros is you dont rev match, but just how much wear they would get, and how long they would last is a good question.

Its a manual transmission, and you should be able to do whatever you want to it within reason, without it wearing out or blowing up, thats what a manual is all about. To say you can not go from 6th directly to 4th to get the performance,
or the other way around is just nuts, somebody wants to race or just pass quickly and you are going to go from 6th, to 5th, to 4th??? That seems stupid!

Brett

slapmesilly

Well, I think everyone has confirmed my thinking. Shifting properly does not hurt components or cause unnecessary wear.

It is a mazing to me that a manufacturer would put out information that is basically incorrect. (I am assuming the Acura Tech Line article is in fact published by Acura). If they explained the proper shifting technique and THEN noted how shifting incorrectly can wear the synchros it would have been a good article.

And what is the hiring process like at Acura if they are getting technicians that don't know how to shift?

Bottom line, like miiipilot, I am a Skip Shifter.

jdb8805

I've always felt that if you are going to skip gears (either downshift or upshift), then you should do 2 things:

1) rev match to ease the pressure on the clutch and drivetrain
2) depress clutch - take out of gear - release clutch - rev-match - engage clutch again - put into another gear.

This should also help the syncros.

Austin219

I've been driving mt's forever and I always skip shift. I personally wouldn't worry about it.

sr47567

Hey Folks,
An issue is that (I too am a skip shifter) with the new 2010 TL 6Sp, Tech Line seems to think that skip shifting causes a failure in the Hill Start Assist. I had the Hill Start Assist failure light up at 67 miles on my brand new 2010 TL 6Sp (i picked it up with 9 miles on it). So does it really make sense that skip shifting would now cause an error (an unrelated one at that) after only 59 miles of driving?

SouthernBoy

Yes, they certainly do have synchronizers. The first four forward gears have multi-cone synchronizers. Fifth and sixth do not - but they absolutely do have synchronizers.

SouthernBoy

Acura didn't put out any bogus information about this. What they did is to cover themselves because skip- hifting, when not done properly WILL shorten the life of your synchronizers. Most people when skip shifting (when upshifting) do not wait long enough for engine speed to decrease before they attempt their shift. This means that the synchronizers have to work harder to match shaft speeds for the higher gear. This is where the problems lie.

Your best bet is not to skip shift at all. But if you feel you must, learn how to time your shifts correctly and don't force the upshift. This also has another down side. You will be left with no power to the drive wheels for a longer period of time.

Think about what you're doing when you do this.

acuratech239

iTrader: (2)

Wow lots of incorrect info, but at least a little correct info.

At least someone caught the comment about there "not being syncros on 5th and 6th"

Second, 5ATs don't skip gears. They may feel like they do, but they don't. This is a fact, as the all new 6AT found on the ZDX and 2010 MDX is the only one that can actually skip down two gears at a time, in any combo. This is stated clearly on all of training, as it is supposed to be a selling point for the salespeople. And after driving them a few times, it is clearly evident.

Further more, southerboy said it pretty well and was accurate with his reasonings, so props to you

Personally, I don't skip shift (I have enough problems with my trans), aside from every once and awhile, if a quick downshift is needed (passing, etc).

To each their own though!

SouthernBoy

There certainly have been times when I have skip-shifted for both upshifts and downshifts. When I have found it necessary, or just fun, to hit it in the lower gears to get up to speed, I have skip-shifted from 4th to 6th. Conversely, there have also been times when I have found it necessary to go from 4th to 2nd on a downshift. But I know what I'm doing and I know how things work in my clutch assembly and my transmission. That means I fully understand the need for matching shaft speeds and double clutching and gear ratio variances and other techniques to eliminate both wear and danger to my components.

Under normal driving conditions, I never skip-shift because it buys nothing.

Integral212

@SB & Acuratech - I wonder if this is a similar issue to what the S2K folks see.

See (long thread, but good info):
http://www.s2ki.com/forums/index.php...=237209&st=100

Basically, for the S2K, by skip shifting the synchro doesn't have time to properly match speed after the cone engages, so people end up mushrooming or grinding off the dog teeth on the sleeve. This then results in either a gear lockout or very difficult shifting. Some people magically "fix" theirs by applying extreme force. But they haven't. What they've really done is cleared away the chewed up portion of the teeth, but the damage is done and they'll intermittently be unable to select the gear.

I guess the dog teeth are supposed to look like this:
^
||

But after skipping, they sometimes end up looking like this:
~~
||

See, for example:
http://imagineauto.files.wordpress.c...3/dsc02118.jpg

Sound like something similar for the TL? I assume for 5/6 the ring goes one direction for 5th, and the opposite for 6th, as in the S2K.

SouthernBoy

The synchronizers will only have time to match shaft speeds if the operator allows time for the input shaft to slow down enough where its speed is near that of the layshaft. If the operator forces the shift as soon as he disengages the clutch, then the synchronizers are taxed beyond their "normal" work load and will experience accelerated wear because they are having to pull the input shaft speed down quickly. When the synchros have worn enough, they will not be able to do their job as they should and therefore, more wear and tear will take place with the dog teeth. Grinding, difficultly in completing a shift, and eventually popping out of gear are most likely going to be the results of such wear.

Sounds to me like you have a very good handle on all of this. Good for you!

nfnsquared