Problem with E4OD transmission!
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New User
Joined: Jan 2006
Posts: 8
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Problem with E4OD transmission!
I have been having this problem quite often and I cant figure it out so I will see if you can help me. The other day I was driving down the interstate at 70mph, with the cruise set on flat land. The engine rpm is about 1850 or so and then the rpms will jump for no reason to about 1950-2000rpms for about 1.5-2 seconds then go back to normal. I know it didnt downshift cause it would have jumped alot more rpms than 150-200. It isnt the cruise control cause it will do it when the cruise isnt on at all.And it will do it at all kinds of speed, and another thing that gets me thinking is it only starts doing it after the tranny get warmed up like 10 minutes or so. Maybe a sensor? The overdrive lights isnt flashing though, no lights are goin off. Any help would be GREATLY appericated.
Fleet Mechanic
Joined: Sep 2005
Posts: 1,509
Likes: 3
From: Ladner, British Columbia
E4OD Problems
1.0 Do you notice the truck actually jerking a bit when this happens or is the only symptom that your tachometer is jumping? (The jerk could be very faint, like a soft shift, or torque converter unlocking)
2.0 Do you have a secondary overdrive unit such as a US Gear Splitter or a Gear Vendor on your truck? The reason I am asking is that your rpm 1850 at 70mph does not add up even if you had a very low rear end ratio. Standard ratios are usually 3:55 or 4:10 if your truck is set-up for towing.
If your answer to both the above questions is no then I would suspect that your Tachometer sensor is starting to go bad. When this sensor starts to go the Tachometer starts to read funny and as this gets worse it eventually will cause shift problems and the OD light will start to flash.
If you are feeling a slight jerk then most likely the torque converter is locking and unlocking. Check to make sure your brake light switch is working properly as the torque converter unlocks each time the brakes are applied. Another sensor that could be causing the problem you are seeing is the Throttle position indicator. If it provides an erractic signal or shows a variable signal even so you have not moved your foot on the accelerator, you could get the torque converter to unlock suddenly. More common signs of a bad FIPL are hard shifts so and it should trigger the blinking OD light.
Hope this helps a bit.
Seb......
2.0 Do you have a secondary overdrive unit such as a US Gear Splitter or a Gear Vendor on your truck? The reason I am asking is that your rpm 1850 at 70mph does not add up even if you had a very low rear end ratio. Standard ratios are usually 3:55 or 4:10 if your truck is set-up for towing.
If your answer to both the above questions is no then I would suspect that your Tachometer sensor is starting to go bad. When this sensor starts to go the Tachometer starts to read funny and as this gets worse it eventually will cause shift problems and the OD light will start to flash.
If you are feeling a slight jerk then most likely the torque converter is locking and unlocking. Check to make sure your brake light switch is working properly as the torque converter unlocks each time the brakes are applied. Another sensor that could be causing the problem you are seeing is the Throttle position indicator. If it provides an erractic signal or shows a variable signal even so you have not moved your foot on the accelerator, you could get the torque converter to unlock suddenly. More common signs of a bad FIPL are hard shifts so and it should trigger the blinking OD light.
Hope this helps a bit.
Seb......
