Does gear shifting wear a transmission?

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WhoBeDaPlaya

Diamond Member
Sep 15, 2000
7,415
404
126
My LS has a tendency to gear hunt around 45-50 if left in D5. So I just drive in D4 for in-city driving.
 

Doppel

Lifer
Feb 5, 2011
13,306
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Did someone just post a thread asking about automatic transmission wear...and then, in the space of the very same thread, suddenly become an expert on the subject?

:hmm:
lmao, this is pure internet awesomeness right here
 

Jeff7181

Lifer
Aug 21, 2002
18,368
11
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You assumed that is what I said, it is not. Not even close...

In an automatic transmission the clutches control what parts of a planetary gear set move, and what parts do not. They are only responsible for stopping the inertia of small pieces of metal and holding them in place.

In a manual transmission the clutch connects the engine's output to the transmission and slips until the engine and wheels match speed.

Clutches in an automatic and manual transmission function in a fundamentally different way.

That's incorrect. You have a driven member and a driving member, just like with a manual transmission. The load is still there, and it's exactly why aftermarket clutch packs for automatic transmissions sometimes include extra frictions and steels - to put up with the abuse of a higher output engine or a heavier vehicle. Not because the planetary gear set is heavier in one transmission vs. the next.
 

kalrith

Diamond Member
Aug 22, 2005
6,628
7
81
My 2001 Mazda Tribute was horrible with gear-hunting. I'd have the cruise set anywhere from 65-80 on the highway and it would downshift to 3rd for the very slightest incline or even if there was a gust of wind on a flat road. Driving from SW Missouri to Tulsa would probably result in 50+ downshifts with the cruise set to 5 over the speed limit the whole way. When I drove my other car ('92 Mercury Cougar) to Tulsa, it would only downshift 2 to 3 times with the cruise set to the same speed as the Tribute.

What's really sad is that my new 125hp Suzuki Forenza seems to have more gumption in 4th gear than my 200hp Tribute. It doesn't downshift to third much more than my Cougar does.

The Tribute tried to be resourceful and fixed the gear-hunting problem on its own. It broke the intermediate band, so now it only has 1st and 3rd gears, so there's no gear hunting on the highway anymore :)
 

hanoverphist

Diamond Member
Dec 7, 2006
9,867
23
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i love these threads, they amuse me.

i have a dodge truck with a 5sp manual trans in it, 4 months after i got it i had my clutch pretty much explode. it had 84k miles on it. ive since gotten the mileage up to 225k (in 4 years) and am still on the same clutch. my old datsun wasnt as lucky, it lasted about 120k before i trashed the clutch. i tend to drive it like its stolen, but i have fun.

my older cars that had auto transmissions lasted a long time as well, my 76 impala had the original at 190k just like my 79 stepside 4X4. both transmissions outlasted the engines. there were many other cars, but those two had the most miles. 190k for the impala and 195k for the truck. im surprised the truck lasted that long, about 90k of that mileage was hard, offroad destruction. i sold it with a busted cylinder, 2 frame cracks and a messed up suspension.
 

IcePickFreak

Platinum Member
Jul 12, 2007
2,428
9
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So are you guys saying that using reverse to slow down isn't a good idea? It really saves on having to replace my brake pads.

Which reminds me, I need to go pick up my transmission where I left it.
 

Raduque

Lifer
Aug 22, 2004
13,140
138
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My 4-cyl with no O/D on the 5-speed manual has never bothered me. Gas mileage could be a little better, but it's still got passing power on the highway.

Actually, you DO have an overdrive, only it's not called that; It's called 5th gear.

Overdrive means a higher (numerically lower) top gear ratio than an acceleration gear.

In most manuals, 5th is somewhere around a .8-.6 ratio.

Just one example, from a ZF S5-42 5-spd manual:
Close Ratio
1st Gear: 4.14
2nd Gear: 2.37
3rd Gear: 1.42
4th Gear: 1.00
5th Gear: 0.77
Rev Gear: 3.79
 

simonizor

Golden Member
Feb 8, 2010
1,312
0
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Clutch in a manual only wears when you're releasing it. Once the thing is in gear, there's no slip, no wear, no clutch damage of any kind.

So you're saying that riding the clutch while the vehicle is moving does absolutely no damage?

Why the hell haven't the admins banned this fucking idiot garage troll yet?
 

skyking

Lifer
Nov 21, 2001
22,820
5,984
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So you're saying that riding the clutch while the vehicle is moving does absolutely no damage?

Why the hell haven't the admins banned this fucking idiot garage troll yet?
Because the half-wit is only half-serious.
 

PlasmaBomb

Lifer
Nov 19, 2004
11,636
2
81
Clutch in a manual only wears when you're releasing it. Once the thing is in gear, there's no slip, no wear, no clutch damage of any kind.
So you're saying that riding the clutch while the vehicle is moving does absolutely no damage?

Why the hell haven't the admins banned this fucking idiot garage troll yet?

If you ride the clutch you will cause it to slip... thus making it wear.

Edit: You have enough pressure on the clutch pedal to partially disengage the friction plate on the clutch, allowing it to partially slip.

Unless it means something different in the US...
 
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LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
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Clutch in a manual only wears when you're releasing it. Once the thing is in gear, there's no slip, no wear, no clutch damage of any kind.

So you can take off in high gear with your trailer full of boulders then? If you get it in high gear, there'll be no clutch wear?

If you're in high gear and come to a long, slow, steep, grade, you can just climb the grade in hgh gear then? The clutch won't slip because it was already in gear?
 

skyking

Lifer
Nov 21, 2001
22,820
5,984
146
If you ride the clutch you will cause it to slip... thus making it wear.

Edit: You have enough pressure on the clutch pedal to partially disengage the friction plate on the clutch, allowing it to partially slip.

Unless it means something different in the US...
I believe your sarcasm detector needs new batteries.
 

Howard

Lifer
Oct 14, 1999
47,982
11
81
Well, if your car is in a situation where engine power is not required to make it maintain a constant speed, technically even if you ride the clutch it won't wear since the frictional surfaces are not moving relative to one another.
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
126
Well, if your car is in a situation where engine power is not required to make it maintain a constant speed, technically even if you ride the clutch it won't wear since the frictional surfaces are not moving relative to one another.

If engine power is not required to make the car maintain speed, then you can shut the engine off and save wear on that too, and fuel...
 

Jeff7181

Lifer
Aug 21, 2002
18,368
11
81
Well, if your car is in a situation where engine power is not required to make it maintain a constant speed, technically even if you ride the clutch it won't wear since the frictional surfaces are not moving relative to one another.

Only if the transmission is in neutral. Otherwise the output shaft of the transmission is being driven by the wheels and will be driving the input shaft of the transmission which would be spinning the pressure plate and unless you're VERY good at rev matching WHILE riding the clutch, there's still going to be an RPM difference between the flywheel and pressure plate, and thus slippage and excessive wear.
 

Jeff7181

Lifer
Aug 21, 2002
18,368
11
81
If engine power is not required to make the car maintain speed, then you can shut the engine off and save wear on that too, and fuel...

And you could have hydraulic suspension installed and manipulate it so that you're driving with only three wheels on the ground, reducing rolling resistance and saving wear on one of your tires.