C6 Transmission...my experince

[Grand1]

Sure this topic has been discussed before; but thought my experience might help someone
(there seems to be interest in old barges with BBF 460....)

1. Will be using "TYPE F" tranny fluid .

2. Changing the Vacuum Modulator.

3. Pan and Filter

4. Tranny Cooler.


-First, Drain the C6-


Here are some images.
Note there is one longer bolt that holds the filter! When I dropped the pan; no metal shavings....only some in the filter.

---One must drain the torque converter----Remove shield, Then its time to play a game!
Find torque converter drain plug by tapping ignition switch before turn over!!!!
I scored center mass on the drain plug; after spinning the wheel...torque converter drained

[Lincolnmania]

i thought c6's took dextron?

[sly]

I don't really think C6's care. You could put industrial hydraulic fluid in there and it would probably run.

[87Topaz]

Would not Type F produce harder shifts? I think it is what was originally called for but you could use Dextron or Synthetic fluids for softer shifts. Not a "trany jock" so perhaps someone can jump in here to verify.

[sly]

from my reading... either will work. Specs were: C6 as original: 1966/76 = Type F // 1977/96 = MERCON

Seems type F will give firmer shifts since the Mercon has more friction modifiers to soften the shifts.

[DerekTheGreat]

coughcoughDEXRONcoughcough

[Grand1]

No coughing .....type F is time tested....to include transmission rebuilders that swear Mercon wears down trannys with the SOFT shift; type f is in the tranny

[His Royal Ghostliness]

I don't really think C6's care. You could put industrial hydraulic fluid in there and it would probably run.

Yup, fluid for heavy equipment with wet clutches and stuff... Type F ain't got nothing on that, especially the synthetic stuff. Expensive sucker tho, but ah well, gotta pay to play.

IMHO the problem with the C6 is not what fluid it runs, but how much of a bitch it is to dial the shift points properly (both when you want her to shift and how you want her to shift). Manual valve bodies are God's gift to C6 users, especially the reverse patterned type.

[GM_Guy]

If you are reusing anything, especially clutches use the fluid that has already saturated the clutch material. An old transmission guy told me that years ago when I was asking about trying trick shift, or using type F in the hydramatic and other such cheap-ass shift feel nonsense. If you are putting in new clutches and essentially tearing the thing down he said use whatever the hell you want, but once you select a fluid stay with it or your clutch material will not last as long and tend to break down after a change in fluid type.

Alex.

[Grand1]

All sound info.....I would have been very hesitant to change the fluid if there was miles on my ride......but 63,000 miles was a no brainer

This was confirmed with the lack of metal shavings and the state of the tranny fluid. Replacing the vacuum modulator will help dial in the firm shifts......least I could do with all of the top end work

[gadget73]

Something else to consider is whether the clutch materials or the pump changed along with the fluid change. Would really suck to find out that something is in fact different and you fry the trans from using the wrong goat blood.