auto transmission problem - 1985 mercury grand marquis 5 l v8

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marks542004@yahoo.com - 07 Nov 2007 18:15 GMT

Hello all,

My Dads car (hes 80) is a 1985 mercury grand marquis with about
180,000 miles we think. The odometer reads 80,000 miles , and my car
which is an 1989 buick has 150,000 miles shown.

Its a v8 engine with automatic transmission. The transmission fluid
seems clean and at the correct level.

While driving about 10 miles to the supermarket the car didnt shift
from first or second gear after he stopped for a traffic light. We
drove slowly into town , and started back and after a few slow miles
it finally shifted but seemed to shift up and down a few times.

It was very erratic for the few miles of the trip left.

We dont feel putting a lot of money into the car is worthwhile , it
was mainly for trailer hauling and he doesnt do that much anymore . A
used 4 cylinder would be more economical on gas .

The question is , is a transmission flush ($100-200) likely to help
the problem or is the transmission likely to need repair . We have a
quote from the local Ford shop of $600 to diagnose the problem with
$1200 - $2500 for repair or replacement . The transmission flush
quote ranged from $80 to $200, the $200 included something to do with
a filter .

I suppose I am asking for an educated guess so any comments are
welcome .

regards

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Steve B. - 07 Nov 2007 23:57 GMT

>Hello all,
>
>My Dads car (hes 80) is a 1985 mercury grand marquis with about
>180,000 miles we think. The odometer reads 80,000 miles , and my car
>which is an 1989 buick has 150,000 miles shown.

Transmission flush probably won't help much or if it does it won't
help for long. You might try some trans-medic to see if it helps with
the issue. It is one of the few snake oils I have had decent luck
with.

Steve B.

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i'm - 08 Nov 2007 02:47 GMT

> Hello all,
>
[quoted text clipped - 27 lines]
>
> regards

A lot of possibilities... The fluid can look clean on the
stick, but a different situation in the pan. Could be the
filter is getting clogged and the seals are brittle and
take a while to soften and do their job. Don't event think
about a flush, it can cause more problems. You might drop
the pan and install a clean filter, then refill with
Dexron-Mercon III and a can of trans -Medic to soften up the
seals. Only thing is, the trans-medic keeps working unless
you remove it. So, after a week or so, I'd drain the pan
again. Do that a couple times and it will probably be good
for a year or so. Hopefully, you can do the stuff yourself.
Otherwise, you're at the mercy of the station-bots...

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tenne - 08 Nov 2007 06:08 GMT

> marks542...@yahoo.com wrote:
> > Hello all,
[quoted text clipped - 43 lines]
>
> - Show quoted text -

If this is a 5.8L(351 W) it has a VV carb with an AOD tranny. One
thing to check is the TV cable. It is a cable that connects to the
throttle mechanism and runs down to the tranny. This cable signals
throttle position to the tranny. If it is sticking it can cause
erratic shifting. As for the flush, I had a 85 Bronco with an AOD. It
had about 190,000 miles on it and started shifting erratically. I did
a flush and it worked wonders. Got me another 30,000 at which time I
sold it.

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