clutch can't engage without making a noise at 80mph

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Old 29 May 2009, 03:56 pm   #1 (permalink)
cpliu
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Default clutch can't engage without making a noise at 80mph

When driving down a hill, I usually leave my gear to neutral and let
the momentum carrying the car. I found if the speed reaches ~80mph, I
won't be able re-enage the 5th gear without make a noise like it would
when you do not step on clutch all the way. If I just step on clutch
all the way and leavethe car slide, I can release the clutch and get
back the gear without any noise.

It appears there is some kind sychronization issue at high speed that
it can't go to the gear smoothly. I don't have gear problem except
sometimes it takes a few try to go back gear.

Does this happen to you too?

My car is 1994 4 cyl. Toyota Camry.



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Old 29 May 2009, 05:20 pm   #2 (permalink)
Sharx35
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Default Re: clutch can't engage without making a noise at 80mph


"cpliu" <spamfreeliu@yahoo.com> wrote in message
news:a4532f39-2175-4224-8eb8-b8dee3f7dda1@r34g2000vbi.googlegroups.com...
> When driving down a hill, I usually leave my gear to neutral and let
> the momentum carrying the car. I found if the speed reaches ~80mph, I
> won't be able re-enage the 5th gear without make a noise like it would
> when you do not step on clutch all the way. If I just step on clutch
> all the way and leavethe car slide, I can release the clutch and get
> back the gear without any noise.
>
> It appears there is some kind sychronization issue at high speed that
> it can't go to the gear smoothly. I don't have gear problem except
> sometimes it takes a few try to go back gear.
>
> Does this happen to you too?
>
> My car is 1994 4 cyl. Toyota Camry.
>
>
>


What kind of nut bar puts their vehicle in neutral going down hills? For
starters, it is illegal in many jurisdictions. It's JUST. PLAIN. DUMB.

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Old 29 May 2009, 05:23 pm   #3 (permalink)
Vic Smith
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Default Re: clutch can't engage without making a noise at 80mph

On Fri, 29 May 2009 22:20:42 GMT, "Sharx35" <sharx35@hotmail.com>
wrote:

>
>"cpliu" <spamfreeliu@yahoo.com> wrote in message
>news:a4532f39-2175-4224-8eb8-b8dee3f7dda1@r34g2000vbi.googlegroups.com...
>> When driving down a hill, I usually leave my gear to neutral and let
>> the momentum carrying the car. I found if the speed reaches ~80mph, I
>> won't be able re-enage the 5th gear without make a noise like it would
>> when you do not step on clutch all the way. If I just step on clutch
>> all the way and leavethe car slide, I can release the clutch and get
>> back the gear without any noise.
>>
>> It appears there is some kind sychronization issue at high speed that
>> it can't go to the gear smoothly. I don't have gear problem except
>> sometimes it takes a few try to go back gear.
>>
>> Does this happen to you too?
>>
>> My car is 1994 4 cyl. Toyota Camry.
>>
>>
>>

>
>What kind of nut bar puts their vehicle in neutral going down hills? For
>starters, it is illegal in many jurisdictions. It's JUST. PLAIN. DUMB.


Camry owner.

--Vic
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Old 29 May 2009, 05:45 pm   #4 (permalink)
Sharx35
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Default Re: clutch can't engage without making a noise at 80mph


