I just traded my dirtbike for an 86 c4 with a manual 4+3 trans. The car is in great shape but the overdrive does not work. anyone have anything or ideas for me that i can try and do to get this thing to work before i buy a new one ore have it rebuilt. Any advice will be great

I just traded my dirtbike for an 86 c4 with a manual 4+3 trans. The car is in great shape but the overdrive does not work. anyone have anything or ideas for me that i can try and do to get this thing to work before i buy a new one ore have it rebuilt. Any advice will be great

Woah a dirt bike for a vette....
How come i cant find any deals like this......
As far as the tranny goes maybe try changeing the fluid's maybe somethings blocking it up i donno much about tranny's
But ive heard a guy with the same issue who changed it and it worked again so then again i donno but its worth a try!

the overdrive does not work.
There are steps to work through to determine what is wrong before considering a rebuild ($$$$)
Change O/d fluid and filter.
Then you have to work through the wiring to see if there is a fault there.
Is simple system;
power to a relay , then through a 1st gear lockout switch to O/d solenoid ; no biggy
Many 4+3's are showing problems with age / lack of maintainance but most come good with simple fixes

http://i171.photobucket.com/albums/u309/vetteoz/electrical/Od.jpg

Jesus!! I have a couple dirt bikes in my garage and I would trade them in a heart beat for a Vette!

You wouldn't happen to know what filter the od requires would you?

You wouldn't happen to know what filter the od requires would you?

Ecklers sells them and the pan gasket as a kit.

Ecklers sells them and the pan gasket as a kit.

Save your $$$
The OD filter is the same as the one used in Ford FMX trans
Go to local parts shop

CarQuest 85926
AC Delco TF-184
FRAM FT1024
NAPA ATP 14717
Ford D0AZ-7A098-A

Have to reuse your old filter gromment as Ford ones don't come with one
RTV works just as good as a OE gasket, just make sure pan rail is perfectly clean 1st

I agree with OZ, troubleshoot before you spend big bucks, most likely electrical problems, these circuits are simple, and the overdrives are bullet proof.
Consult a trusy tech if you dont know where to go with this troubleshooting.
I'm in 'Nebraska' if that helps any??

Is simple system;
power to a relay , then through a 1st gear lockout switch to O/d solenoid ;
Just one nit to pick here: On the '86 they did away with the 1st gear lockout switch. The ECM determines if you are in 1st gear starting in '86. Even simpler then!:thumbsup:

so what are the main electrical parts i need to check

so what are the main electrical parts i need to check
All in the circuit diagram above
Computer sends signal to turn O/d relay on ( light on dash should light up ) Relay supplies power to O/d solenoid as shown
Fluid/ filter change is 1st step as many operational problems related to low fluid

so what are the main electrical parts i need to check

The main problem is the 4+3 is the on/off switch on the shifter or in center console depending on the year. If it wont back up (no reverse) there's a big and expensive problem, get the dirt bike back...
David

The main problem is the 4+3 is the on/off switch on the shifter or in center console
I beg to differ.
The O/d should work automatically so if it is not coming on under the correct conditions then a electrical problem ( assuming it is mechanical sound ) would be in one of the areas I listed above.Switch only controls manual operation

The main problem is the 4+3 is the on/off switch on the shifter or in center console depending on the year. If it wont back up (no reverse) there's a big and expensive problem, get the dirt bike back...
David

David - I like reading your Tech Answers and reading about your experiences...but I just have to disagree with you on one thing SCREW THE DIRT BIKE....KEEP THE VETTE! LOL!:banana:

David - I like reading your Tech Answers and reading about your experiences...but I just have to disagree with you on one thing SCREW THE DIRT BIKE....KEEP THE VETTE! LOL!:banana:

Wayne - as much as I like reading any of the answers, I like your quote of the six time candidate for President of the United States from the socialist party. Isn't it so very profound? :patriot: Patriot too!

Wayne - as much as I like reading any of the answers, I like your quote of the six time candidate for President of the United States from the socialist party. Isn't it so very profound? :patriot: Patriot too!

Thanks Lee. It is VERY PROFOUND and I had to dig really deep to find the inner strength to quote a Socialist candidate from YEARS past. He was way ahead of his time...obviously. But in the end, there was no arguing his words, so I had to let it be quoted.:doh:

I beg to differ.
The O/d should work automatically so if it is not coming on under the correct conditions then a electrical problem ( assuming it is mechanical sound ) would be in one of the areas I listed above.Switch only controls manual operation

Even when the switch is stuck in the OFF position?
A 1986 Corvette with a early production date(iron heads with perimeter valve cover bolts) uses a 4+3 that is a piece of crap, In mid 86 they finally got the bugs fixed do work some what automatically, But a stuck on/off switch is just that.
David Steele