4r70w tranny swap , 50 miles later, I lost O/D .
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4r70w tranny swap , 50 miles later, I lost O/D .
In need of some educated, straight to the point advice . Ive spent countless hours reading forums and I feel more lost now then before .
My son has a 01 F150 2wd 4.2 V6 with a 4r70w.
He bought it used and we pieced it together to get it rolling . Since day one the O/D never engaged . He'd start the truck , hit the O/D button and run 4000 RPM everywhere he went for the past year.
He just graduated high school and got some gifted cash from family and decided to spend it fixing the ol truck.
We pulled a tranny out of a 95 mustang 3.8l with 89,000 miles on her .
As mentioned , I've got more time in reading then I do in labor at this point .
We pulled his tranny out and started swapping parts .
- hardwired electronics to circuit board electronics
-The shift arm from a car to a truck - The Tailshaft from mustang to f150
- The slip yolk from mustang to F-150
- The 9 pin bulkhead to a 7 pin bulkhead
I believe that's it , everything from the prior F-150
tranny that wasn't the same on the mustang tranny we just swapped the parts .
Everything but the Torque Converter. My son managed to strip and round off 3 of the 4 nuts on the flex plate . Was originally going to use the Torque Converter that came with the new tranny , but after reading , I got the impression that I should keep the old Torque Converter on there anyways .
So that's what we did , drained and refilled the original torque converter and put in the new tranny.
Everything was working beautifully.
For the first time since he's owned that truck it went down the road , shifted through every gear and did so running 1000 - 1500 rpms like a normal truck .
50 miles later , we now have the same exact issue as the original transmission.
Hit the gas , shifts to 2nd , accelerates and right when it's suppose to hit 3rd , it goes into neutral.
Hit the O/D button , she downshifts and keeps on trucking @ 4000 rpm .
Have I ruined the new / used tranny ?
Should I have switched that torque converter or bought a new one ?
I got one code , can't remember the exact number but I'm pretty sure it said Speed Sensor Circuit Malfunction or something close to that .
Anybody got a straight forward answer for me ?
My son has a 01 F150 2wd 4.2 V6 with a 4r70w.
He bought it used and we pieced it together to get it rolling . Since day one the O/D never engaged . He'd start the truck , hit the O/D button and run 4000 RPM everywhere he went for the past year.
He just graduated high school and got some gifted cash from family and decided to spend it fixing the ol truck.
We pulled a tranny out of a 95 mustang 3.8l with 89,000 miles on her .
As mentioned , I've got more time in reading then I do in labor at this point .
We pulled his tranny out and started swapping parts .
- hardwired electronics to circuit board electronics
-The shift arm from a car to a truck - The Tailshaft from mustang to f150
- The slip yolk from mustang to F-150
- The 9 pin bulkhead to a 7 pin bulkhead
I believe that's it , everything from the prior F-150
tranny that wasn't the same on the mustang tranny we just swapped the parts .
Everything but the Torque Converter. My son managed to strip and round off 3 of the 4 nuts on the flex plate . Was originally going to use the Torque Converter that came with the new tranny , but after reading , I got the impression that I should keep the old Torque Converter on there anyways .
So that's what we did , drained and refilled the original torque converter and put in the new tranny.
Everything was working beautifully.
For the first time since he's owned that truck it went down the road , shifted through every gear and did so running 1000 - 1500 rpms like a normal truck .
50 miles later , we now have the same exact issue as the original transmission.
Hit the gas , shifts to 2nd , accelerates and right when it's suppose to hit 3rd , it goes into neutral.
Hit the O/D button , she downshifts and keeps on trucking @ 4000 rpm .
Have I ruined the new / used tranny ?
Should I have switched that torque converter or bought a new one ?
I got one code , can't remember the exact number but I'm pretty sure it said Speed Sensor Circuit Malfunction or something close to that .
Anybody got a straight forward answer for me ?
Senior Member
Joined: Jun 2010
Posts: 16,607
Unfortunately, there are no just abouts when it comes to transmissions and the electrical/electronic controls that make them work correctly.
There (and we say "could" be a problem with the valve body) because certain checks need to be done and shooting in the dark doesn't accomplish a lot sometimes.
We don't know the history of the trans that was eventually installed and when we start mixing parts, ,,,well,,,,,, no need to go any further.
Different years have different controls and to disregard those , we can sometimes come up with problems nobody expected.
Anybody with trans experience would back away from ths project because we created so many opportunities for problems.
There (and we say "could" be a problem with the valve body) because certain checks need to be done and shooting in the dark doesn't accomplish a lot sometimes.
We don't know the history of the trans that was eventually installed and when we start mixing parts, ,,,well,,,,,, no need to go any further.
Different years have different controls and to disregard those , we can sometimes come up with problems nobody expected.
Anybody with trans experience would back away from ths project because we created so many opportunities for problems.
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