Automatic transmissions

I am interested in purchasing a nice 93 Miata with an AUTOMATIC
transmission with 75,000 miles on it. It is for my wife and she does
NOT drive a stick and won't learn. My question is, other than the
obvious power loss, how reliable are these automatics? Do they have
any inherent problems that I should be made aware of?

Jeff

In article .com>,
" > wrote:

> My question is, other than the
> obvious power loss, how reliable are these automatics?

From the lack of repair questions here and on miataforum, I'd guess
their reliability is superb. But automatic Miatas are downright rare, so
prepare to be very flexible about the year and mileage, not to mention
color and optional equipment. If you find an automatic of any sort in
good condition, you should probably jump on it.

--
Lanny Chambers
'94C, St. Louis
http://www.hummingbirds.net/alignment.html

A 93 is getting a bit long in the tooth. On the other hand, There have been
very few complaints about the automatic tranny.
"Lanny Chambers" > wrote in message
...
> In article .com>,
> " > wrote:
>
> > My question is, other than the
> > obvious power loss, how reliable are these automatics?
>
> From the lack of repair questions here and on miataforum, I'd guess
> their reliability is superb. But automatic Miatas are downright rare, so
> prepare to be very flexible about the year and mileage, not to mention
> color and optional equipment. If you find an automatic of any sort in
> good condition, you should probably jump on it.
>
> --
> Lanny Chambers
> '94C, St. Louis
> http://www.hummingbirds.net/alignment.html

Jeff,

Our '90 is an automatic with 110,000 miles on it. We bought it five years
ago when it had 60,000 miles. The AT was introduced mid-year in 1990, so
ours is among the oldest automatic Miatas.

We have minor leaks. Not enough to need continual fluid replacement, but
just enough to spot the driveway. I've found if I'm careful to not overfill,
torque the pan properly and use ATF designed for older transmissions, leaks
can be kept at a minimum. When it gets bad enough I'll yank it out and
replace all the external seals.

The bushing for the shifter pivot has disintegrated, allowing the shifter to
wiggle. I may tear it down and fabricate a replacement as others have done.
Mazda does not sell this 25 cent part separately.

Those are the two problems with our 15-year-old transmission.
--
Ken Lyons '97 Brilliant Black/'90 Classic Red
Inside the Beltway
[Remove the first two digits to reply]

> wrote in message
oups.com...
> I am interested in purchasing a nice 93 Miata with an AUTOMATIC
> transmission with 75,000 miles on it. It is for my wife and she does
> NOT drive a stick and won't learn. My question is, other than the
> obvious power loss, how reliable are these automatics? Do they have
> any inherent problems that I should be made aware of?
>
> Jeff
>

i have a 95bbb with automatic. i didn't set out looking for an automatic
but i am not at all unhappy with it. sure you loose some of the fun of
shifting, but in traffic, which i often find myself in, i don't find a stick
fun at all. and with the automatic you can drive it aggressively if you put
the pedal to the metal. the engine is designed to rev to 7000rpm. with a
automatic you don't get there unless you really stomp on the gas... so you
could get behind the wheel of a automatic and think that it is sluggish, but
that is just by choice, by how aggressively you press the gas or not. i am
not saying that it is the same as a manual but it really is not bad at all.
and yet if someone wants to be drive conservatively it accommodates that
too. i mention this because it actually took me a while to really feel it
was ok to punch it... and it is. and it is fun. as for reliability, all i
can tell you is what i know... i got the car with 100k and thought about
having the transmission flushed but was advised by several people against
doing it. i concluded that it had probably never been serviced and many
people i spoke with believe that it can actually create a problem where
there is none to flush it at this point. i have had it for about 10k and
have not had leaks. seems rock solid. i found that the automatic was a
better value than stick - that is to say that people with the automatics
were selling them below that of comparable manual miatas. i suspect most
people looking to buy a miata simply want a stick and so they are way more
popular. and that is consistent with the fact that automatics represent a
pretty small percentage of all miatas made. i found this price issue to be
the case after looking for a while (months) before i bought. at first i was
not even considering automatics thought i would see them. but then i found
one that looked good and the price was right. i also looked at the 92 and
newer because of my fear of the crankshaft issues that i read about on
miata.net... an expensive repair for those effected.
http://www.miata.net/garage/crankshaft.htmlproblem perhaps it isn't all that
big a deal but i thought why risk it when there was not much difference (if
any) in price for the slightly later years. finally, this page and the
related links are a great read for anyone looking to buy a miata...
http://www.miata.net/faq/usedmx5.html
let us know what you do.
zoom zoom.


> wrote in message
oups.com...
>I am interested in purchasing a nice 93 Miata with an AUTOMATIC
> transmission with 75,000 miles on it. It is for my wife and she does
> NOT drive a stick and won't learn. My question is, other than the
> obvious power loss, how reliable are these automatics? Do they have
> any inherent problems that I should be made aware of?
>
> Jeff
>

Christopher Muto wrote:
> ... i got the car with 100k and thought about
> having the transmission flushed but was advised by several people against
> doing it. i concluded that it had probably never been serviced and many
> people i spoke with believe that it can actually create a problem where
> there is none to flush it at this point.

I've heard this phobia before and have to believe it is bunk. Another
myth perpetrated to keep the American public buying new cars. Inferred
obsolescence. An automatic transmission is a bunch of metal parts
lubricated by oil. The oil viscositry breaks down with time. If it is
not changed, the metal parts do not get the protection they need. Just
like a manual gear box. Furthermore, most repair shops don't even do a
proper flush. It's all a plot.

