Question on 2003 mustang 4R70W swap into 94 sc

92bird

Registered User
For those of you who have swapped a newer v6 mustang 4R70W into your 94 or 95 SC I have a question:

Did any of you actually use the tq converter out of the mustang?? If so, does it stall higher than the factory '94 SC converter?

I just bought a '94 SC with a bad trans, and also bought a low mileaged 2003 4R70W and tq converter to go with it.

I heard in 03 the oem converters became stronger, so i'm hoping its up to the task of a nearly stock SC.

Thanks,

Jeramie
 
You can use the converter, it will fit just fine. You will have to completely dismantle the transmission to install your output shaft however, You need to modify the TCC solenoid and repin the harness. I suggest going to a markVIII flexplate and an 11&1/4 diameter converter, the weight reduction and stall increase makes a wonderful combination on these cars. If ford would put a good clutch in the OEM converters the late model 11&1/4 units would be perfection.
Alan
 
Thanks Alan. I knew the output shaft would have to be swapped. I have a spare '98 output shaft i will use. It will cost me some gaskets, etc.. But i got this trans locally for $300 with 44k miles on it. Only other trans i found locally was a '99 with 90k miles for $700..

I think i got a good deal on the trans, and i've built several of them now. Not too worried about the output shaft swap.

This SC will be a daily driver for my Girlfriend, and it will pretty much remain stock.

Glad to hear the 03 converter will do ok. Do you think it will stall any higher?

I had a 4R70W in my '92 SC with a stand alone controller, and used the 04 mach 1 torque converter and flex plate. The stall was nice. I've since sold that setup to a local guy and returned the '92 to a stock 5 speed.

Thanks for the help,

Jeramie
 
whats this about swapping the output shaft?

i installed a 2001 v6 trans, reused my stock convertor. all i did was swap out the external electronics and the tcc solenoid inside, repinned the harness and installed it in the car. works great, shifts much nicer now.
 
The 03+ 4R70W's do not use a VSS sensor, and therefore have no speedometer drive gear.
 
The 03+ 4R70W's do not use a VSS sensor, and therefore have no speedometer drive gear.

The 03's may or may not have the correct shaft as it was a running change for that model year. As for the convertor I gave away the one that came with my 03 model trans but from what I could tell from his car it stalled little if any higher than stock.

Charles
 
I wouldnt use that spare 98 Output shaft either .. you need one with the 7 tooth from a 97 or earlier.

- Dan
 
so that must explain why my 94's speedo reads ~10mph off...

any way to fix that without dismantling the transmission? or pulling it out again for that matter..... :eek:

fwiw, i do have a moates QH system.
 
so that must explain why my 94's speedo reads ~10mph off...

any way to fix that without dismantling the transmission? or pulling it out again for that matter..... :eek:

fwiw, i do have a moates QH system.

Change the speedo gear. Look at the FAQ's from the home page and input your specs, then order the proper gear.:) I assume the 01 modle trans you have uses the 8 tooth drive gear, since the earlier cars use the 7 tooth.
 
I wouldnt use that spare 98 Output shaft either .. you need one with the 7 tooth from a 97 or earlier.

- Dan


I also have the speedo gear from the 98 mustang v6, which i believe had 3.27 gears.

If I use the 98 output shaft and the matching 98 speedo gear will that work?

Jeramie
 
so that must explain why my 94's speedo reads ~10mph off...

any way to fix that without dismantling the transmission? or pulling it out again for that matter..... :eek:

fwiw, i do have a moates QH system.

Buy a speed cal from Dallas mustang, it's around hundred bucks and can correct for any gear ratio.
I ran my car with 4.10's 8 tooth output shaft and the speedo gear for 3.31's and wass able to correct without issue.

Charles
 
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92bird - Ive only done the swap twice on LX 4.6 Tbirds with an 00 GT trans 8 tooth shaft and the correct speedo gear, Speedometer seemed to work within reason, but there was a problem with the EEC hitting the rev limiter before the shift was commanded at WOT. I had to J-mod it and open up the holes a little bitter to make up for the difference so the car shifted before the rev limiter .. but slightly different application.

Sinhumane - as long you you dont have problems like I mentioned above, and your speedo is only off .. which speedo gear are you using BTW ? Your QH should be able to make up for that, but I dont know for sure.

- Dan
 
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