"Vic Smith" <thismailautodeleted@comcast.net> wrote in message
news2o025po4mdtvj6tnb0alck374gifqiaeh@4ax.com...
> On Fri, 29 May 2009 22:20:42 GMT, "Sharx35" <sharx35@hotmail.com>
> wrote:
>
>>
>>"cpliu" <spamfreeliu@yahoo.com> wrote in message
>>news:a4532f39-2175-4224-8eb8-b8dee3f7dda1@r34g2000vbi.googlegroups.com...
>>> When driving down a hill, I usually leave my gear to neutral and let
>>> the momentum carrying the car. I found if the speed reaches ~80mph, I
>>> won't be able re-enage the 5th gear without make a noise like it would
>>> when you do not step on clutch all the way. If I just step on clutch
>>> all the way and leavethe car slide, I can release the clutch and get
>>> back the gear without any noise.
>>>
>>> It appears there is some kind sychronization issue at high speed that
>>> it can't go to the gear smoothly. I don't have gear problem except
>>> sometimes it takes a few try to go back gear.
>>>
>>> Does this happen to you too?
>>>
>>> My car is 1994 4 cyl. Toyota Camry.
>>>
>>>
>>>

>>
>>What kind of nut bar puts their vehicle in neutral going down hills? For
>>starters, it is illegal in many jurisdictions. It's JUST. PLAIN. DUMB.

>
> Camry owner.
>
> --Vic


This is a Toyota newsgroup--haul your ricer ass back to the Honda groups.



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Old 30 May 2009, 12:51 am   #5 (permalink)
MasterBlaster
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Default Re: clutch can't engage without making a noise at 80mph


"cpliu" wrote

> When driving down a hill, I usually leave my gear to neutral and let
> the momentum carrying the car. I found if the speed reaches ~80mph, I
> won't be able re-enage the 5th gear without make a noise like it would
> when you do not step on clutch all the way. If I just step on clutch
> all the way and leavethe car slide, I can release the clutch and get
> back the gear without any noise.


Simply (and not very technically) put, the transmission has 2 "sets" of gears.
One set spins at the same speed as the engine (via the clutch), the other set
spins with the differential, which is connected to the wheels. When you're flying
down the hill, the gears connected to the wheels are spinning away in there, fast
enough to make a milkshake, while the gears connected to the clutch are
(relatively speaking) standing still.

Trying to ram the gears together when they're spinning at such different speeds
will cause "gear clash", as the spring-loaded synchronizers that help the gears
to mesh smoothly just can't keep up.

If you insist on driving like this, you'll have to learn to partially "double-clutch".
This is when the car is already moving, and the transmission is in neutral (or the
synchros are worn out). You rev the engine to match the speed that it "should" be
at in a particular gear, then (since both sets of gears are now turning at more-or-less
the proper speed), you quickly push the clutch pedal down and shift into the correct
gear before the engine-side gears have a chance to slow down. This usually must be
done within 1/4 second or so, or you'll grind the gears.

-- Side-note:
With a LOT of practice, it's possible to drive without using the clutch at all (except for
starting off from a light). It happened to me years ago when my VW clutch cable broke.
At the light, engine off, in 1st gear, light changes, turn the key, chugchugchugchug and
I'm driving down the road in 1st gear. Get the revs up to where I would normally shift,
let off the gas just a bit so I can pop the shifter into neutral, wait for the engine to slow
to the "normal" speed for shifting, and gently slide the lever into 2nd. Rev, pop, wait,
slide into 3rd. Same for 4th. To shift down, let the car slow, neutral, rev, gently into 3rd.
A bit harder to shift down, but possible. Drove for about 3 miles that way (in city traffic)
to the dealer where I bought a new cable, then to a garage for a big glob of grease,
then another 5 miles home, where I changed the cable.


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Old 31 May 2009, 07:56 am   #6 (permalink)
ACAR
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Default Re: clutch can't engage without making a noise at 80mph

On May 29, 4:56*pm, cpliu <spamfree...@yahoo.com> wrote:
> When driving down a hill, I usually leave my gear to neutral and let
> the momentum carrying the car. I found if the speed reaches ~80mph, I
> won't be able re-enage the 5th gear without make a noise like it would
> when you do not step on clutch all the way. If I just step on clutch
> all the way and leavethe car slide, I can release the clutch and get
> back the gear without any noise.
>
> It appears there is some kind sychronization issue at high speed that
> it can't go to the gear smoothly. I don't have gear problem except
> sometimes it takes a few try to go back gear.
>
> Does this happen to you too?


