Yo!! Well, I'm almost to the point of registering my project and getting the beast on the roads. I'm wanting to empty out my transmission of old fluid and replacing it with new fluid. I also want to replace the filter and gasket. Now, this is my question: I'm hearing that I shouldn't because it will do internal damage to the transmission. On the other side though, I hear that it would be beneficial to do it. What's ya'll thoughts on this and what's your experiences?
I would definitely change fluid/filter and more importantly add a transmission cooler before doing any summer cruising in TX. I have heard the urban legend that changing fluids "causes" problems. I think that some people only think of changing their tranny fluid when problems are becoming apparent. C-6 is a pretty bulletproof transmission. But behind a 460 in an RV here's what heat will do: PO had new tranny installed but not a cooler. That's smoked forward clutch remains
I failed to state that the transmission fluid is old....no telling how old though. The car when I bought it, was a one owner car and had been sitting for 7 years. When I bought it, it wasn't running at all..now it is. So, just want to make sure all components were clean and working properly.
It is an old fable that changing the fluid on an old transmission will damage it. The C6 uses a screen, you can clean it instead of replacing it. Also, your converter has a drain plug.
Anyone else have anything to add....sounds like this is a myth, just want to make sure before I proceed either way. Thanks!!
Dump all of it,you will be smart doing it. Just another old myth from people that will believe any thing. JIM
The only thing I can add is you need to know what trans you really have. Theres no such thing as a C6 Cruise O Matic. You either have a C6 or a Cruise O Matic.
if it's the car in your avatar, and it's the original trans, then it's a Cruise O Matic. The C6 was first used in 66 model cars (hence the name, C6 is fordspeak for 1966)
There is often a problem when you have an older transmission "flushed". Just dumping the fluid and replacing the filter will not cause a problem...
I did this in my '84 Bronco a long, long time ago. C-6 trans. Changed the fluid, and filter, it had been shifting fine...it had no forward gears afterward. ?????? I had been told by someone back then that the new, detergent-laden fluid might have eaten away the varnish, and caused seal failure. Is there REALLY no precedent for this, ever, under ANY circumstances? I'm curious.... It happened to me, although I'd still change the fluid and filter, and have done so plenty of times since and have yet to experience a problem again. Still.....it DID happen to me once.
This event had to be purely coincidental, new fluid cannot damage a seal. To marginally extend the life of a tired trans with hard seals, I've added a quart of Trans X, then changed ALL the fluid after running it for 200 miles. If you leave that stuff in too long, it will dissolve the seals.
I heard that old tale about not changing the trans fluid, that was made up by the used car salesman. If you let out the old fluid the oatmeal comes out too, then she don't shift no more.
Thanks everyone for your replies...I'm going ahead and changing out the fluid this weekend or when I have time. I noticed a leak from the back end of the transmission...close to where it connects to the drive shaft...I don't think it's a big deal though.
Actually, that's not correct, the C4, C6 and FMX (which was a modernized version of the early trans) were all referred to as "SelectShift Cruise-O-Matic"- and according to the '69 "Car & Driver" ad in front of me, the C6 was a $222.08 option over the stock 3-spd manual on a '69 390 or 428CJ Mach1, $37.06 on a Fairlane Cobra (which came stock with the 4-spd, not the 3-spd), and again $222.08 on the big-block Torino GT, as it came stock with a 3spd like the Mach1. Somewhere I also have a full-page '66 Mustang ad saying something like "Why doesn't Mustang bolt Cruise-O-Matic behind the 271hp solid-lifter V-8". I also have the '66 Ford sales brochure with all the options listed, as well as the mid-'64 brochure introducing the new Mustang with the rest of the line included, that I got at the dealership my mom did the books for back then. The early trans has become the "Cruiso" in slang terms, but they all actually were called Cruise-O-Matic by FoMoCo. The '66 C6's even retained the oddball "green dot" PR2D1shift pattern of the early trans, with the valve body being changed to the "normal" PRND21 in '67 Some '66's with 390's still had the early trans, but my '66 428 T-Bird has a C6 with the green dot pattern, as did the '66 428 Country Squire I just sold
Ford-O-Matic is a Borg Warner transmission. Cruise-O-Matic is a Ford unit but is based on BW trans. BW also made Studebaker's Flight-O-Matic.
