FMX to 4r70w swap

[Robsweden]

Exhaust is done, just checking the angles on driveshaft

 

[Robsweden]

Im redoing the exhaust was not pleased. But now the front part is welded and ready

 

[Robsweden]

Today I finally finished the exhaust. New pipes all the way and welded. I cut out for the pipes in the Valance.

 

[Robsweden]

The Mach 1 has been out for a while now. The 4r70w is big improvment to the old FMX. Its so nice to Cruise the highway, but still smoke the tires when accelerating hard.

If someone has some questions Il be glad to help

[video=youtube]



Regards Rob

 

[RCH71]

Nice to know you are happy with it!! what is your rear gear ratio?

 

[Robsweden]

Nice to know you are happy with it!! what is your rear gear ratio?

Thanks Gear ratio is 3.5 and tires are 27.1 inch

 

[RCH71]

Nice to know you are happy with it!! what is your rear gear ratio?

Thanks Gear ratio is 3.5  and tires are 27.1 inch

Do you know what was the stock converter stall was? and the stall after the modification?

 

[Robsweden]

Nice to know you are happy with it!! what is your rear gear ratio?

Thanks Gear ratio is 3.5  and tires are 27.1 inch

Do you know what was the stock converter stall was? and the stall after the modification?

Hi

I Think it was 1800 and modified to 2300-2400.  Its hard to get a correct stall speed number because ford used different settings. But stock should be  1600-1800.

 

[AcesArneson]

Are your front tires 27.1" as well? Do you get any fender rub? Stock front suspension?

 

[mrgmhale]

Awesome Rob

[ If anyone is interested I can list the mods done in the 4r70w.]

I am!!

[il have to shorten the driveshaft 1,5-2 inches.]

Where will you let it be balanced?

In our case the tailshaft housing is the short one, so no changes needed to the driveshaft in our 73 Mach. The AOD length was only 1/4" longer with the short tailshaft than the C4. We had plenty of reserve travle with the sliding yoke at the front of the driveshaft. YMMV.

 

[mrgmhale]

Below are a series of YouTube links for our entire AOD transplant. In the descriptions I include parts list and vendor info as well.



This is a link showing the impact on engine RPM at 60 MPH with the AOD in 3rd/Drive gear, and then in 4th/OverDrive gear. In the AOD, 3rd gear is a 1:1 ratio, just like 3rd gear in a C4. FMX, or C6 automatic transmission.









Following is a list of relevant YouTube video links contained in this document’s prior paragraphs, and from YouTube listings:





















https://youtu.be/XZ7CkcY1vFQ



https://youtu.be/vdR-z3KV0UE



https://youtu.be/YCBBgd-olQ0



https://youtu.be/NcYr68atRjM



https://youtu.be/iFNXTGXNNcQ



https://youtu.be/2tTwnbcZZkY



https://youtu.be/8QncIKQTvNo



https://youtu.be/b4lnPReGWuM



https://youtu.be/zfYe--Gsjdk







Setting up Throttle Valve Pressure from the carburetor cabling, and how the original auto tranny floor shifter behaves with the AOD when shifting manually:



https://youtu.be/KYIAqqYUKNo

 

[Robsweden]

In our case the tailshaft housing is the short one, so no changes needed to the driveshaft in our 73 Mach. The AOD length was only 1/4" longer with the short tailshaft than the C4. We had plenty of reserve travle with the sliding yoke at the front of the driveshaft. YMMV.

I have SPC upper controm arm tires are 235/45/18 no rubs at all.

 

[mrgmhale]

Wow! That is very impressive that you are doing this yourself! I have watched a lot of videos on the rebuild process for a C4 and doing a rebuild on any automatic is not for the faint of heart! Switching to an AOD is on my wish list. Is there enough room for the new trans in the tunnel? are there mods that need to be done? Some information I have read says it bolts right in and others say it requires mods. Great Job!

We popped an AOD into our 73 Mach 1. The original C4 had begun to slip badly with a Wide Open Throttle 1-2 upshift. It made little sense to build the C4 up enough to better handle the street/strip 351W (not C) that replaced the original 302 2v (prior owner did that swap). The prior owner had also replaced the original 2.79:1 rear axle gears with a 3.5:1 RTractionLok set of gears. Although the engine RPM at 60 MPH in 3rd gear was tolerable, I decided to swap the C4 with an AOD from Monster Transmission. I did opt to get the firmer upshift feature, but nothing was done to beef it up beyond that. It turns out there are two different tailshafts for those AODs, and by luck ours was a short tailshaft design. In our case the C-4 and AOD lengths were only 1/4" different, where the AOD was slightly longer than the C4. In looking at the wear on the outside of the output shaft yoke it looked like I had more than 1/4" of added travel available for the rear oil seal. So, no need to alter the driveshaft. It has been working out perfectly. In my case I had not been aware of the short tailshaft situation, otherwise I would have specified it in an attempt to not needing to alter the driveshaft length. YMMV.

