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1965 Ford Galaxie LTD, 1966 Fairlane, 1967 Cougar
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Discussion Starter · #1 ·
While my 65 LTD 390 runs and drives decent, the engine has enough blow-by and exhaust header leaks that I need to go through a usual rebuild. Being a 65, it has the MX column shift transmission (C5MP-7006-A case, tag PCE-BK matches this setup).
I have two other FE pattern C6 transmission (1967 and 1976) and I've been searching through forums on swap info for weeks with VERY conflicting opinions. Some think the MX is fine, others call it trash. I'm still left up in the air as to go through the trouble of a C6 swap which involves some non standard mount bracket, shifter, driveshaft modifications or to just rebuild the MX.
One big thing is that I want to add a Gear Vendors OD in the future but I can't confirm if their units will mate to the the MX.

The simple path is to keep the MX as everything will just happily bolt back up, but maybe there's a good reason to swap in the C6 that I'm missing here?
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The MX is running okay?
 

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Hello Galactic,

You raise some really good questions about which transmission to settle on. The answer really depends on what you want and what you expect out of the car. Just to give perspective any transmission has pro's and con's. The MX is perfectly fine for stock applications. The pros are keeping it requires no other changes to the car or buying other parts to mate another transmission to the car. Also the MX and FX (light duty version of the MX) has a front and rear pump that allows the car to be pull started should the starter fail or the car can be flat towed without damage to the transmission as the rear pump (driven from the propshaft) keep line pressure and lube pressure up.

Now the cons, there's no really no aftermarket support for high performance parts for an MX and even getting parts for a stock rebuild is problematic. A few years ago I rebuilt an FMX (similar) and trying to find stock parts were a pain. I had to rob parts off an old FX and machine on a mill I had at the time to complete the rebuild.

Now the pros and cons of installing a C6. The pros are plenty of aftermarket parts for performance or just a stock rebuild are available, with the exception of the torque converters. FE's have a unique crankshaft pilot diameter and require a torque converter only for them. The last two C6's I built required core charges for the replacement torque converters which adds to the price of a rebuild as shipping boat anchors is pretty expensive.

The cons of the C6; The C6 is an energy vampire in stock trim, it consumes quite a bit of energy (fuel mileage/engine power) just to operate normally. You can mitigate this by fully rollerizing the internals and using high quality friction materials and steels with special coatings. But all this comes at a cost.

The other cons are the modifications to the car to accommodate the C6. You'll need a different length propshaft and '66 -'68 transmission cross member and a C6 mount. The bad news about the C6 mount for 1966-1968 is that it's discontinued and not the same for the FX and MX. You can still find NOS mounts but the prices have skyrocketed.

Here's another possibility to consider since you expressed interest in overdrive. There is an aftermarket bell housing that will bolt an AOD, AODE or 4R70W transmission (have to cut the case bell housing off) that allows that overdrive transmission to bolt directly to an FE. I started doing research on this as I am interested in this as well. It appears you can use the FE's original flex plate and starter but you need a pilot adapter for the torque converter. This option would give you 4th gear and lock up for much better fuel mileage and the wide ratio of the 4R70W would give your LTD more zip off the line. Obviously the cons for this are once again a different length propshaft, yoke, transmission mount arrangement and either a TV cable or rod needed (AOD) or a transmission controller for the AODE or 4R70W as they both are electronically controlled transmissions.

Just thoughts.

Cheers
 

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I'll chime in here. I went thru this dilemma on my 66 as well. Mine was a relatively low mileage car (65k ish) and i took a long hard look at the mx I have. everything looked and ran great prior. I adjusted the bands, cleaned everything and resealed the input and tail shaft. cleaned the filter (brass screen) and swapped the only failing part, the modulator. I did build my motor mildly with rpm performer heads, rpm performer intake, 750 holley, sanderson headers, and a relatively mild cam ('modern' 390gt profile from howards). I also added a transmission cooler. I have been driving the car pretty regularly for the past 3 mos and do get 'spirited' on it on occasion here and there and the trans has always held up fine and shifts nice and sharp. .02
 

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1965 Ford Galaxie LTD, 1966 Fairlane, 1967 Cougar
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Discussion Starter · #5 ·
DesertXL and M in SC, thank for the input.
This LTD is going to be kept bone stock from it's original trim, I have the Fairlane and Cougar to work on muscling up. With what you've listed and the general good condition of the MX, I think I'm going to do a rebuild of the MX to keep it simple and reliable. For me it's an around town and highway cruiser, it has tall tires and a 3.0 open rear as it is.

A trans cooler certainly wouldn't hurt, so I'll have to add that and hide it low in the engine bay perhaps. Once I crack the case open over the next week or two I'll post pictures of the condition to get some feedback. I've rebuild a C4 and a C6 without issue, although I went through an AOD rebuild and hated it. All the lip seals, endplay adjustments, and year specific parts made it a pain, even though it was the early mechanical TV version.

I still need to see if a Gear Vendors unit will hook up to the MX, that's something that I'd like to keep as an option for a year or two down the road.
 
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