Yes, the ford-o-matic was a BW trans..........and the Ford built FMX cruise-o-matic was a derivative of that......but C-4 and C6 cruise-o-matics are not BW design derivatives. And...MeanGene427.......I don't understand the ad saying "why Ford doesn't bolt the cruise-o-matic behind the 271hp engine" in the '66 Mustang brochure. I worked in a Ford Dealership in that period and I know for a fact, having seen and driven a '66 Mustang GT Fastback, that they came so equipped. It was the C4 cruise-o-matic though, not an FMX or C6. Ray
Yeah Ray, that was the point of the ad, they were pointing out that it WAS available- the ad read something like "you can stop asking why-" as it wasn't available in '65. It wasn't in a brochure, it was a full-page magazine ad- had a picture of a '66 scooting across an intersection. You would have loved the little Mustang the the dealership owner was driving around back then, HiPo GT convertible, 4spd, pony interior, Rally Pack, and "knock-off" hubcaps, two-tone blue with white interior & top. I saw it a few years later, and the salt had got it, rear quarters were gone about 1/3 of the way up the tires My folks bought a new turquoise '65 'Bird while mom worked there, I watched them unload it off the transporter, and I had the 'Bird model/Philco radio that came with it for many years, it "disappeared" out of my bedroom at my grammas house while I was away- I think my cousin got it, I know he stole and sold my Huffy "Rail" bicycle.
Just out of curiosity (and for the fact that I've never messed with a transmission), how much do you think that it would cost to rebuild a cruise-o-matic transmission? I would try to do it myself but dont have the tools or the know how.
you might have a hard time finding a shop to rebuild a cruise-o-matic. most shops around here wont warranty them because the cast iron center housing is prone to cracking
Drain the transmission and torque convertor (Convertor has a 1/4 plug) in it and is a easy job. Change the fluid and filter. You said it has a small leak at the rear--Thats the rear seal and again easy fix by removing the drive shaft and popping the seal out with a big screw driver. My as well do it all while you got the pan off the transmission. Next thing is check the ujoints while you have the drive shaft out and grease-or replace them now.
Make sure to drain the convertor too, if it has s drain plug in it. Also use type F transmission fluid, it has more grippers in it and is ford spec.
If you change the oil in a trans that's already toast it will probably start slipping. That is the basis of the caution you were given.
Hey Ray....thanks for the advice man. I finally got this beast registered today and with antique plates. Question: should I drive it still knowing that the transmission is leaking from the rear seal? I found a rear seal at NAPA. I have the rest of the parts to do the job that you're suggesting I do (gasket and filter).
That depends on how bad the leak is . If you have a small spot on the floor but if its puddeling no fix it.
Lots of Ford autos leak from the rear seal when parked, especially when the front end is uphill. I think the parking pawl deflects the tailshaft. Does it sling fluid on the body or just drip on the ground? Don't they have a bushing in the tailshaft housing that the driveshaft yoke slides into that should be replaced when the seal is?
Squirrel is right on. what you got dere is an FMX if it came out of that 64 in your avitar, if it has a removable bell with a cast iron case , dats what you got...
I've had ransmission guys tell me that if the fluid hasn't been changed regularly that it stirs up stuff and clogs the valve body. I have also heard from other tranny guys that that is a bunch of carp (as in fishy). I personally have never been able to tell if the fluid has been changed regularly or not so I just change it. I guess I have never had one that the fluid has never been changed because i have not had a problem with one after changing fluid. What you don't want to do is wait until your tranny is toast to change the fluid.
That's why there's usually no drain plug on a trans pan, so you have to drop the pan to change the fluid, and then you'll do the filter, and clean the carp (out of the pan). So if you do the filter and pan, and also drain the converter, there's not much stuff left to stir up, eh?
No, don't change the transmission fluid, the trans will burn out. And don't change the engine oil either, just top it off. And keep using the old filter. Otherwise the engine will blow up. And never refresh the radiator coolant, or the radiator will leak. But you SHOULD add water to the battery if the cells get low. And put in a new headlight if the old one burns out. Remember these rules. WTF?
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