I'm not a trans expert in the slightest so I figured I'd ask to get some ideas on this one.
On the first shift of the day, when the tranny is cold, my c6 will shift late into 2nd gear. If I allow the tranny to warm up (10 min or so in neutral) it will not do this. I can shift it manually from 1 into 2 and it engages smoothly. After the first shift, the c6 will seemlessly shift without problem for the rest of the day.

C6 is in a 91 E150 and has 183K on it with no rebuilds or metal in the pan, however fluid is a bit dirty and i've changed it 3 times between 110k and 183k.

Has anyone encountered this before or at least have a theory?

thanks,
-jeremy

 

first, keep up your fluid changes and do them every 12,000 mi. and at proper level
how late is late? #1 -does it hold in 1st until redline under light throttle and shifts to second or #2 - is it more like it holds 1st until 2,00rpm's and shifts under light throttle? and is the feel of the shift soft to normal? if it is #2 then this could be considered normal. just keep paying attention like you have been to see if the delay gets longer. also did you notice this when it was warmmer out and became apparent when it became colder? as far as theories- it's cold out,engine is cold, a little less power until it's warmed up, tranny is also cold , now you just might need a little more pedal to get the beast rolling first thing and the modulator will see a little less vacume and hold out on a shift and after this all will seem normal
yes i've encountered this with almost any auto tranny i've driven when i drive off right after starting it on a cold morning- light throttle of course. my friends 90 F250 with the 460 and C6 allways did this, my '90 F150 302 w E4OD does this and that's how the stratidgy in the ECU handles it.
since your c6 is non electronically controlled it's seems to be the nature of the thing. just remember to keep the fuild clean and at proper level and have someone you trust to make sure the bands are adjusted right. i know the C6 will have abnormal delay into second if second gear brake band is out of adjustment but this will happen all the time.
hope this helps
Mike

 

My symptoms are more like #2 and more so since the temps have dropped. That makes me feel a whole lot better. I don't ever remember it doing this last winter. I'm going to check the band adjustment as I read in the Haynes manual that it can be adjusted from the outside. I have a feeling that the band is in need of adjustment.

thanks again
-jeremy

 

It isn't abnormal for a c-6 converter to drain off after sitting for a while. However with that many miles it's probably getting close to a rebuild. The stuff in the pan is likely to be clutch material.

 

Sticking valve or partially blocked passage in the valvebody?

Sounds like rebuild time...

 

mark a.
there's been nothing in the pan with the exception of fluid for the life of this trans. No metal or junk.


Torque1st
I thought if it was a sticking valve or partially blocked passage in the valvebody, that it would shift late all of the time or at least randomly. My problem is that it only does this on the first shift of the day. Every shift up or down for the remainder of the day is smooth.

thanks

 

jermey, check your vacuum line to the modulator for loose fit, cracks, old age.
A good place to loose vacuum siginal when the rubber hose is cold and hard. Also check for trans fluid in the line at the modulator while your there. Ford transmissions are sensitive to foreign particles vs GM that will shift while passing dirt. Carl. .........o&o>........

 

thanks Carl Beemer. I'll check that out and report back.