> Hi all, have an 87 convertible with the manual 4+3. When I press the button
> to activate the OverDrive, the light comes on the dash but it doesn't
> engage. The RPM's stay where there at. Also, while slowing down in second
> gear the tranny pops out of gear occassionaly?? I seriously doubt the
> previous owners ever changed the transmission fluid.. the car has 41k miles
> on it... any thoughts as to what might be the issue and how to correct?
> Any help would be greatly appreciated.
I would think the tranny pop could be solved with a rod adjustment.
As far as the OD, change the oil AND FILTER right now, and do it every
year. Couple be a couple of things with the OD. Here's how it works:
When you press the button, it's a momentary switch that sends a signal
to the ECM telling it to toggle the current state of the OD. The ECM
determines if it should be on or off, and sends that signal to the
overdrive relay. When the relay energizes, it energizes, the light
comes on the dash, and it energizes a solenoid in the valve body of the
transmission. A valve body is just hydraulic "switches" that open
and close to route the transmission oil to the proper path to put it in
the gear required.
Since the light is coming on, we know the switch, ECM, and relay is
working. The question is: Is the signal getting to the solenoid. If
yes, is the solenoid switching? If no, then there could be debris in
the solenoid that is preventing it from moving. The solenoid is just a
piston in a cylinder (it's only about 1/2" in diameter, if I remember
right), that is spring loaded. >> Stay informed about: doug nash 4+3 help please