84 Camry Transmission won't shift into overdrive

[virus-script]

hi people i have a 1984 camry (197,000 miles) and am having a little trouble. ok one day i decided to degrease my engine and make it look a little cleaner. later on that night when i was driving home on the freeway i noticed my car will not shift into overdrive (at 70 mph i am hitting about 4000 rpms). i have no idea what the problem can be. the o/d off light comes on when i push the button on the shifter to turn it off so the button is working ok. I do have a small leak coming from the tranny (dont know where yet) but it looks to me the fluid is ok even though it is very difficult to check due to the hot/cold marker on the stick. i also have replaced the shifter cable in the past with one from the junkyard about 6 months ago but everything seemed fine then. does anyone have any ideas what the problem might be? this is my daily driver and i want to try to fix the problem b4 taking it to the shop and having them charge me and arm and a leg for what could be an easy fix.

[idmetro]

My 91 exhibited similar behavior at 168,500 miles after suffering extreme neglect. Have you serviced the transmission (fluid and filter change) recently? I also noticed that mine was VERY sensitive to the fluid level. Unfortunately in my case the damage was done so I ended up changing the transmission with a JDM one that I bought on ebay. I would try a fluid and filter change first.

[Brian R.]

Not shifting into OD may be caused by a bad engine thermostat.

[virus-script]

i actually think i have found he problem after all. i believe it is an electrical wire that runs over the transmission (o/d is an electrical gear. probably snapped when i was degreasing the engine. i will fix it tomorrow and further update u. yes i have maintained my transmission pretty well. i keep 2 gallons in my trunk because of the small leakage but that will be fixed soon also once i find the problem and find time to do it. thanks for the suggestion though i was hoping to finally get a response

[virus-script]

yes and my engine thermostat can be a little tweaked out at times but lately it has been ok. if that wire doesnt fix the problem i will replace that too. thanks man.

[Brian R.]

Good luck

[evhgame]

How does an engine thermostat have anything to do with an overdrive option? Theres only one thermo and thats one for the coolant system. The auto tranny coolant lines dont even go through the thermo, its a direct line from the radiator and has its own recirulation method which is seperate from the actual engine.

Ive looked at it and there is a 2 wire set that has a broken wire. The wire leads into the area of the tranny, most likely a switch in the tranny that turns on the overdrive. The light comes on for the OD yes, but thats purely engine electrical harness right there.

The overdrive is a completely electronic switch that turns the car into its 4th gear. As far as I know, overdrive is not even around in newer vehicles, they just call it what it is, a 3, 4, 5, or 6 speed tranny.

[Brian R.]

I am not sure about the '84, but all newer models that I am aware of have a lock-out for the OD if the engine is not hot. If the thermostat doesn't close, the engine never gets up to temperature and the OD will never engage.