No overdrive

[1995 Mark VIII]

Today I was driving down the on-ramp to the freeway and my car would not go into overdrive. Anyone know what it might be?

 

[1995 Mark VIII]

I just drove it right now and it went into overdrive. Is there a solenoid switch for the overdrive? If so, could it be going bad?

 

[jbelcourt]

I don't know a lot about transmissions but I believe there is an overdrive band. You might be losing overdrive.

 

[Bangster]

What happened when it wouldn't shift, did it free wheel (rev up if you gave it gas) or not even try to shift to OD (just stay in D)? When I got my 97 if I let up on the gas at the D to OD shift, it wouldn't shift, it would rev up then drop into OD. I did the JMod and replaced some pretty worn valves in the VB and it is nearly perfect now, I thought for sure I was going to be swapping the transmission.

Test to see if it is the OD band or something else like the VB/main control:

while driving around 40-50 mph, select manual second gear and let off the gas, if the transmission "engages" and the rpms match what they should for second gear (fairly high, well above 800/1000 idle), and if you let off the gas and you have engine braking, then it probably isn't the OD band, and can be the vb/main control. Other obvious things to check are fluid level and condition.

If it free wheels and the engine drops to idle, and you have no engine braking, it is probably something related to the OD band.

 

[chris2523]

correct ^
if you have manual 2nd gear, ie, engine braking, the OD band is still there and the problem lies elsewhere.

valve body is a good guess.

 

[ford nut]

Check the wiring to the button under the console
http://www.lincolnvscadillac.com/tech/lincoln-mark-viii/overdrive-switch/index.htm

 

[Bangster]

Also an issue with the shift solenoids can cause this, I don't remember if it was 95 or 96 that got revised solenoids to help prevent issues.