E4OD overdrive issues
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Mountain Pass
Joined: Feb 2020
Posts: 101
Likes: 7
E4OD overdrive issues
So long story short, I put a new transmission in my 97 7.3 and it's having problems with OD. I took it to a shop and had it scanned and the transmission was throwing no codes and my OD light doesn't flash. The problem I'm having is that no matter what, OD will hit at exactly 30 mph no matter how much I'm in the throttle. If I'm barely in it then it's not a problem, but say I smash the gas and the RPMs carry out it'll still slam into OD right when it hits 30 and it slams hard. Also, under light throttle it shifts fine but it kind of jerks the truck forward and backward like some kind of shutter. It also does this stuff when downshifting. If I'm in torque converter lockup at low speeds around 35-40 and smash the throttle, the downshift to OD is harsh and the truck jerks around. I've replaced the speed sensor on the rear diff, new neutral safety switch and its adjusted right. I've gone through all grounds and ground straps they're all tight and not damaged. The only other thing is that my speedometer twitches around so could that be it. I'm about ready to take it to a shop, any help is appreciated
Cross-Country
Joined: Aug 2021
Posts: 77
Likes: 19
Have you checked the wiring to the Vehicle Speed Sensor (VSS) in the rear diff? The air gap between the sensor and the tone ring may not be right. I was having some issues with my speedo jumping around a bit and kicking me out of cruise control on occasion. I replaced the VSS and that has improved my issues somewhat. The speedo still bounces a bit but it hasn't been kicking me out of cruise control.
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Mountain Pass
Joined: Feb 2020
Posts: 101
Likes: 7
Have you checked the wiring to the Vehicle Speed Sensor (VSS) in the rear diff? The air gap between the sensor and the tone ring may not be right. I was having some issues with my speedo jumping around a bit and kicking me out of cruise control on occasion. I replaced the VSS and that has improved my issues somewhat. The speedo still bounces a bit but it hasn't been kicking me out of cruise control.
Cross-Country
Joined: Aug 2021
Posts: 77
Likes: 19
I'm not sure where you live but rust is a big problem where I live. And I've seen rust jacking between the sensor and the differential housing which increases the air gap. If that's occuring on your truck then you may want to remove any rust there.
Hotshot
Joined: Jul 2020
Posts: 10,533
Likes: 2,660
From: Near Salt Lake City
If the rear diff speed sensor checks out
Check the one on the trans or transfer case that runs the speedo
A faulty one can also affect the shift patterns That one on the trans is actually the VSS and the one on the rear axle is the rear abs sensor
Either way they both need to work or you got trouble
Hopefully your new trans is good (valve body)(OD clutch piston etc)
Check the one on the trans or transfer case that runs the speedo
A faulty one can also affect the shift patterns That one on the trans is actually the VSS and the one on the rear axle is the rear abs sensor
Either way they both need to work or you got trouble
Hopefully your new trans is good (valve body)(OD clutch piston etc)
Mountain Pass
Joined: May 2012
Posts: 137
Likes: 7
I just ran into something similar turned out the TPS on the accelerator pedal was the culprit, replaced with a Dorman look alike and all is well, I too replaced both the ABS sensor and transmission speed sensor to no avail, ended up destroying the OD gears in the transmission before I tracked down the problem, if the ABS sensor on the rear end is faulty it will give speedometer issues, but if the truck is actually not shifting properly it could be simply responding to input.
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