Purchased a 94 ford 150 120,000 miles on the clock. It has the four speed automatic. When the transmission fluid is cold all gears shift smoothly. It seems when the atf warms up the transmission wants to shudder or change back from one gear to another at around 40 to 50 mph. When I am running a steady 70 everything is fine. When going through town at 25 to 30 mph everything is fine. I checked the fluid level when the transmission was hot and the engine operating. The level is full and the fluid looked nice and red like new. I wonder if I have a sensor that is shot or could there be larger issues.
Rough shifting automatic tranny
- Thread starter RedOak
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Don't know about Fords but many vehicles use the TPS (throttle position sensor) in determing auto trans shifting. If the TPS is dirty right around the range where it is where you are having this issue, the TCU might be thinking you are hitting the gas periodically, so it downshifts.
4R70Ws are notorious for converter shudder. I feels like driving over a cattle guard. It occurs under light throttle at ~35mph.
The easiest fix is to replace all ATF, including draining the converter. Vehicles in warm climates benefitted from an aux trans cooler.
The easiest fix is to replace all ATF, including draining the converter. Vehicles in warm climates benefitted from an aux trans cooler.
Yep, I have no idea how many miles is on the Atf, but still looks good and has no burnt smell. Will try a total drain and replace with maybe durablend atf that is compatible with ford's specs.
Punisher is EXACTLY correct.
Use ONLY Mercon V! Don't use a Multi vehicle ATF if it isnt clearly stated its ok. But even then, I would use a real full on Mercon V. These transmissions are very tough but very sensitive with it comes to TC shudder. My crown vic had it when I first bought it. Buttery smooth when cold(1. the fluid is thicker 2. the TC does not lockup when cold). Mine was a darker red to.
I didnt drop the pan as I didnt have time during fall semester. I used a fluid evacuator instead and refilled it with Castrol Mercon V from AAP. Transmission is quick and smooth now. It will take about 150 miles to really feel the full difference though.
A note on the converter, yours may have a drain plug. Mine does. It is accessable when you pull that little rubber plug out.
Some advise to unplug the battery to reset the transmission's learning. I did NOT do that when I did it and had no ill effects. Some warn if you change the fluid and dont reset, you will get slipping. I didnt. Mine actually shifted noticably better immediately. Its full effect was felt about 1 week(130-150 miles) into driving. Firmer more confident shift points, and zero shudder.
Use ONLY Mercon V! Don't use a Multi vehicle ATF if it isnt clearly stated its ok. But even then, I would use a real full on Mercon V. These transmissions are very tough but very sensitive with it comes to TC shudder. My crown vic had it when I first bought it. Buttery smooth when cold(1. the fluid is thicker 2. the TC does not lockup when cold). Mine was a darker red to.
I didnt drop the pan as I didnt have time during fall semester. I used a fluid evacuator instead and refilled it with Castrol Mercon V from AAP. Transmission is quick and smooth now. It will take about 150 miles to really feel the full difference though.
A note on the converter, yours may have a drain plug. Mine does. It is accessable when you pull that little rubber plug out.
Some advise to unplug the battery to reset the transmission's learning. I did NOT do that when I did it and had no ill effects. Some warn if you change the fluid and dont reset, you will get slipping. I didnt. Mine actually shifted noticably better immediately. Its full effect was felt about 1 week(130-150 miles) into driving. Firmer more confident shift points, and zero shudder.
Heh heh, heh heh, heh heh, Ford.
Oh, wait. Honda's have transmission issues too.
Oh, wait. Honda's have transmission issues too.
The TC plug was removed around 1999/2000 production, IIRC, so yours should have it, unless it was replaced with one without the plug somewhere along the line.
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