FMX to C6 question

[RustyNCa]

Does anyone know, can you run the flexplate from the Cruise-a-matic to the C6 converter. IE, can I just leave in the flexplate that I have in there, or do I have to change it out?

I'm already running a 390 with a later style starter, but I don't remember if I changed the flexplate back when I swapped out the motor.

Cheers and thanks for any help.
RustyNCA

[jopizz]

If you are using the later starter then you have to have the later flexplate. They are not interchangeable. It should work fine in the C6.

John

[simplyconnected]

Does anyone know, can you run the flexplate from the Cruise-a-matic to the C6 converter. IE, can I just leave in the flexplate that I have in there, or do I have to change it out?

I'm already running a 390 with a later style starter, but I don't remember if I changed the flexplate back when I swapped out the motor...

I have to look at your question backwards to understand it. You're running a 390 w/late starter motor. Now, you want to know if a C-O-M will fit?

Flex plates and converters simply bolt together with four studs/nuts.

C6 comes with its own integral bell housing (with starter motor bolt holes in it). Depending on what size car the C6 came out of it could use either the 157 or 164 tooth flex plate. Squarebirds with a C-O-M used a flex plate with 153 teeth and 15"-diameter.

If you're not sure, do a 'mock-up'... Outside the car, mount the starter to the bell housing and mount the flex plate to the torque converter. Now slide the torque converter into the transmission's input spline and see if the starter teeth mesh. The difference is 1/2" in flex plate diameters.

You could also count the teeth on your flex plate. 153 teeth fits a C-O-M bell housing. - Dave

[jopizz]

To use the later starter your flexplate has to have 184 teeth. Thunderbirds in 1965 and 1966 used the same flexplate whether they had a COM or a C6.

John

[OUR5T8BIRD]

To use the later starter your flexplate has to have 184 teeth. Thunderbirds in 1965 and 1966 used the same flexplate whether they had a COM or a C6.

John

John, is there not a difference for '66 if it was a 428 having to do with balance weights on the flexplate ( or drilled weight balance holes ? .

[jopizz]

John, is there not a difference for '66 if it was a 428 having to do with balance weights on the flexplate ( or drilled weight balance holes ? .

Yes, the 428 does use a different flexplate than a 390.

John

[pbf777]

[QUOTE=RustyNCa]Does anyone know, can you run the flexplate from the Cruise-a-matic to the C6 converter. IE, can I just leave in the flexplate that I have in there, or do I have to change it out?


You will need to buy the correct flexplate for the C6 (1966 thru say 1970 car application & thru 1977 for light truck), as the converter offset (depth) for the earlier MX, FX and FMX family of transmissions (if this is what you are indicating you have with the description "Cruise-a-matic", as Ford applied this vocabulary to several different units over the decade) and C6's are different.

No ifs, ands, or buts!

Scott.

[RustyNCa]

I guess how I worded it was confusing, but I think I may understand your answers.

My 58 had, well still has, a 390 in it with a modern starter, but running the original transmission. That transmission and I think primarily the converter finally started giving up after all these years.

So I have pulled the trans and have a couple C6 transmissions, with converters and flywheels sitting in the corner. One C6 came with a Mercury 410 motor I have, the other is from a pickup truck.

I was just wondering if anyone knew if the flywheel I already have on the motor would work with the C6. If not, I do have the flywheels that came with each C6.

Thanks for the help.

RustyNCA

[pbf777]

You will need to use a flexplate that is appropriate for the C6, but not the units for a 410 or 428 cu. in. engines as these carry counter weight not applicable to your 390 cu. in. engine.


Scott.

[jopizz]

You will need to buy the correct flexplate for the C6 (1966 thru say 1970 car application & thru 1977 for light truck), as the converter offset (depth) for the earlier MX, FX and FMX family of transmissions (if this is what you are indicating you have with the description "Cruise-a-matic", as Ford applied this vocabulary to several different units over the decade) and C6's are different.

No ifs, ands, or buts!

Scott.

If that's the case then how come the flexplate you mention has a 1965 part number (C5AZ6375D). Ford didn't use the C6 until 1966. They were still using the COM in 1965. Just asking.

