hard shifting when flooring it

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Old 20 Mar 2006, 10:15 am   #1 (permalink)
mrdarrett@gmail.com
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Default hard shifting when flooring it

My '96 camry shifts very smoothly when I drive it "normally" (sanely).
Almost can't even tell that it shifts.

When I get the urge to floor it, though, I notice that it shifts fairly
harshly at around 5000 rpm. (The car doesn't shift so harshly it does
a back-flip, but the shifting is very noticeable.)

Is this normal?

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Old 20 Mar 2006, 10:28 am   #2 (permalink)
m Ransley
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Default Re: hard shifting when flooring it

You can drive a car easy and have no issues for 300,000 miles with luck,
you can put a car on a race track and blow it in 10 minutes. Slamming
into gear just doesnt sound righ does it. Try a oil and trans filter
change.

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Old 21 Mar 2006, 08:53 am   #3 (permalink)
Daniel
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Default Re: hard shifting when flooring it

Actaully, full throttle upshifts should take place closer to 6,000 rpm.
They will be harsher than part throttle upshifts, but it the valve body
is operating correcting they should not be particularly jarring.
As Mark says, transmission fluid should be clean.
Also you could adjust the throttle cable for full open at wide open
throttle.
When I disassembled and cleaned the throttle body, the manual gave
several adjustments. One of these is the throttle position sensor. On
my '94 it did require some adjustment.

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Old 21 Mar 2006, 12:55 pm   #4 (permalink)
Jason James
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Default Re: hard shifting when flooring it


<mrdarrett@gmail.com> wrote in message
news:1142871308.696229.312190@g10g2000cwb.googlegr oups.com...
> My '96 camry shifts very smoothly when I drive it "normally" (sanely).
> Almost can't even tell that it shifts.
>
> When I get the urge to floor it, though, I notice that it shifts fairly
> harshly at around 5000 rpm. (The car doesn't shift so harshly it does
> a back-flip, but the shifting is very noticeable.)
>
> Is this normal?


Yes it is for many higher mileage automatics. Automatic transmissions work
by changing gear-ratios using hydraulically operated bands which grab onto
drums and clutchs which operate and release. If you an imagine or remember
the rear brake on older (as in 40 years ago) kid's scooters where a
semicircle of spring steel lined with a friction material is applied around
the drum on the rear wheel, hence causing the drum/wheel slow to a
stop,..then you have a similar principle in automatics when they change
gear.

Now while the trans is new the gap between the band and the drum is small.
This means there is a smoother action with little noise,..however, once the
band's friction lining and to some extent the drum's surface wears (which
gives rise to swarf in the trans pan) the time taken for the band to tighten
around the drum increases *and* the band's speed increases due the extra gap
before it contacts its drum. This causes the thump or jerk as the auto
changes gear.

During trans servicing, these increased gaps are to some extent decreased by
adjusmnts so the thump is reduced, however, other parts of the auto are also
wearing including the internal oil-pump which provides the motivating force
(oil-pressure) to apply the brake-band. So just because the band clearance
to the drum has been returned to normal, the OP cant provide sufficient
pressure in time. This causes slipping and that characteristic "wheeeup"
noise in some autos.

The best thing is not to thrash the transmission which has high miles on it,
as it just acceleraes more wear. The clutch=paks in autos suffer a similar
fate as the brake-bands. Its important to ask the auto-servicing place if
there was much metal in the oil-pan. The more there was, the greater need to
go easy on the trans.

Jason


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Old 21 Mar 2006, 01:17 pm   #5 (permalink)
mrdarrett@gmail.com
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Default Re: hard shifting when flooring it


Jason James wrote:
> <mrdarrett@gmail.com> wrote in message
> news:1142871308.696229.312190@g10g2000cwb.googlegr oups.com...
> > My '96 camry shifts very smoothly when I drive it "normally" (sanely).
> > Almost can't even tell that it shifts.
> >
> > When I get the urge to floor it, though, I notice that it shifts fairly
> > harshly at around 5000 rpm. (The car doesn't shift so harshly it does
> > a back-flip, but the shifting is very noticeable.)
> >
> > Is this normal?

