'Is 1986 a decent year for Corvettes?
Are there characteristic problems with 1986 Corvettes I should watch
for? Is this car reasonably realiable?
I could buy now, or wait a year, save a few bucks and start looking at
early 90's Corvettes, is that a better plan?'
REPLY: Watch out for the 4 plus 3 manual trans. in late 1980's vettes ;
they were only out for 2 years due to the enormous problems and silly
engineering with them. If i were you, id definitely opt for an early
1990's Vette with LT1 motor which is durable ,more power., and better
for resale. Good improvements were had on Vettes after 1988 and i
think youll be happier going with an early 1990's .
Close, but not quite.
The Borg Warner second version T-10 four speed (known to many as the Super
T-10) or ST-10, was used during the mid to late 70s in Corvettes, as well as
other vehicles. Borg Warner had some problems, and Doug Nash acquired the
rights to the ST-10. This may be one of the reasons for no 4 speed 1982
Corvettes, but I am not sure.
Corvette needed a manual and they needed an overdrive with the fuel economy
issues. Doug Nash offered a solution, his newly acquired Borg Warner-based
ST-10 with an electronic overdrive on the rear tail housing. This type of
design had been used in several cars before this.
Doug Nash pulled a bit of a switch by using essentially an automatic
transmission on the tail of a manual transmission. It worked, it solved the
problem, and had potential to be great, but issued came up with the
automatic section. See http://www.5speeds.com/dne.htm for more information.
The DNE 4+3 was a good idea in a cobbled design. It became available around
mid production in MY 1984 and ran through 1988. In 1989, the ZF six speed
became the available manual transmission as option MN-6. BTW, there is no
such option ZF-6 which means a 6 speed transmission.
The basic ST-10 which is the main part of the 4+3 transmission is still
available through Richmond.
If you look at their web page, you will see their line of Australian right
hand drive transmissions. (Kidding, they have mirror images posted by
mistake - sloppy web work.)
The 4+3 transmissions are not as good as the six speed, but they are not a
terrible thing with enormous problems. Once rebuilt by some of the
specialized rebuilders now, you can expect long and good service from them.
While many lean towards the LT1, the first couple of years had problems with
the Opti Spark which is expensive. Not all have, as there are owners who
claim to still be running their original, however, it is more often to be a
Possibly the best choices are the '89-'91 L98 with the six speed or the '95
and '96 if you want the manual transmission cars. While the 700R4 automatic
has its own weaknesses, they are typically a $1400 rebuild to get them into
good condition and have plenty of service. The later ones are the best, of
course, however, the early ones most likely have been rebuilt by now and
should be as good.
I have a '93 40th anniversary coupe, and Tom is correct. I had to replace
the opti and yes it cost too much. Still, the original lasted 10 years and
77K miles, so the design isn't totally worthless. I expect (hope) the
current one will last my lifetime. I replaced it with a vented version from
a later year ,which maybe will solve the issue of condensation in there
rusting the cap. Apparentlly the rust got so bad it was floating around and
causing havoc with the cylinders firing. The damn thing sits under the
water pump, and in addition to that, the car spent its first seven years in
Salinas, California (near the ocean, not the desert).
As for the ZF six-speed, it is a pretty rugged trans. IMO first gear winds
out a bit too soon, but thanks to the LT-1 the low end grunt in second,
third and fourth is great. Fifth has decent acceleration at highway speeds,
sixth is for fuel economy only. I might mention that I installed a device
that defeats the 1-4 skip-shift "feature".
For anyone who's interested, I recently ordered a Corsa Power Pulse exhaust.
Not installed yet. Is there any compelling reason to keep the original?
That is, after I install the new system and decide I like it and don't want
to switch back.
'93 Ruby coupe, 6 sp (both tops)
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