ok currently i have 98GT motor and tranny (auto) and im in the middle of swapping in a 2003 motor and tranny (auto). i did my research for what i need on the motor swap. I plan on using my 98' wiring harness and 98' computer. now my problem is.... will my 98' harness and computer work with the 03' tranny. the reason i ask is because the 03' tranny is control thru the computer for the speedo and my 98' i have a small black gear inside the tailshaft of the tranny to adjust my speedo correctly because i have 3.73 gears. i looked inside the side of the 03' tranny and dont see a gear on the shaft to grab onto my speedo gear to control the speedo. will the speedo work correctly?? will the tranny even shift at all because of the difference?? i really need all the help i can $$ is tight and this my daily driver. please all advice would be greatly appricated
03' motor and tranny swap with 98' GT PLEASE HELP!!!
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wmburns
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Expect problems if the 98 uses an Vehicle speed sensor (VSS) sensor. I am positive the 2003 uses an Output speed sensor (OSS). The two sensors work completely different and are NOT compatible with each other.
The issue is further complicated because Ford changed the number of teeth used in the OSS sensor along the way. So that means you could have two transmissions both with OSS sensors that will not interchange. Note, the number of OSS teeth can be resolved via a custom tune.
Some ppl have reported using a special version of a Speedcal to convert OSS to VSS. However, the last post I remember reading stated he could not get it to work. Of course not everybody will go back and update their posts when an answer is found. I believe the OSS/VSS Speedcal is not a common unit. Expect some trouble if attempting to locate one.
If the issue is not resolved, the speedometer will not work AND the PCM will not know the car's true speed. This will mess up such things as fan speed selection. But most importantly since this is an electronically controlled automatic transmission, an incorrect car speed with totally mess up the gear selection.
It may be possible to transplant a VSS to an OSS transmission. However, expect that some disassembly will be required. I have never done this so I do not have any direct experience. Suggest enlisting the help of a transmission expect if this is the route you choose.
The issue is further complicated because Ford changed the number of teeth used in the OSS sensor along the way. So that means you could have two transmissions both with OSS sensors that will not interchange. Note, the number of OSS teeth can be resolved via a custom tune.
Some ppl have reported using a special version of a Speedcal to convert OSS to VSS. However, the last post I remember reading stated he could not get it to work. Of course not everybody will go back and update their posts when an answer is found. I believe the OSS/VSS Speedcal is not a common unit. Expect some trouble if attempting to locate one.
If the issue is not resolved, the speedometer will not work AND the PCM will not know the car's true speed. This will mess up such things as fan speed selection. But most importantly since this is an electronically controlled automatic transmission, an incorrect car speed with totally mess up the gear selection.
It may be possible to transplant a VSS to an OSS transmission. However, expect that some disassembly will be required. I have never done this so I do not have any direct experience. Suggest enlisting the help of a transmission expect if this is the route you choose.
I have one of those extended range speedcals, but I cannot get any support for it. I am basically stuck with the settings that are on they. I am glad it works. There is a guy on here, I think something like TriBlkCobra or something like that; he helped me a long time ago. (6 years ago)
I have a 01+ T45 in my 1996 GT.
I have a 01+ T45 in my 1996 GT.
okay, im stuck at work and my mechanic is doing the swap now and he said there is a sensor on the side of the transmission and with the sensor off of my 98' gt the tranny plugged into the 03' wont turn, but the one from the 03' tranny hooked up with my orginaly 98' harness stays stuck in park. Please any words of advice??