An aside, we are very pleased with how our AOD swap worked out. The Throttle Valve Pressure adjustment is a PITA with an oil pressure gauge having to be put into the oil pressure test port. But, that is the worst of it. The factory specs are to be at 30 - 35 PSI in Neutral for the Throttle Valve base setting, using a 0.275" spacer block while making the adjustment. I wanted my upshift points to be higher than what a 30-35 PSI setting provide, so I ended up setting my TV pressure at 40 PSI. I show how I did that in a few YouTube videos, in case that is of interest. The links are provided below. In fact, I video recorded the entire upgrade process, plus added a few TV setting videos. One video involves how I spliced the AOD Neutral Safety/Backup Light switch into the C4 NSS/BUL wiring harness. Attached is a list of our vendors and parts. Below are my YouTube links:












The following link is for the Neutral Safety/Backup Light Switch splicing:















https://youtu.be/vdR-z3KV0UE



https://youtu.be/YCBBgd-olQ0



https://youtu.be/NcYr68atRjM



https://youtu.be/iFNXTGXNNcQ



https://youtu.be/2tTwnbcZZkY



https://youtu.be/8QncIKQTvNo



https://youtu.be/b4lnPReGWuM



https://youtu.be/zfYe--Gsjdk







Setting up Throttle Valve Pressure from the carburetor cabling, and how the original auto tranny floor shifter behaves with the AOD when shifting manually:



https://youtu.be/KYIAqqYUKNo



More below

This video shows there is a difference between TV pressures in Neutral vs Park:



https://youtu.be/6hZJEnGCPvY

 

[JimB73]

We popped an AOD into our 73 Mach 1. The original C4 had begun to slip badly with a Wide Open Throttle 1-2 upshift. It made little sense to build the C4 up enough to better handle the street/strip 351W (not C) that replaced the original 302 2v (prior owner did that swap). The prior owner had also replaced the original 2.79:1 rear axle gears with a 3.5:1 RTractionLok set of gears. Although the engine RPM at 60 MPH in 3rd gear was tolerable, I decided to swap the C4 with an AOD from Monster Transmission. I did opt to get the firmer upshift feature, but nothing was done to beef it up beyond that. It turns out there are two different tailshafts for those AODs, and by luck ours was a short tailshaft design. In our case the C-4 and AOD lengths were only 1/4" different, where the AOD was slightly longer than the C4. In looking at the wear on the outside of the output shaft yoke it looked like I had more than 1/4" of added travel available for the rear oil seal. So, no need to alter the driveshaft. It has been working out perfectly. In my case I had not been aware of the short tailshaft situation, otherwise I would have specified it in an attempt to not needing to alter the driveshaft length. YMMV.

An aside, we are very pleased with how our AOD swap worked out. The Throttle Valve Pressure adjustment is a PITA with an oil pressure gauge having to be put into the oil pressure test port. But, that is the worst of it. The factory specs are to be at 30 - 35 PSI in Neutral for the Throttle Valve base setting, using a 0.275" spacer block while making the adjustment. I wanted my upshift points to be higher than what a 30-35 PSI setting provide, so I ended up setting my TV pressure at 40 PSI. I show how I did that in a few YouTube videos, in case that is of interest. The links are provided below. In fact, I video recorded the entire upgrade process, plus added a few TV setting videos. One video involves how I spliced the AOD Neutral Safety/Backup Light switch into the C4 NSS/BUL wiring harness. Attached is a list of our vendors and parts. Below are my YouTube links:












The following link is for the Neutral Safety/Backup Light Switch splicing:















https://youtu.be/vdR-z3KV0UE



https://youtu.be/YCBBgd-olQ0



https://youtu.be/NcYr68atRjM



https://youtu.be/iFNXTGXNNcQ



https://youtu.be/2tTwnbcZZkY



https://youtu.be/8QncIKQTvNo



https://youtu.be/b4lnPReGWuM



https://youtu.be/zfYe--Gsjdk







Setting up Throttle Valve Pressure from the carburetor cabling, and how the original auto tranny floor shifter behaves with the AOD when shifting manually:



https://youtu.be/KYIAqqYUKNo



More below

This video shows there is a difference between TV pressures in Neutral vs Park:



https://youtu.be/6hZJEnGCPvY

mrgmhale,​

Lots of good info!, Thanks for the links

 

[mrgmhale]

mrgmhale,​

Lots of good info!, Thanks for the links

I am not an expert in all things AOD swap, but I do have some tracks over my back from our experience, and auto repair info in general, and will gladly help where I can. Feel free to reach out for more info as needed.