" > wrote:

>
>Christopher Muto wrote:
>> ... i got the car with 100k and thought about
>> having the transmission flushed but was advised by several people against
>> doing it. i concluded that it had probably never been serviced and many
>> people i spoke with believe that it can actually create a problem where
>> there is none to flush it at this point.
>
>I've heard this phobia before and have to believe it is bunk. Another
>myth perpetrated to keep the American public buying new cars. Inferred
>obsolescence. An automatic transmission is a bunch of metal parts
>lubricated by oil. The oil viscositry breaks down with time. If it is
>not changed, the metal parts do not get the protection they need. Just
>like a manual gear box. Furthermore, most repair shops don't even do a
>proper flush. It's all a plot.

Well, what does it say in the Owner's Manual?

Leon
--
Leon van Dommelen Bozo, the White 96 Sebring Miata .)
http://www.dommelen.net/miata
EXIT THE INTERSTATES (Jamie Jensen)

Interesting physics involved in this too. I hit reverse at 175Kmph, hitting
redline quickly, before dropping below 160. Examining the road revealed a
single black mark (No Limited slip diff). Calcualting gear ratio gives a
speed of 110K in reverse at redline, however as the diff had directed all of
this the the first wheel to break traction, its speed woiuld have been TWICE
110K. This is assuming the other wheel was stationary, whitch it obviously
was not, it was doing 160. Hence add 160 to the speed of that wheel. All
wheel speeds are however relative to the car. The road is traveling at 160
the other way.

Hence, the differance in speed between the bottom of the tyre that broke
traction first and the road it was on was:

540KMph! (a tad over 330 Mph)

No wonder the V8s had trouble matching it.



"Mal Osborne" > wrote in message
...
> IIRC, the Auto Miatas use a Jatco 4N71B transmission. I had a Datsun 240K
> in my teens, I absolutly thrashed the poor thing. I did have a few
> transmission problems, but then the 240K is a larger, more powerful car,
> and my driving style at the time was rather destructive. (hitting reverse
> at 100Mph & flooring it created a cloud of grey smoke that was the envy of
> my friends with large V8s) These transmissions are also bolted up to
> 3Litre VL Commodores here in Australia, a car about the size of a current
> Chev Impala. I would think in a Miata they should be almost bullet proof.
>
>
>
>
> > wrote in message
> oups.com...
>>I am interested in purchasing a nice 93 Miata with an AUTOMATIC
>> transmission with 75,000 miles on it. It is for my wife and she does
>> NOT drive a stick and won't learn. My question is, other than the
>> obvious power loss, how reliable are these automatics? Do they have
>> any inherent problems that I should be made aware of?
>>
>> Jeff
>>
>
>

Leon van Dommelen wrote:
> Well, what does it say in the Owner's Manual?
>

I had to check. It doesn't say. It also doesn't say anything about
changing brake or clutch fluid and I know they degrade with time. I
assume they figure that owners of automatics will ignore such
reccomendations anyway. I know if you get Jiffy-lube to flush your
tranny they will not do a proper job. They only drain it out he bottom
and leave most of the fluid in the case. The there are the owners
would never change the fluid. This lack of maintenace leads to failures
and part of the cycle that keeps the new cars plants and the economy
running.

I mean really, there is no reason you ever really need to replace an
automobile. It's not like the operating system gets upgraded or you
have to run new software. There's no shortage of replacement parts.
They certainly don't slow down or can't run on new roads. A car is like
Rock & Roll. Nobody is inventing anything new, it's just variation on a
theme.

" > wrote in
ups.com:

> I know if you get Jiffy-lube to flush your tranny they will not do
> a proper job.

They'll do exactly the same as any dealer, transmission shop, etc.

> They only drain it out he bottom and leave most of the fluid in
> the case.

They drain *all* the fluid from the case and only leaves whats in
the torque converter (which is a great deal of fluid) and usually
clean or replace the transmission filter, that's all that's needed.

If they drain or flush the torque converter you do NOT want to pay
the bill. There are three ways I know of to drain a torque
converter, one is to remove it and allow it to drain naturally, this
takes a bunch of time, overnight at the very least and still doesn't
get all the fluid out. This is done only if the transmission is
being rebuilt and the torque converter isn't being replaced.

Another way is to drain the torque converter through the drain hole
but no modern transmission I know of has such a drain. Some GM cars
have a boss on the torque converter where a hole can be drilled
using a magnetic drill and tapped using a magnetic tap and then a
plug inserted when the converter is drained. AFAIK only GM had this
setup and I don't believe it's on current GM cars.

The third way is the flush which forces clean fluid through the
system, it works on any automatic and is fairly expensive. An
advantage is that it can also flush out the transmission cooler.

> I mean really, there is no reason you ever really need to replace
> an automobile. It's not like the operating system gets upgraded
> or you have to run new software. There's no shortage of
> replacement parts. They certainly don't slow down or can't run on
> new roads. A car is like Rock & Roll. Nobody is inventing anything
> new, it's just variation on a theme.

That about as wrong a series of statements ever made!

My first car, a 1930 Model "A" Ford, had mechanical brakes, was rated
by the EPA as the dirtiest car ever tested, had no seat belts, air
bags, impact bumpers, etc. etc. and a top speed of around 45mph. I
sure wouldn't want to drive it on todays roads in todays traffic. I
like power windows, radio, power steering, anti-lock brakes and all the
other stuff that goes with having a newer car.

As for your comment "no shortage of replacement parts" that's just got
to be a joke, you can't possibly be serious. Manufacturer's
discontinue parts as soon as legally allowed to do so (used to be 10
years, I think it's 7 now) and there will be *no* aftermarket parts
unless the car was a big seller.