You've worn out your sychronizers due to your coasting and gear re-
engagement without "double clutching." Coasting like this is illegal.
And risky. And, now, costly. Hope you think you've coasted enough to
pay for the transmission work. But we all know you haven't.
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Old 01 Jun 2009, 12:20 pm   #7 (permalink)
Steve
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Default Re: clutch can't engage without making a noise at 80mph

cpliu wrote:
> When driving down a hill, I usually leave my gear to neutral and let
> the momentum carrying the car. I found if the speed reaches ~80mph, I
> won't be able re-enage the 5th gear without make a noise like it would
> when you do not step on clutch all the way. If I just step on clutch
> all the way and leavethe car slide, I can release the clutch and get
> back the gear without any noise.
>
> It appears there is some kind sychronization issue at high speed that
> it can't go to the gear smoothly. I don't have gear problem except
> sometimes it takes a few try to go back gear.
>
> Does this happen to you too?
>
> My car is 1994 4 cyl. Toyota Camry.
>


Aside from the fact that coasting in neutral is kinda dumb....

You're really over-stressing the 5th gear synchronizer trying to get it
to bring the idling clutch plate back up to high RPM to engage the gear.
4th and 5th gear synchros are less beefy than lower gear synchros and
just are not made to take that kind of abuse.
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Old 01 Jun 2009, 12:29 pm   #8 (permalink)
Steve W.
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Default Re: clutch can't engage without making a noise at 80mph

Steve wrote:
> cpliu wrote:
>> When driving down a hill, I usually leave my gear to neutral and let
>> the momentum carrying the car. I found if the speed reaches ~80mph, I
>> won't be able re-enage the 5th gear without make a noise like it would
>> when you do not step on clutch all the way. If I just step on clutch
>> all the way and leavethe car slide, I can release the clutch and get
>> back the gear without any noise.
>>
>> It appears there is some kind sychronization issue at high speed that
>> it can't go to the gear smoothly. I don't have gear problem except
>> sometimes it takes a few try to go back gear.
>>
>> Does this happen to you too?
>>
>> My car is 1994 4 cyl. Toyota Camry.
>>

>
> Aside from the fact that coasting in neutral is kinda dumb....
>
> You're really over-stressing the 5th gear synchronizer trying to get it
> to bring the idling clutch plate back up to high RPM to engage the gear.
> 4th and 5th gear synchros are less beefy than lower gear synchros and
> just are not made to take that kind of abuse.


Not just dumb but ILLEGAL in every state. It falls under the section of
DMV laws about having control of the vehicle.

The stress on the syncros is NOTHING compared to the stress on that
clutch plate as it tries to deal with the centrifugal force on it. That
plate is NOT designed to handle that without being clamped between the
pressure plate and flywheel.

Wait until that plate explosively fails. It makes a LOT of noise and
tosses part all over!!

--
Steve W.
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Old 01 Jun 2009, 05:43 pm   #9 (permalink)
Nate Nagel
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Default Re: clutch can't engage without making a noise at 80mph

Steve W. wrote:
> Steve wrote:
>> cpliu wrote:
>>> When driving down a hill, I usually leave my gear to neutral and let
>>> the momentum carrying the car. I found if the speed reaches ~80mph, I
>>> won't be able re-enage the 5th gear without make a noise like it would
>>> when you do not step on clutch all the way. If I just step on clutch
>>> all the way and leavethe car slide, I can release the clutch and get
>>> back the gear without any noise.
>>>
>>> It appears there is some kind sychronization issue at high speed that
>>> it can't go to the gear smoothly. I don't have gear problem except
>>> sometimes it takes a few try to go back gear.
>>>
>>> Does this happen to you too?
>>>
>>> My car is 1994 4 cyl. Toyota Camry.
>>>

>> Aside from the fact that coasting in neutral is kinda dumb....
>>
>> You're really over-stressing the 5th gear synchronizer trying to get it
>> to bring the idling clutch plate back up to high RPM to engage the gear.
>> 4th and 5th gear synchros are less beefy than lower gear synchros and
>> just are not made to take that kind of abuse.