>
> Yes it is for many higher mileage automatics. Automatic transmissions work
> by changing gear-ratios using hydraulically operated bands which grab onto
> drums and clutchs which operate and release. If you an imagine or remember
> the rear brake on older (as in 40 years ago) kid's scooters where a
> semicircle of spring steel lined with a friction material is applied around
> the drum on the rear wheel, hence causing the drum/wheel slow to a
> stop,..then you have a similar principle in automatics when they change
> gear.
>
> Now while the trans is new the gap between the band and the drum is small.
> This means there is a smoother action with little noise,..however, once the
> band's friction lining and to some extent the drum's surface wears (which
> gives rise to swarf in the trans pan) the time taken for the band to tighten
> around the drum increases *and* the band's speed increases due the extra gap
> before it contacts its drum. This causes the thump or jerk as the auto
> changes gear.
>
> During trans servicing, these increased gaps are to some extent decreased by
> adjusmnts so the thump is reduced, however, other parts of the auto are also
> wearing including the internal oil-pump which provides the motivating force
> (oil-pressure) to apply the brake-band. So just because the band clearance
> to the drum has been returned to normal, the OP cant provide sufficient
> pressure in time. This causes slipping and that characteristic "wheeeup"
> noise in some autos.
>
> The best thing is not to thrash the transmission which has high miles on it,
> as it just acceleraes more wear. The clutch=paks in autos suffer a similar
> fate as the brake-bands. Its important to ask the auto-servicing place if
> there was much metal in the oil-pan. The more there was, the greater need to
> go easy on the trans.
>
> Jason



Ok, thanks for the detailed explanation.

I changed the tranny gasket and strainer about a month or two ago,
didn't find a whole lot of metal, just some metal dust on the
magnets...

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Old 22 Mar 2006, 11:29 am   #6 (permalink)
oparr
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Default Re: hard shifting when flooring it

>When I get the urge to floor it, though, I notice that it shifts fairly
>harshly at around 5000 rpm.


Check kickdown cable adjustment.

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Old 22 Mar 2006, 11:46 am   #7 (permalink)
mrdarrett@gmail.com
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Default Re: hard shifting when flooring it


oparr wrote:
> >When I get the urge to floor it, though, I notice that it shifts fairly
> >harshly at around 5000 rpm.

>
> Check kickdown cable adjustment.


Is this one in the Haynes manual? (I don't have a Haynes in front of
me, and won't, until later this evening.)

Thanks,

Mike

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Old 22 Mar 2006, 02:14 pm   #8 (permalink)
oparr
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Default Re: hard shifting when flooring it

>Is this one in the Haynes manual?

Should be, it may be called "throttle cable" since it goes from the
throttle to the transmission. IIRC, there is usually some confusion
regarding "accelerator cable", "throttle cable" and "kickdown cable".
The latter two are the same in many cases.

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Old 22 Mar 2006, 02:18 pm   #9 (permalink)
mrdarrett@gmail.com
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Default Re: hard shifting when flooring it


oparr wrote:
> >Is this one in the Haynes manual?

>
> Should be, it may be called "throttle cable" since it goes from the
> throttle to the transmission. IIRC, there is usually some confusion
> regarding "accelerator cable", "throttle cable" and "kickdown cable".
> The latter two are the same in many cases.



Thanks!

I'll also try and curb my urge to floor it. ;0

Mike

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Old 23 Mar 2006, 07:19 am   #10 (permalink)
skewe
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Default Re: hard shifting when flooring it

Could be that ur engine mounts are slowing giving way

http://www.golfer-review.com/m_toyota/camry.htm

mrdarrett@gmail.com wrote:
> oparr wrote:
> > >Is this one in the Haynes manual?

> >
> > Should be, it may be called "throttle cable" since it goes from the
> > throttle to the transmission. IIRC, there is usually some confusion
> > regarding "accelerator cable", "throttle cable" and "kickdown cable".
> > The latter two are the same in many cases.

>
>
> Thanks!
>
> I'll also try and curb my urge to floor it. ;0
>
> Mike


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