Ford C6 won't go into third, shift linkage problem?
John Bauer III
Group:
Doing a little road testing on my van over the weekend and after getting
the right axles, gears and tires all installed, I believe it never makes
it to third gear. Here is what I know: 77 C6 with transfer case in 2WD
high, 30" tires, 3.54 ratio, 460 engine. With the pedal depressed as if
my grandmother was in the passenger seat (taking it really easy on the
acceleration), I noticed the first to second gear shift occurring about
15mph (sorry, no tach yet), assume I should make it into third about
30-35mph??? but it never happens. Made it to about 45-50mph which major
engine whine and no shift into third. Placed the transmission shift
lever from drive into 2 and noticed the same lack-o-shift into third.
Tried moving between D and 2 at various speeds and noticed no change in
shift of any kind. After driving a few miles and with the engine at
good normal operating temperature, smelled the trans. fluid on the dip
stick and it looked reddish (not black or brown) and smelled the fluid
(no burned smell noticed). Fluid level appeared to be in the normal
fill range with the engine running, trans in park and pretty much level
ground.
This is my first serious experience with diagnosing auto trans problems,
always been a manual guy.
I have noticed that where the shift linkage comes from the column to the
trans, there appears to be another level on the C6 about 1.5" above the
before mentioned shift linkage that has a C shaped lever arm with a
small circular knob at the end of the C that seems to move freely
between two positions, always returning to the forward position if left
untouched. There seems to be nothing connected to this C shaped lever.
Has some spring or linkage fallen off this lever that just might be part
of my lack-o-third gear problem? Is it something between the column
linkage and this C shaped lever or is it between the gas pedal and the C
lever (as my dad described used to be a way to kick an old auto into the
next gear based on gas pedal depression)?
If this C shaped level is just for looks, then is there something else I
should be checking? I am scrounging around for books/repair manuals
that can help, but so far no luck.
Any help would be greatly appreciated,
John
bau...@ix.netcom.com
96 F150, 302, daily driver
77 E250 4WD, 460, C6, custom van!
hch...@mindspring.com
It could be one of several problems. You need a manual like the one
from ATSG that is available through NAPA or a transmission supplier.
One suspect is a frozen governor which is located in the tailshaft
housing. You may be able to remove the housing without removing the
complete trans to see if the governor piston moves freely.
Tom Padula
Without looking at it, this is only an educated guess, but I think the
C-shaped lever you referred to is the kickdown lever. There should be a
shaft connected to it going up behind the engine, then angling over the
intake manifold and connecting to the throttle linkage at the
carburetor. On the back of the manifold, it goes through a bracket with
a grommet in it that allows some slippage and acts as a pivot (sort of).
The shaft is copper-colored in my girlfriend's '77 F150 (also 460 & C6)
and if it's missing or bent or disconnected, it's possible that your C6
thinks it's in kickdown mode all the time, hence no third gear.
See if it's there, perhaps it came loose somehow or maybe the connection
at the linkage popped off. This is a pretty simple lever config, you'll
figure it out. If there's no lever, look at any Ford truck or van with a
C6, and some form of it should be there for comparison.
BTW, how did this situation come about? Did it just start doing this?
-tom
--
Tom Padula, Digital Media Audio Horde
Silicon Graphics Inc., Mountain View, CA
tjpa...@dowland.engr.sgi.com
650-933-7483, formerly area code 415
John Bauer III
Group:
Quick update on this silly C6 that can't get it up ... into third.
I checked the fluid again, and then again. Got the transmission as
level as I could (engine, trans, transfer case all mounted to angle down
towards the rear diff. to reduce UV joint angularity) and the fluid
level seemed a bit high (1/4" - 1/2" over full mark.) So, after pooling
over all the great advice I have gotten (thanks much folks), I picked up
a 76 Ford service manual from the library and a Fram filter/seal kit
from the parts store and get ready to get dirty ...
Don't have a vacuum gauge, but after removing the flexible hose to the
vacuum diaphragm, with the engine running, I noticed a suction, but also
noticed that the rubber hose had become very flexible and appears to
maybe caving in on itself under the suction. So, with high hopes,
replace hose with newer hose that doesn't noticeably crush under the
suction and drove around town. Still no third.
With advice to inspect filter and then move to modulator, I removed the
trans. oil pan last night. Holy Cow! Must have dumped about 6+ quarts
of fluid (including what was in the pan when I could finally get it
off.) Filled one Peak antifreeze container to the top plus three 1
quart oil containers with all the fluid. The Ford service manual says
the whole trans and t.converter hold 6.something quarts. (BTW, didn't
touch the torque converter, assuming it has ever more fluid in it.)
Now the big question, the service manual refers to too much fluid as
causing fluid aeration that will reduce the oil pressure (I assume this
will in turn cause the trans to not function correctly, but the text
does draw any conclusions from the low oil pressure) and cause fluid to
spill out the overflow vent. I have noticed no fluid coming out the
overflow vent. Does this mean I might have some minimal to serious
internal trans. problems due to the way extra fluid? What makes me
believe I might be in trouble is that the Ford service manual says I
should replace the filter, replace the gasket, put the pan back on and
fill it with 3 quarters of fluid and then just check level in case a
little topping off is required. Dumped like 6+ quarts, replace with 3
quarts, what the heck was the other 2 quarts doing in there? Too late
to strangle the guy I bought the van from ...
If anyone has any cool tips to help me out, I would greatly appreciate
it!
John Bauer III wrote:
>
> Group:
>
<cut to save space>
g-w...@ix.netcom.com
Hi John!
The kickdown lever one poster mentioned should be spring loaded at the
trans. Unless it's hung up somewhere from the carb down to the trans
linkage, it should snap back to a rest position on its own.
A bad/disconnected/wrong vacuum modulator could cause these problems,
but it should go into third at some speed, maybe 70 or so, when the
governor pressure overrides the modulator pressure.
Here's an anecdotal story that may or may not apply to your situation:
I rebuilt a C6 for a dear friend and co-worker to put in a street rod.
I used the same valve body that came with the trans, and installed a
shift kit, which I had done before to many other C6's.
My friend, Jack B., finally got the street rod running, drove it ONCE
around the block, and parked it for the day. The next week, he died of
a stroke at age 57. He never got to drive the rod very far, but at
least he got to drive it. What a sad day that was...
Anyway, his widow and son called me a while afterwards and said the
trans wouldn't shift into third. It shifted funny: Stayed in first in
1, shifted 1-2 in 2, shifted 1-2 in D. Should have started in second in
2, and should have shifted 1-2-3 in D. I tried all kinds of things, but
ended up swapping out the valve body with a spare I had lying around.
Fixed the problem right away.
Guess what kind of vehicle the trans came out of?
A van....
HMMMMMM......
Bad valve body, maybe? See if someone will loan you one. If it works,
then buy it from them. I would pay about $50 to $75 for a good used
valve body from a trans shop or wrecking yard. It should only cost
about another 50 or so to install, if you don't feel comfortable doing
it yourself.
I'm assuming that reverse works ok, right? (Reverse and third use the
same clutch pack.)
Good Luck!
Gerard
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