1991 Dynasty - Various Questions

I just bought a new vehicle, and now I need to decide if I am going to keep
the 91' Dynasty as my commute vehicle or if I am going to get rid of it.

The Dynasty has transmission issues, but beyond that, it runs well. It has
120,000 miles on it. I am debating spending money to fix the transmission,
but I am not certain how many trouble free miles I can expect out of the
Dynasty on a go-forward basis?

The automatic transmission upshifts and downshifts rough between 1st and
2nd, and 2nd and 3rd gear. It works fairly well in the morning when it is
cold, but the shifts get rougher as it warms up. I recently had the
transmission oil and filter changed - the mechanic indicated there were no
metal filings to speak of. It shifted almost perfectly for a couple days
after the oil change, and then it got worse than it ever was. Fortunately,
it has improved slightly in recent weeks, but there is little doubt there is
a problem. Based on this vague information, can anyone suggest to me what
the nature of the problem might be, and the possible range of costs involved
to fix it?

Thank you,
Chris

 

If it shifted fine, and got worse after the servicing I would suspect that
there is the wrong tranny fluid in it. I would have them drain and refill
with the correct fluid, ATF+3.

 

Thank you,

It was shifting terrible before the fluid change - after reading all the
newsgroups, I thought it was worth a shot, but in my case, it only solved
the problem for a couple days. It makes me wonder if there isn't something
"loose" in the transmission clogging some of the ports, and the fluid change
was enough to dislodge it temporarily....

Any thoughts on what it could cost to get them to do a tear down and an
inspection/adjustment?

Chris

 

Sounds like dirt to me. If this is a three-speed, as I recall the valve body
needs to be removed and cleaned. The fluid change might have stirred things
up.

 

Thank you,

It is a 4 speed. The shift from 3rd to 4th has always been fairly smooth,
so I didn't mention that earlier.

Chris

 

Well, if you got 120k out of the first transmission, you'll get about
that much out of the next (more if the rebuilder upgrades it with newer
parts). The engine should last over 200k pretty easy.. The plastic
interior bits and pieces will start to fail on these cars before
anything major mechanical (other than the trans).

 

Not likely- but again you should be SURE that it has the correct fluid
in it (and I'd recommend ATF+4 over ATF+3) before tearing into it.

There's nothing to "adjust" in the electronic 4-speeds. All "adjustment"
is done when the clearances in the clutch packs are set during assembly,
then the computer takes it from there and compensates as parts wear. A
"turnkey" rebuild runs in the neighborhood of $1000-$1500. Less if you
R&R it yourself.

 

I also forgot to mention that any transmission shop should hook this
unit up to their diagnostic scan tool. They can then read the clutch
volume indices from the computer and get a very accurate estimate of how
worn the clutch packs are. It won't identify hard failures like broken
snap-rings, and it won't identify incorrect fluid, but it will give an
indication of the overall health of the friction materials.

 

With regards to transmission work, am I better off going to a dealer, or to
a transmission shop?

I had the transmission oil changed at a dealership - would they put anything
but ATF3 or ATF4 in the car? I did insist to the guy making up the ticket
that they use ATF3, but I didn't see what they actually put in the car.....

Chris