C4 diagnostics and data

Discussion in 'Transmissions' started by PaulS, Aug 20, 2008.

  1. George20

    George20 New Member

    Joined:
    Feb 26, 2012
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Mississippi
    Vehicle:
    1970 F100 Truck
    Still Have Problems

    Hello. This my first post. I recently rebuilt my 1970 c4 because it was all original and slipping when shifting into 3rd under heavy throttle. Its behind a fresh rebuilt 302 that is only slightly over stock hp. (Four barrel, alum. intake, matched cam.) I replaced both sets of clutches and steels and all the thrust washers and all the rubber seals on both pistons in the drums. Also the servo and pump seals. I did not go into the front pump or disassemble the valve body. The problem is that is still slips shifting into 3rd under hard throttle. It also now slips shifting into 2nd under hard throttle. It will also shift into 3rd on its own while the gear lever is still in 2nd when rpms reach the low 4000's but will downshift back to 2nd when you let offf the throttle and slow down. When you leave in D and drive normal it shifts fine thru all three gears. What did I do wrong or neglect to do during the rebuild? Thanks in advance for any info....George
     
  2. PaulS

    PaulS Member extrordiare

    Joined:
    May 3, 2004
    Messages:
    4,858
    Likes Received:
    8
    Trophy Points:
    0
    Location:
    Seattle area
    Vehicle:
    1966 Mustang, 1972, 73, 73 and 73 Mavericks
    Since my second operation I am unable to do much so I am providing my anti-flare kit designs and instructions for anyone to use for PERSONAL use only. It is not OK to sell the kit unless you have written permission to do so and I have provided that permission to only one individual - Greg.
    You can build your own kit and install it in your transmission for free. No commercial use is permitted by anyone other than Greg.
    Paul
     

    Attached Files:

  3. captainmack

    captainmack Quad Door

    Joined:
    Mar 15, 2006
    Messages:
    498
    Likes Received:
    18
    Trophy Points:
    112
    Location:
    Marina del Rey, CA...on my boat
    Vehicle:
    1972 4 Door Comet, 200, C4 1970 Dodge Coronet 1975 Econoline 250
    Glad to hear from you Paul, hope you're hanging in there.
     
  4. Speechless35

    Speechless35 Speechless35

    Joined:
    Jan 24, 2012
    Messages:
    57
    Likes Received:
    0
    Trophy Points:
    35
    Location:
    Naples,Fl
    Vehicle:
    1976 Ford Maverick Sedan
    Sometimes When I Shift My Cat To Park My Car Tends To Move Forward A Couple Yards Before Stopping..... WTH Is Wrong?? 76 Ford Maverick Sedan Automatic
     
  5. Speechless35

    Speechless35 Speechless35

    Joined:
    Jan 24, 2012
    Messages:
    57
    Likes Received:
    0
    Trophy Points:
    35
    Location:
    Naples,Fl
    Vehicle:
    1976 Ford Maverick Sedan
    Sometimes When I Shift My Cat To Park My Car Tends To Move Forward A Couple Yards Before Stopping..... WTH Is Wrong?? 76 Ford Maverick Sedan Automatic
     
  6. Speechless35

    Speechless35 Speechless35

    Joined:
    Jan 24, 2012
    Messages:
    57
    Likes Received:
    0
    Trophy Points:
    35
    Location:
    Naples,Fl
    Vehicle:
    1976 Ford Maverick Sedan
    Sometimes When I Shift My Cat To Park My Car Tends To Move Forward A Couple Yards Before Stopping..... WTH Is Wrong?? 76 Ford Maverick Sedan Automatic
     
  7. Craig Selvey

    Craig Selvey Indiana State Rep - MCCI

    Joined:
    Mar 9, 2002
    Messages:
    18,218
    Likes Received:
    1,308
    Trophy Points:
    878
    Location:
    Albany, Indiana
    Vehicle:
    1972 Maverick Grabber - Color: Orange Also, 1976 Ford Maverick 4-door, 1977 Mercury Comet 2-door.

    A couple yards....that is like 6 feet. Are you sure it is moving that far?
     
  8. Speechless35

    Speechless35 Speechless35

    Joined:
    Jan 24, 2012
    Messages:
    57
    Likes Received:
    0
    Trophy Points:
    35
    Location:
    Naples,Fl
    Vehicle:
    1976 Ford Maverick Sedan
    Ok ok it moves a "little" bit forward after I put it in park
     
  9. Craig Selvey

    Craig Selvey Indiana State Rep - MCCI

    Joined:
    Mar 9, 2002
    Messages:
    18,218
    Likes Received:
    1,308
    Trophy Points:
    878
    Location:
    Albany, Indiana
    Vehicle:
    1972 Maverick Grabber - Color: Orange Also, 1976 Ford Maverick 4-door, 1977 Mercury Comet 2-door.

