C-4

[GilroyRacing]

I went and picked up a C4 last week.

I am going to "try" and put it in this week, I dont think it is going to happen though.

I need it to remain colom shift, so I need to check the linkages and see what I have to do to make it work.

[Mercmarquis]

is it a stock c4?

[GilroyRacing]

It was rebuilt, and has a shift kit.

[DuceAnAHalf]

it would also be a good ide to replace the stamped servo cover with a aluminum one

[GilroyRacing]

How many qts. of trans fluid does it hold?

[DuceAnAHalf]

http://www.tciauto.com/Products/TechInfo/fluid_capacity.asp

5.5 +what the converter holds

[GilroyRacing]

Thanks

[SLYDAWG]

AOD to C-4

I went and picked up a C4 last week.

I am going to "try" and put it in this week, I dont think it is going to happen though.

I need it to remain colom shift, so I need to check the linkages and see what I have to do to make it work.

Swapping to a C-4 is a bolt in 'IF' you have a large bell (164 tooth flexplate), then your old AOD flexplate can be reused. If you have a small bell (157 tooth), then a new flexplate will have to be purchased.
Driveshaft is the same length and bolts right up.
Column shifter can be retained by rotating the linkage mount 180* at the trans. IIRC, for the AOD it points down. For the C-4 it must point up.
The trans crossmember in the earlier cars is simply moved forward. Not sure about the 90/91 cars. May have to drill some new holes.
Trans mounts are the same.

With the trans out of the car, it would be an excellent time to replace the rear main seal in the engine and put in a new trans moount, as the old one is probably fubared from age.

Should be ~2hr swap.

[DuceAnAHalf]

oh, somethng i ran into on my swap. the C4 big bell uses shorter bolts than the AOD bell. i could not find any 7/16-14 bolts on a saturday in the right legnth so i had to stack a bunch of washers on a couple bolts.

and 90 and older have the second set of holes for the C4

[GilroyRacing]

The car that it is going into is an 88 vic. The c4 I picked up has a small bell housing, but i have the flexplate that goes along with it.


I just thought of another thing, what about the starter? Will I be able to use the same starter I used with the AOD?

[SLYDAWG]

AOD to C-4 again

"oh, somethng i ran into on my swap. the C4 big bell uses shorter bolts than the AOD bell. i could not find any 7/16-14 bolts on a saturday in the right legnth so i had to stack a bunch of washers on a couple bolts."

Ahhhh......forgot about that. I added a couple of washers behind every bolt.

"I just thought of another thing, what about the starter? Will I be able to use the same starter I used with the AOD?"

Yes.

The only thing that will not interchange is the small bell C-4 onto the AOD flexplate, as the AOD uses the 164 tooth flexplate.
The trans crossmember must be moved forward and bolted into the front holes.
Everything else interchanges.

[1987cp]

Just one item I've noticed, there were apparently at least two different shift levers for the C4. When I bought the one I have now to swap into my '79 (an original C4 car), I asked a buddy why the shift linkage wouldn't work, and he said to flip the lever 180 degrees. After I got the lever out I realized my original one was quite different (wanna say shorter), so I put that one in instead. Now that the '79 is gone I'm hoping to use the C4 with the stock AOD shift linkage in the '81. So far the only major issue I'm noticing (aside from trying to find stuff in my messy garage) is that the way the linkage mounts to the bellhousing is different - but that'll be easy to fix if it turns out to be completely incompatible, as it's just steel. It will be rather interesting to see which of the shift levers I end up using.

[GilroyRacing]

Its sounds like a pretty straight forward swap, I am going to try and get it done this week. It all depends on how busy I am at work, and if I can get down the road early one day, and If i can get the car on the lift.



We will see.


Thanks for all of the great info guys I really appreciate it!!!

[fordktpjoe]

I have access to a small pattern C6....are the C4 and the C6 close to the same as far as linkage? I don't have it in front of me, so I can't check it out.

[1987cp]

Not sure about that, but I can take pics if no one has any handy. The C6 does weigh as much as an AOD (maybe more) and isn't supposed to be particularly mechanically efficient, so I'd probably only run one if I needed the bigger torque capacity.