Temperature related transmission whine

I have a '95 Toyota Corolla GLI with a 4 speed automatic transmission.
Lately, it has developed a low pitched whine under load (acceleration,
climbing a hill), which I suspect is from the transmission.
The noise comes on at around 2200-2500 rpm, only at a certain
temperature range.
When the engine is cold, no noise.
After 20-25 minutes drive, noise appears, very audible.
With engine/tranny hot (after some 40-45 minutes drive), noise is gone.
Any help will be greately appreciated.

"Dan" > wrote in message
ups.com...
>I have a '95 Toyota Corolla GLI with a 4 speed automatic transmission.
> Lately, it has developed a low pitched whine under load (acceleration,
> climbing a hill), which I suspect is from the transmission.
> The noise comes on at around 2200-2500 rpm, only at a certain
> temperature range.
> When the engine is cold, no noise.
> After 20-25 minutes drive, noise appears, very audible.
> With engine/tranny hot (after some 40-45 minutes drive), noise is gone.
> Any help will be greately appreciated.
>
Was the transaxle, accessory drive belts, timing belt, etc. serviced
recently?

Check the transmission fluid and see if it looks red and is translucent or
is brown and smells burnt. If it is the latter, have the fluid replaced.

Noises are very difficult to diagnose without actually hearing them. My
recommendation is to have a pro ride with you to hear it.
--
Ray O
correct the return address punctuation to reply

None of the above servicing has been performed recently, but there was
some body repair after accident that caused damage in front. Tranny
fluid is ok. At the shop I've been told noise may come from one of the
accessories (water pump, alternator), but this doesn't make sense since
noise is there only under load.

> wrote in message
oups.com...
>... this doesn't make sense since noise is there only under load.

Actually, it makes very good sense. Alternators often whine under load, but
this is unlikely to be your problem. It could be the power steering pump
(check the level), or the cam belt tensioner bearing. At the very least the
various belts should be checked for wear and damage. Does your engine have a
two piece front pulley? If so it could be separating.

You say the trans fluid is OK. How do you know this?

Stewart DIBBS

Can you explain why a belt tensioner or other accessory bearing may
whine only when accelerating or going uphill and not in idle?
What exactly is a "two piece front pulley"?
It's an automatic tranny, so it's easy to check fluid condition (with
dipstick).

"Dan" > wrote in message
oups.com...
> Can you explain why a belt tensioner or other accessory bearing may
> whine only when accelerating or going uphill and not in idle?
> What exactly is a "two piece front pulley"?
> It's an automatic tranny, so it's easy to check fluid condition (with
> dipstick).
>
When accelerating or going uphill, the engine is producing more torque than
at idle.
--
Ray O
correct the return address punctuation to reply

"Dan" wrote:
>I have a ’95 Toyota Corolla GLI with a 4 speed automatic
>transmission.
>Lately, it has developed a low pitched whine under load
(acceleration,
>climbing a hill), which I suspect is from the transmission.
>The noise comes on at around 2200-2500 rpm, only at a certain
>temperature range.
>When the engine is cold, no noise.
>After 20-25 minutes drive, noise appears, very audible.
>With engine/tranny hot (after some 40-45 minutes drive), noise is
>gone.
>Any help will be greately appreciated.

Hard to be certain but it will be one of two things, the front pump or
the torque converter and in that order would be my guess.

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I'm trying to figure out how (and if) a front collision could have
caused tranny damage like this. Before the accident there was no noise.
The transmission wasn't directly hit in the accident (radiator, bumper
and hood had to be replaced).
Could it be related to a slightly bent chassis or out of spec front
alignment?

"Dan" > wrote in message
oups.com...
> I'm trying to figure out how (and if) a front collision could have
> caused tranny damage like this. Before the accident there was no noise.
> The transmission wasn't directly hit in the accident (radiator, bumper
> and hood had to be replaced).
> Could it be related to a slightly bent chassis or out of spec front
> alignment?
>

When you are looking for advice or information, you should include all the
facts up front so you don't get irrelevant information. Has the car been
fixed yet?

A slightly bent chassis our out-of-alignment condition is unlikely to cause
a transmission whine although either condition can cause premature or uneven
tire wear. A reputable body shop will check chassis and suspension
alignment during repair.

I don't remember the design of your particular car but the if one of the
half-shafts (driveshafts) has a center support bearing that is way out of
alignment, the bearing in it could make noises. A little bit of
mis-alignment on the support bearing shouldn't make noise.

It is possible that front-end damage could cause a power steering fluid
leak, or the power steering fluid could be a little low from seepage over
time. A low fluid level in your power steering reservoir will cause it to
make a moaning/whining sound.

An over-tightened belt can make the bearings in your air conditioner
compressor, power steering pump, and/or alternator wear more quickly, which
would make moaning/whining noises.

Noises are difficult to diagnose without hearing. I recommend that you take
the car for professional diagnosis.
--
Ray O
correct the return address punctuation to reply

Ray O wrote:

> When you are looking for advice or information, you should include all the
> facts up front so you don't get irrelevant information. Has the car been
> fixed yet?

He did in another post. I suggested pinched trans cooler line(s).
That wasn't it. I was out of good ideas at that point.

> I don't remember the design of your particular car but the if one of the
> half-shafts (driveshafts) has a center support bearing that is way out of
> alignment, the bearing in it could make noises.

They don't. The passenger axle is just a regular CV shaft but longer.

> It is possible that front-end damage could cause a power steering fluid
> leak, or the power steering fluid could be a little low from seepage over
> time. A low fluid level in your power steering reservoir will cause it to
> make a moaning/whining sound.

Yup.

> An over-tightened belt can make the bearings in your air conditioner
> compressor, power steering pump, and/or alternator wear more quickly, which
> would make moaning/whining noises.

Yup.

> Noises are difficult to diagnose without hearing. I recommend that you take
> the car for professional diagnosis.

Yup.