AOD to C4

[dbdragracing]

My AOD is just about due for replacing. After looking around a bunch at performance automatics I have noticed that the C4 trannys are capable of holding a lot more power and are backed by a better warranty. I realize switching willl cause me to lose overdrive, but the car doesn't see much highway use anyways. Now my question:

What does it take to switch from an AOD to a C4? computer? mounts? converter?

Any info will be a big help. Thanks.

 

[85_SS_302_Coupe]

I've never made this swap so i can't help much there, but i can tell you that you'll REALLY miss that overdrive, more than you think you will, hiway driving or not. I ran a C4 for a few months when i first got my coupe, and it SUCKED for speeds anywhere over 60mph. It took off like a raped ape, but had NO cruse-ability. Of course, i've got 4.10 gears, but i'm sure you have plans for more than stock gears someday anyways.

 

[dbdragracing]

Yeah I'm going to be swapping to 3.73s soon when I do my traction-lock rebuild. I've been reading about ways to beef the AOD up so I can keep OD. I just don't want to waste money on a weak tranny and have to do this all over again. Keep the comments coming. Thanks.

 

[2002BLGT]

for a street car a C4 and 355s are a good match

 

[The Shape]

I will agree the OD is nice to have. But people did drive around for years with C4 trannys before the AOD came about so it can be done. Your gas budget may increase a bit though. As for as the swap I can say for sure you don't need to do anything for the computer since the AOD doesn't use it. I am fairly sure your AOD mount will work and since the Ford Racing aluminum D/S says it fits AOD and C4 trannys then I would assume your stocker would to. I have never done the swap so I amnot 100% sure on that.

 

[carbed87]

.

if yu want to think about swapping to a c4...talk to 86410c4 hes a friend of mine, and is doing it himself...all i know is that the driveshaft legnth is perfect, and the stock mounts can most likely be re used... pm him, he'll tell you all about it

 

[Qwk87Coupe]

You will need a C4 flexplate & converter, the factory driveshaft, tranny crossmember & starter will all work, I believe B&M sells a kit to convert the factory shifter to work with a C4, if not you'll need a shifter, I dont believe the computer will make much of a difference I've swapped from 5sp to C4 and AOD to C4 using stock computers and havent had a problem

 

[ECU5.0]

You will need a C4 flexplate & converter, the factory driveshaft, tranny crossmember & starter will all work, I believe B&M sells a kit to convert the factory shifter to work with a C4, if not you'll need a shifter, I dont believe the computer will make much of a difference I've swapped from 5sp to C4 and AOD to C4 using stock computers and havent had a problem

not trying to steal the thread, i just have a question. what all did you need to swap from a 5 spd to a c4?

 

[MrKwik]

You will need to make sure to get the "small" bellhousing for a 157t flexplate. They arent real easy to find but they are around. The large one will fit with short tubes but its tight and the flexplate and converter are alot more expensive. I have heard rumors that the AOD flexplate can be used with the large bell C4 but I'm going to call bull**** on that one unless someone proves me wrong. I just dont think its shaped correctly to fit the C4 converter. Anyway, just get the small one and be done with it. I used a TCI flexplate #890-529610 (157t, 50oz imbalance, 10.5" bolt circle) from Jegs and it was only like $60. You will also want to make sure to get a stall with a 10.5" bolt circle, not 11.5". Your stock driveshaft and crossmember will work but you will need to cut the spot welds on the crossmember and move it all the way forward if I remember right, could be all the way back but either way its adjustable after you cut the welds. I custom made a bracket to hook up the stock shifter but you can use an aftermarket or hunt down the B&M kit. I wasnt able to find it myself. I also havnt been able to track down a corrct speedo gear so your on your own there. You will also brobably have to bend up some new cooler lines, that alot of fun. I will caution you that if you have anything other than stock gears you will miss OD more than you think. I have 373's and I cant stand to drive the car on the highway more than a few minutes at a shot. Car is now for sale for this very reason. So make sure you can live with it before you do the swap.

 

[crazypete]

Go here and input your tire size and look under the category "auto" (thats the C4)

http://www.4x4cyberstore.com/website/rpmchart.html

Homes, you'll be pulling THREE GRAND just trying to go 60 mph with 26.6 tires and 3.73's. You will HATE it in the long run.

I thought I was rpm friendly and I went 4.56's and AOD. I started to dislike the over-revvy feel of the car. Then I started to really dislike it.

It felt almost too tourqey/spun up. Yeah the motor can take it but it didnt feel right. You were always up in the powerband so the car would lurch forward when you put the pedal in and lurch back when you backed off slightly.

Do this. Install those 3.73's first then leave the AOD'ed car in D not OD and drive around for a few weeks. Thats basically your C4 right there. 1,2, and a 1:1 3rd gear. You'll get sick of it real real fast.