    That is normal.
     
  10. sspargo

    sspargo New Member

    Joined:
    Dec 16, 2012
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Auckland, New Zealand
    Vehicle:
    1965 Ford Mustang, 289, C4
    Seems there are some very knowledgeable folks about C4 transmissions on here, so was wondering if you could help me with the following.

    My C4 slips on the upshift between 2nd and 3rd under low acceleration when it is warm, seems to be fine once it is in 3rd, no slipping at all.

    It does not do it when it is cold, or under a decent amount of acceleration, also, not sure if it is related, but the shift from 1st to 2nd is pretty hard, and seems to get worse when it warms up too, anyone have any ideas on what may be causing this?

    Thanks, Scott
     
  11. xagt351

    xagt351 New Member

    Joined:
    May 3, 2013
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Lower Hutt, New Zealand
    Vehicle:
    Ford Falcon XA GT
    I am living in Lower Hutt New Zealand and have a problem with my C4
    I bought a reconditioned C4 and we modified it to take a B&M Transpak kit Performance mods done to trans. I have fitted to motor and installed. Seems to get second gear then when you take your foot of the gas shifts down to 1st and stays there. I have reverse. I thought it maybe the ratchet shifter needing tuning so I reversed up the drive so I can jack up. When I stopped the car and turned it off I heard fluid pouring out and looked under car to find the intermediate servo had pull the thread on the bottom bolts that hold it in place and trans oil was pouring out of there. I have had no luck finding anyone that knows what has gone wrong. We think we may have a valve around the wrong way.
     
  12. jbates93

    jbates93 New Member

    Joined:
    Mar 23, 2013
    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    0
    Vehicle:
    1975 Mercury Comet
    i just dropped a 302 into my 1975 comet with a c4 and it will not shift out of first. even if i shift through the gears manually it stays in first. it was working 2 weeks ago before i put in the 302. any advice??
     
  13. wp100

    wp100 New Member

    Joined:
    Aug 18, 2013
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Farmington Hills, MI
    Vehicle:
    1965 Ford Falcon
    Hi Paul, I have read through your posts and really appreciate you sharing your C4 knowledge and willingness to offer help others to resolve their issues! I'm hoping you can help me out with mine. I've got a 1965 C4 in a Falcon (sorry to bring a "foreign" car to this Maverick/Comet site) behind a 289 that has run really well after a miner overhaul I did three or four years ago (replaced bands and some thrust washers to bring the tolerances back to specs, the clutch packs looked good at the time). A month or so ago it started to delay three or four seconds going into reverse, but only after it warmed up. When first started, when its cold, it goes into reverse immediately. All the other gears engage properly, including low gear, even after it warms up. I'm thinking it could be the reverse band servo piston, but was told by a friend that it could be a problem in the valve body. Given your knowledge of C4s, I thought I would come to you for advice. Thanks for any assistance you can provide.
     
  14. wp100

    wp100 New Member

    Joined:
    Aug 18, 2013
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Farmington Hills, MI
    Vehicle:
    1965 Ford Falcon
    Thanks for the reply, Don. I have read all of Paul's post and could not find my "reverse only slow engagement" issue. However, I didn't notice his last post was back in June 2012, I too hope he's doing well. I'll continue to watch for any other member to reply. Thanks again for your quick reply.
     
  15. danford1

    danford1 Member

    Joined:
    Sep 2, 2007
    Messages:
    91
    Likes Received:
    2
    Trophy Points:
    23
    Location:
    White Lake, Michigan
    C4, 1-2 shift isn't right

    I have a 66 Fairlane, 289, C4 green dot shift pattern.
    Rev is fine. 1st is fine. D1 where it starts in 2 nd then shifts to 3rd is fine.
    When in D2 green dot, if I take off really easy it will shift to 2nd ok then later to 3rd.
    If i take off quicker in green dot it revs up high then either shifts to 3rd or if it shifts to 2nd, it doesn't feel right, it is mushy. I let up on the gas and it seems ok.
    I can start in green dot and accelerate then manually shift to white dot and it goes into 2nd OK then shifts itself into 3rd.
    My real issue is the automatic shift for 1-2 isn't right.
    What can I check.
    Oh, fluid is full and see through red, not burnt. It smells like normal good fluid.
    Car has 95,000 miles, i don't have any history of the trans. The clean fluid tells me it at least had that changed before.
    This is a new to me car and it shifted OK a couple days ago and now is acting up and getting worse.
    I do manual shifting now so I don't cause any more damage.

    Danford1
     

Share This Page