1964 Thunderbird Transmission Fluid

[ricksta56]

Hi John,
Yes, with Ebay, maybe I don't always read the fine print. But thanks for pointing out they and other companies list parts incorrectly sometimes. I ran into something from O'Rielly listed off too. a whole different Nissan job.
John is the C6 a very good transmission, I imagine it is supposed to be an improvement on the cruise-o-matic, but what are the differences? When I drive my car, it feels like it's all set up, geared for top end speed. As if there is a long low first gear like it would never be quick off the line or spin the tires. There are probably some other adjustments that can be made. I seem to remember from my youth when I had a slew of F100's there trannys had an adjustment with a lock nut than maybe a half turn of the stud than retighten the lock nut. Similar to a cam chain adjustment, or I've heard about adjustable belts in association with trannys.

[simplyconnected]

C6 transmissions are stump pullers, meant for Ford trucks. They are slightly more parasitic than the C-O-M and they are still confined to three speeds BUT... If you want 15% lower first gear, replace your sun gear with one from an E4OD transmission. You'll enjoy better starts from the light without changing your rear end gears. Second gear is slightly lower too but 3rd is the same 1:1.

I have lots of respect for the C-O-M. It's a good strong trans unless you're going to pull trailers and haul. But, why would you do that with a Squarebird?

Be careful choosing a C6. The trans housing is part of the bell housing casting. Ford made FOUR styles of C6. A SBF C6 will not fit an FE C6. If you can, get one still bolted to a 390. - Dave

[ricksta56]

...I'm not attempting a trans swap. I'm basically planning a service this spring. When you say the C6 is more parasitic than the C-O-M, do you mean dependent on motor rpm.

I understand you don't want a trans swap. I suggested you replace your C6's sun gear with one from an E4OD. That's not a transmission swap (any more than changing your rear end gears are not an axle swap, for example.)

Automatic transmissions need to USE some of the engine's power to perform transmission functions, like running their pump, etc. The C-O-M uses less (parasitic) power than the C6. So, under normal driving and everything being the same, the C-O-M puts more engine power to the rear wheels. The C6 is designed to stay together under heavy hauling and BIG HP engines. - Dave

OOPS, I didn't mean to edit YOUR post, Rick.

[ricksta56]

Hi Dave,
Thanks for being in, Let me ask you directly. Do you recommend a fluid change along with the screen/filter gasket kit etc.
Keeping in mind the car has sat some 35 odd years. I was also trying to figure out if there is also a mechanical adjustment for my C6.

[simplyconnected]

YES. The color and smell of your trans fluid tells a story as well. If your trans fluid is no longer red, change it. If it smells burnt, change it and suspect your trans was run with LOW fluid level. Nothing will kill a trans faster than low level because the fluid needs to cover bands and drums, clutch plates, etc. The fluid carries heat away,

Transmission fluid does contain condensation. This, along with temperature, affects the way it shifts and works. You can imagine, cold oil with moisture, working with fiber clutch plates and band material.

Engine heat normally evaporates any moisture after running for awhile. So, a daily driver is rarely affected.

Your trans fluid, rear end gear lube and your brake fluid ALL need to be changed at proper intervals, not just motor oil.

If you ever watch a transmission overhaul, the first thing done is to tear it down and WASH the housing and all the components. They wash using high pressure HOT water with detergent. All the nooks and crannies harbor pieces of junk (band and fiber material) because the filter doesn't get it all. They also wash all the components using mineral spirits in a tub with a brush. Only then, can they see wear and tear in sleeves and bearings, etc.

Mechanical adjustments are covered in your Shop Manual, if needed. - Dave

[ricksta56]

Great thanks Dave , The trans service is on schedule.