If you wanna build up an AOD, it's not nearly as bad as you think. You can get around the weakness of the AOD quite easy. A hardened lockup shaft $150, kevlar band $25, a+ servo to hold the band $125, Good shift kit like transgo $100, Rebuild kit $75, 3K stall $300, cooler $50. About 500 without the converter including the rebuild. If you wanna rebuild it yourself, I can get you exploded diagrams and pictures and whatnot. The hardest part is basically getting the 200 pound AOD out. Then it's unstacking stuff held together by 4-5 large screwdriver friendly snaprings. Makes an ATFey mess but is pretty easy to do.

Good luck

 

[Qwk87Coupe]

Summit sells the small bellhousing for around $60-70, its not listed in the catalog, if you need one just call I've ordered them before.

 

[MrKwik]

Summit sells the small bellhousing for around $60-70, its not listed in the catalog, if you need one just call I've ordered them before.

Wish I had known that. I spent more than that on an old used one and it took me quite a while to find it.

 

[SAY GO]

My AOD is just about due for replacing. After looking around a bunch at performance automatics I have noticed that the C4 trannys are capable of holding a lot more power and are backed by a better warranty. I realize switching willl cause me to lose overdrive, but the car doesn't see much highway use anyways. Now my question:

What does it take to switch from an AOD to a C4? computer? mounts? converter?

Any info will be a big help. Thanks.

youll never regret going to a C4! the crossmember mounts have to be busted out so they can move back and forth freely, mine were to badly rusted so we actually recut and welded a new location for, your computer is fine, will need a new converter, while your there you should buy a SFI flexplate, just to be safe...

 

[crazypete]

Just do the 3rd gear/leave it in "D" test before you jump into the conversion. It wont seem too bad with your highway gears but after a gearswap, you'll be hurting

3K rpms at 60 mph with 373s...remember that.

 

[bionic_chronik]

I did this swap in my 91 GT, went from an AOD to a C4. It was kind of a pita for us, because we jumped into it not knowing what we all needed. I picked up a flexplate from a local mustang shop for like $130. I also had to buy a bigger starter for an older C4 tranny at autozone(cousin said the stocker wouldn't work). With the crossmember, we rigged up an extended steel mount and bolted the crossmember up to it's stock location. For the tranny lines, we cut the stock AOD tranny lines and attached high pressure rubber hose from the end of the stock line to the tranny(make sure you get the rubber hose atleast 2" onto the stock AOD line and DOUBLE CLAMP it! mine is still leaking from the lines because I'm too lazy to get under there and double clamp it lol. Been driving the car for almost 4 months now without any problems other than it leaking fluid from the lines. I need to get the shifter right still though. When we first did the swap my cousin welded the linkage up to the shifter so it was all wacked out, park was reverse and so on. He did that just I wouldn't have to crawl under the car each time I wanted to put it in a gear... well that and so I would have first haha. But yeah the weld broke, so I got a stock 3spd shifter out of a 95 V6 mustang and got that in the console... I just need to bolt it down and hook the linkage up. If that shifter doesn't work, I'm going to order a B&M conversion kit. If this tranny ever blows up on me, I won't hesitate to put a 5spd setup in it next... I believe the car would feel 30x quicker with a stick.

 

[Qwk87Coupe]

not trying to steal the thread, i just have a question. what all did you need to swap from a 5 spd to a c4?

C4, 157T flexplate, converter, small bellhousing, shifter, thin spacer that goes between bellhousing and block, transmission lines & cooler

 

[ECU5.0]

C4, 157T flexplate, converter, small bellhousing, shifter, thin spacer that goes between bellhousing and block, transmission lines & cooler

awesome...now i just need to find someone who will buy my tko 500 so i have the money to get the c4 and whatnot

 

[ECU5.0]

what about a tv cable or anything like that? if i get one it will be a manual valve body. i just want to get a list of all the parts that i will need to do this so i can get an estimate so i know how much to ask for my tko. thanks

 

[Qwk87Coupe]

I did this swap in my 91 GT, went from an AOD to a C4. It was kind of a pita for us, because we jumped into it not knowing what we all needed. I picked up a flexplate from a local mustang shop for like $130. I also had to buy a bigger starter for an older C4 tranny at autozone(cousin said the stocker wouldn't work). With the crossmember, we rigged up an extended steel mount and bolted the crossmember up to it's stock location.

You sure it was a C4, did you actually try the orig. starter or were you just going on the fact your cousin said it wouldnt work, also never had to modify a crossmember?

 

[Qwk87Coupe]

what about a tv cable or anything like that? if i get one it will be a manual valve body. i just want to get a list of all the parts that i will need to do this so i can get an estimate so i know how much to ask for my tko. thanks

With a manual valve body you wont have to worry about it just remember to downshift, I have a dynamic C4 with trans brake, manual VB, and all the other parts to do a swap minus the converter PM me if you'd be interested in a swap or need any help once you get into it