>
> Not just dumb but ILLEGAL in every state. It falls under the section of
> DMV laws about having control of the vehicle.
>
> The stress on the syncros is NOTHING compared to the stress on that
> clutch plate as it tries to deal with the centrifugal force on it. That
> plate is NOT designed to handle that without being clamped between the
> pressure plate and flywheel.
>
> Wait until that plate explosively fails. It makes a LOT of noise and
> tosses part all over!!
>


no worse than shifting at 6500 RPM... Now clutches *do* explode but
usually under ultra-high-RPM racing conditions...

That said, to the OP - if you are serious, knock it the heck off. if
nothing else you aren't saving any fuel unless you're driving a real old
car (most modern cars disable the fuel injectors completely if the car
is in gear with the throttle closed and the engine is turning over a
certain RPM threshold) and as others have posted, it's possibly unsafe
and definitely illegal. just leave it in gear and control your speed
with throttle and brake and/or downshifting if necessary

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
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Old 01 Jun 2009, 07:59 pm   #10 (permalink)
Steve W.
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Default Re: clutch can't engage without making a noise at 80mph

Nate Nagel wrote:
> Steve W. wrote:
>> Steve wrote:
>>> cpliu wrote:
>>>> When driving down a hill, I usually leave my gear to neutral and let
>>>> the momentum carrying the car. I found if the speed reaches ~80mph, I
>>>> won't be able re-enage the 5th gear without make a noise like it would
>>>> when you do not step on clutch all the way. If I just step on clutch
>>>> all the way and leavethe car slide, I can release the clutch and get
>>>> back the gear without any noise.
>>>>
>>>> It appears there is some kind sychronization issue at high speed that
>>>> it can't go to the gear smoothly. I don't have gear problem except
>>>> sometimes it takes a few try to go back gear.
>>>>
>>>> Does this happen to you too?
>>>>
>>>> My car is 1994 4 cyl. Toyota Camry.
>>>>
>>> Aside from the fact that coasting in neutral is kinda dumb....
>>>
>>> You're really over-stressing the 5th gear synchronizer trying to get it
>>> to bring the idling clutch plate back up to high RPM to engage the gear.
>>> 4th and 5th gear synchros are less beefy than lower gear synchros and
>>> just are not made to take that kind of abuse.

>>
>> Not just dumb but ILLEGAL in every state. It falls under the section of
>> DMV laws about having control of the vehicle.
>>
>> The stress on the syncros is NOTHING compared to the stress on that
>> clutch plate as it tries to deal with the centrifugal force on it. That
>> plate is NOT designed to handle that without being clamped between the
>> pressure plate and flywheel.
>>
>> Wait until that plate explosively fails. It makes a LOT of noise and
>> tosses part all over!!
>>

>
> no worse than shifting at 6500 RPM... Now clutches *do* explode but
> usually under ultra-high-RPM racing conditions...


You honestly think that a 94 FACTORY Toyota Camry clutch is going to
handle 6500 rpm? Also in shifting you don't just spin the clutch up from
a standing start the way the OP is. AND you certainly don't miss the
shift a few times as was stated.

>
> That said, to the OP - if you are serious, knock it the heck off. if
> nothing else you aren't saving any fuel unless you're driving a real old
> car (most modern cars disable the fuel injectors completely if the car
> is in gear with the throttle closed and the engine is turning over a
> certain RPM threshold) and as others have posted, it's possibly unsafe
> and definitely illegal. just leave it in gear and control your speed
> with throttle and brake and/or downshifting if necessary
>
> nate
>



--
Steve W.
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