Odd feeling coming from drive train
08-12-2014, 11:12 PM
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Odd feeling coming from drive train
Recently, a new vibration, or feeling has been coming from my drive train. It only happens on inclines, declines, or whenever the engine has to work harder than average (such as a heavy head wind). It feels like there is a lapse in the drive train where you can see that the engine rpm's are gong strong, but there's a momentary loss of power to the wheels. It causes about a half a second of coasting. This happens only between 35 and 45 miles per hour. Its an automatic transmission on a 1991 Ford Pickup.
I went through the gears, driving in first, second, and drive. I discovered that this phenomenon only occurs when I drive in the "drive/overdrive" gear and only when the overdrive mode is on, ready to be engaged. When I press the overdrive button to turn off the overdrive, this feeling goes away.
So, my first question is what this could be? I will be having the transmission checked next week when I take it in for an oil change, so I'll have an opinion from my local mechanic soon, but for now I would like to try to find out hat's wrong.
Also, could this be a sort of safety feature, telling me when to turn off the overdrive on inclines, declines, and when the engine is working harder than usual?
I'm ashamed to say, but no one in my family knows really what the overdrive does in a car, aside from having better gas mileage. Perhaps it's time I figue this out before I cause any real damage. Thus far, the truck has never pulled anything very heavy with the overdrive engaged, so I don't think I caused any fatal wear to the transmission.
Like I said, I'll know more when my mechanic takes a look at it next week. Until then, I'm driving it easy and with the overdrive off whenever I go up and down hills.
--James
I went through the gears, driving in first, second, and drive. I discovered that this phenomenon only occurs when I drive in the "drive/overdrive" gear and only when the overdrive mode is on, ready to be engaged. When I press the overdrive button to turn off the overdrive, this feeling goes away.
So, my first question is what this could be? I will be having the transmission checked next week when I take it in for an oil change, so I'll have an opinion from my local mechanic soon, but for now I would like to try to find out hat's wrong.
Also, could this be a sort of safety feature, telling me when to turn off the overdrive on inclines, declines, and when the engine is working harder than usual?
I'm ashamed to say, but no one in my family knows really what the overdrive does in a car, aside from having better gas mileage. Perhaps it's time I figue this out before I cause any real damage. Thus far, the truck has never pulled anything very heavy with the overdrive engaged, so I don't think I caused any fatal wear to the transmission.
Like I said, I'll know more when my mechanic takes a look at it next week. Until then, I'm driving it easy and with the overdrive off whenever I go up and down hills.
--James
08-14-2014, 09:05 AM
#2
Senior Member
Overdrive in your truck is a electronic selector solenoid. Lag time is not unusual when shifting in and out of OD. Later models worked just the opposite. You had OD all the time unless you put it in towing mode. After you have the truck serviced if it continues look at replacing the OD solenoid.