John

[pbf777]

Nope!, can't explain it, wasn't there. But, with the same logic, why a C5# if for the C.O.M., (vs. say a B8 or B9#) since the C.O.M. appeared in the late 50's? Also consider that component assemblies which appear this model year where in engineering the year before (or more).

But, you may be correct, in that I believe the C.O.M. was produced only in 1965(?), with the new starter arrangements before being replaced by the C6 (in automotive applications). So, did the C6 use the C.O.M. flexplate; or perhaps the C6 was not ready for production, as intended, so the C.O.M. got the C6 flexplate (to use the newer starter) for one more year? And what other engineering considerations may have been made to make such happen? I don't know?

But, I have been informed by several transmission suppliers and torque convertor producers, over the years, that the C6 has it's own "converter-depth" dimension not shared with other units. And perhaps, even this statement may have simply over looked the 1965 only C.O.M.? Very possible. Note that this dimension is not overly critical, so even testimony of what someone else "got-away-with" does not pass muster.

One (RustyNCA) can establish with a somewhat accurate comparison (measurements) of the unknown unit (not original for the '58) from the vehicle to the known C6 units present for compatibility also.

So since we (I ) seem to be left with doubt as to the appropriate use of an existing unit, from another application, and a minor variation could lead to catastrophic failure; and since the appropriate unit is readily available (even perhaps at hand, and maybe the existing ring gear teeth only appear so-so anyway), they're not expensive ($60.00 +/-, oriental imports $30.00+/-), this leads me to advise......swap it!

Someone (please! ) with the original Ford parts books, of the period (don't completely trust aftermarket listings) look up the C5AZ-6375-D unit; is it correct for the 1965 w/ the C.O.M. transmission (note that"Cruise-O-Matic" term was used in some literature to describe the C6 also!).

Scott.

[jopizz]

The information I got is direct from the 65-72 Ford MPC. Ford went to the 184 tooth flexplate as well as the later starter in 1965 replacing the 153 tooth flexplate and starter with bendix that was used until 1964.

John

[simplyconnected]

Does anyone know, can you run the flexplate from the Cruise-a-matic to the C6 converter. IE, can I just leave in the flexplate that I have in there, or do I have to change it out?

I'm already running a 390 with a later style starter, but I don't remember if I changed the flexplate back when I swapped out the motor.

The C6 came with many bellhousing mounts because it was used in many engine/trans combinations. The integral bellhousing is the reason why the buyer must be sure of which engine family HIS C6 fits.

Do you happen to know what year engine your C6 came out of?
Do you know what model it was in?.. a truck (or Lincoln or Mercury)? C6 was also popular with SBF 351W engines as well. - Dave

[pbf777]

John, thank you for supplying the application listing.

But, being the doubting thomas that I am (I have been lead to water............, more than once ) and I believe, I mentioned in a previous post concerning inaccuracies that will be experienced in some literature (not implying that that with which you provided is such), and being a transitional period for the transmission units, with the compounding issue of Ford using the same terminology ("Cruise-A-Matic") for both, I wish I were left with no doubt, but...... ?

Getting back to the original question, the title inquires: FMX to C6? No! The flexplate from the FMX does not interchange with the unit for the C6, if only for the reason of offset.


The Ford C6 main housing was available with bellhousing configurations to fit: FE, MEL, 385 (also 6.9/7.3? D's), and 335 (later adopted for SBF in light truck) series engines for automotive (car) applications (did I miss one?). To the best of my experience/knowledge, year makes no difference for proper fitment, within the appropriate engine series of course.

There were however many different chassis applications (within each engine series) which incurred a multitude of other component differences, for example: flexplates, torque converters, oil pans, tail shafts & housings, flanges & yolks, internal components such as: clutches, plates, drums, bands, levers, servos, planetaries and valve body modifications, etc.,etc.

Scott.

[jopizz]

I've checked multiple parts books and they all show the same part number for the 390 and 360 engines from 65-71 in cars and up to 1976 in trucks. From my personal experience the flexplate from a 1965 Thunderbird COM fits a 1966 Thunderbird C6. I can only go by what I know, not what someone else has said. Seeing is believing in my case.

John