Mr. Rustypwnz
Advanced Member
Mr. Rustypwnz
Advanced Member
its called the extended range speedcal, its $100 from dallas mustang..
or he could convert the t56 to a manual gear drive speedo i believe and then it would plug in like stock..
just cleaned up and we had to roll my car out of the shop, but the motor fires up just fine, but now here is the issue
on the left side of the transmission (towards the middle) there is a sensor, my mechanic said it was some type of transmission speed sensor. now with sensor from my 98' inside the transmission it would plug in of course because im using the 98' wiring harness and computer, but with it inside the transmission it would not allow the output shaft to turn. so we removed the sensor and put the 03' sensor in the transmission and the it turned just the plugs were completely different plugs.
what are my options? list my possible ones if you can? if i cut the plug off the 03' harness and just solder the 2-pin connector to it then i can use my 98' harness will that work? if so will it work correctly?
now with the extended rang speedcal from dallas mustang...would that fix my speedometer problem? im kinda confused with all of this so could you just help explain it out a little for me with this whole swap i have so much stuff running through my head im gettin confused some so that would be great!! thanks alot again for all the help! i really wanna get the car running and driving and shifting properly ASAP
on the left side of the transmission (towards the middle) there is a sensor, my mechanic said it was some type of transmission speed sensor. now with sensor from my 98' inside the transmission it would plug in of course because im using the 98' wiring harness and computer, but with it inside the transmission it would not allow the output shaft to turn. so we removed the sensor and put the 03' sensor in the transmission and the it turned just the plugs were completely different plugs.
what are my options? list my possible ones if you can? if i cut the plug off the 03' harness and just solder the 2-pin connector to it then i can use my 98' harness will that work? if so will it work correctly?
now with the extended rang speedcal from dallas mustang...would that fix my speedometer problem? im kinda confused with all of this so could you just help explain it out a little for me with this whole swap i have so much stuff running through my head im gettin confused some so that would be great!! thanks alot again for all the help! i really wanna get the car running and driving and shifting properly ASAP
Mr. Rustypwnz
Advanced Member
yes the speedcal will fix this, your going from a mechanically driven electronic pickup, to a magnetic trigger wheel sort of, kind of like a crank sensor, so you will use the 03 cobra pickup unit, and wire it into the extended range speedcal. and it will work like stock..
oh and post up some damn pics!!!
oh and post up some damn pics!!!
the speed cal with not work for my application, i contacted dallas mustang and talked to the guys over there and they said only on manual transmissions it will work NOT on the automatics...
but i did alot of reasearch and call alot of people today and i found a donor car, its a 2002 GT and its and auto... i was gonna get the computer,speedo and dash harness and swap with mine and have sniper tuning adjust my PATS and fuel line setup.
but one thing i was told that for the computer i can use an 02' computer as long as its an automatic, but my motor and tranny are 2003
and someone told me to rather get all my parts from the same car and not all different cars because sometimes the speedo's wont work with a different harness even tho 99'+ are the same but a lot of people said find an 03'-04' computer but like i said i found a 02' with 25k miles on it to use for my swap
this seems like a lot of work but easier than swapping a tail-shaft which i was told that's not worth it!
but i did alot of reasearch and call alot of people today and i found a donor car, its a 2002 GT and its and auto... i was gonna get the computer,speedo and dash harness and swap with mine and have sniper tuning adjust my PATS and fuel line setup.
but one thing i was told that for the computer i can use an 02' computer as long as its an automatic, but my motor and tranny are 2003
and someone told me to rather get all my parts from the same car and not all different cars because sometimes the speedo's wont work with a different harness even tho 99'+ are the same but a lot of people said find an 03'-04' computer but like i said i found a 02' with 25k miles on it to use for my swap
this seems like a lot of work but easier than swapping a tail-shaft which i was told that's not worth it!
Mr. Rustypwnz
Advanced Member
oh man, damn i thought you were putting a 03 cobra engine into the car, damn ive been smokin some good stuff lol.. my bad on that one..
sounds like you got it figured out though!!
sounds like you got it figured out though!!
well **** lol if money wasnt tight it would be an 03' cobra motor but i started this swap ALL bc of my tranny took a dump and i didnt wanna have it rebuilt for $1200 bc i found a 03' 4.6 motor and tranny with 9k miles for $1500, alot of stressful days but day by day im trying to figure it all out.
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