Shifting question
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Freshman User
Joined: Mar 2003
Posts: 42
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From: Newport News, VA
Shifting question
I have a 98 3.0 2WD AUTO and lately it seems that when I am driving with my cruise at 45 MPH the trucks shifts in and out of O/D for a split second. I thought it was my cruise control switch but when I drove it this morning without the cruise control on it still felt like it shifted in and out of O/D. I went through some of the threads already and I am not getting any indication of a faultly sensor but I am wondering if the speed sensor is going out. I went to NAPA's website and they show two different types of speed sensors so I am a little confused as to which one should be replaced. When I drive over 55 MPH with the cruise on I cannot tell if the problem is happening because of the road surface. I am going to try and drive it at 45 MPH tonight with the O/D turned off but I want to get an opinion on the sensors too. Thanks.
Fleet Mechanic
Joined: Feb 2007
Posts: 1,716
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From: Boston, MA
I have a 98 3.0 2WD AUTO and lately it seems that when I am driving with my cruise at 45 MPH the trucks shifts in and out of O/D for a split second. I thought it was my cruise control switch but when I drove it this morning without the cruise control on it still felt like it shifted in and out of O/D. I went through some of the threads already and I am not getting any indication of a faultly sensor but I am wondering if the speed sensor is going out. I went to NAPA's website and they show two different types of speed sensors so I am a little confused as to which one should be replaced. When I drive over 55 MPH with the cruise on I cannot tell if the problem is happening because of the road surface. I am going to try and drive it at 45 MPH tonight with the O/D turned off but I want to get an opinion on the sensors too. Thanks.
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
Watch the Tach & if it's the torque converter unlocking, the tach should show an increase in rpm if it unlocks.
Does it only do this when it's on a grade & the engine is under load???? I know where you are it's mostly flat, but at 45mph & in OD, it doesn't take much to lug the engine & at some point the computer will unlock the torque converter to prevent lugging the engine.
OR, maybe it's a misfire, as excessive spark gap can occur in as little as 30K miles with the OEM single platinum plugs & an engine lug could blow the spark out on a plug, or wire thats not up to snuff.
Does the cruise control ever randomly drop out, or the speed-o act up, or the ABS light flash when this happens???? If so, the speed sensor belongs on your suspect list.
If you come to suspect the speed sensor, as has been said, it's on the upper front center of the rear differntial. One 10mm hold down bolt & electrical connector to remove.
Fastner torque is 25-29 ft/lbs.
More thoughts for consideration.
Let us know what you find.
Does it only do this when it's on a grade & the engine is under load???? I know where you are it's mostly flat, but at 45mph & in OD, it doesn't take much to lug the engine & at some point the computer will unlock the torque converter to prevent lugging the engine.
OR, maybe it's a misfire, as excessive spark gap can occur in as little as 30K miles with the OEM single platinum plugs & an engine lug could blow the spark out on a plug, or wire thats not up to snuff.
Does the cruise control ever randomly drop out, or the speed-o act up, or the ABS light flash when this happens???? If so, the speed sensor belongs on your suspect list.
If you come to suspect the speed sensor, as has been said, it's on the upper front center of the rear differntial. One 10mm hold down bolt & electrical connector to remove.
Fastner torque is 25-29 ft/lbs.
More thoughts for consideration.
Let us know what you find.
