c4 issues

[Hubert Cumberdale]

Hello gentleman,

I finally (after 6 years) got my comet to move under its own power. Unfortunatly the transmission won't properly work.

The issues are and please bear with me as I know pretty much zilch about automatic transmissions.

When I start the car and go into gear,reverse,drive,whatever gear it works but I can't shift to another gear.Like if its in reverse first it won't go into drive after,but it does have a positive shift out of reverse.

When I drove it down the road it wouldnt upshift then the gear cut out.If I turn off the car and restart it,it will go back into gear.

The transmission worked fine.........ten years ago when I had it in my truck with the same motor.I never took it apart just put the motor/trans in the car as a unit.The only difference from then to now is a different shift set up,no kick down linkage,and a different trans cooler. I filled it up per the manual because it was a little low on fluid.I pulled the trans cooler lines to see if it was pumping fluid and it is.But the fluid is pretty milky(Im assuming from the torque converter).I was going to drain the fluid and replace the filter to see if that made any difference.But I figured I would see if anyone had some insight into the goings on with this tranny. Again I'm a big ol dummy when it comes to this.Hopefully I explained it well enough.
Any help is greatly appreciated

[poboyjo65]

There may be a drain on the torque converter ,drain that too if possible. it shouldn't be milky. I use F type fluid in my 76' C4

[popscomet]

I recheck my shift set make sure you got it all lined back up,as far as the kick down,that helps in shifting and in smoothness of shifts,but it will work without it,just not smooth and sometimes it won't down shift when you stop or slow down.....I'd put in frsh fluid and filter,when you have the pan off be sure and check your shift set up going into the driver's side

[popscomet]

I CAME BACK AND REREAD THIS,,you may have a dirty or sticking valve body,as well as what has already been mentioned,,,if that thing has been sitting for 10 yrs,it may have moisture or crud built up and just needs a good cleaning,driving it as much as possible may clear it up with clean fresh fluid or may not ,the valve body may need to come out and be taken apart and worked on....this is JMO...so don't hold me to nothing

[BJB]

When you mentioned the fluid being milky it got me thinking of when head gaskets let go , the oil and coolant mix to form a milky solution. Is it possible that your coolant lines have corroded over the last decade and you have coolant mixing with your transmission fluid? I'm assuming that the coolant lines flow through the radiator. Just a guess. Fresh fluid may not last if their is a problem there.

cheers and good luck.

Bruce

EDIT I googled about milky auto trans fluid and I may be correct however there is also the possibility of moisture build up over those years.

https://au.answers.yahoo.com/question/i ... 326AA9vKW7

[Hubert Cumberdale]

Hey guys,thanks for all the responses.Sorry to be getting back so late but I haven't been out in the garage much. I did end up pulling a cooler line, running the car and pumping out about 4 quarts of fluid.I also dropped the transmission pan and it had about an inch of mayo in it.So there was defiantly too much water in it.Luckily I didn't see any rust in the trans or filter so maybe some good news.However It only took three quarts when I went to fill it back up.After running it and going through all gears.Its defiantly better than before, it goes into all gears and shifts from first to second in drive but not third.So I may have to pull this c4 and pull the converter and see if its full of sludge as well.I was thinking about saving myself the hassle and taking it to a shop to get a hot flush done but I'm unsure if that would get all the gunk out.Either way I did some small burnouts today so that gave me a little joy.

[popscomet]

the converter should have a drain plug,,,think about what that valve body might have in it fter looking in the pan....jmo..pop

[BJB]

Burnouts? Wouldn't be stressing the transmission until you find out why it won't upshift to 3rd...

[popscomet]

Burnouts? Wouldn't be stressing the transmission until you find out why it won't upshift to 3rd...

won't hurt it ,BRUCE.......

[BJB]

With that crud still floating around..???? .his call then.

[Groover]

Yikes. Looks like a DQ MilkShake.

Believe you get to that torque converter drain plug by removing the dust plate (if you still have one) and rotating the flex plate and going through one of the holes. Might want to park it down hill so more fluid comes out as the plug is not on the bottom, it's kind of on the side of the torque converter.

[popscomet]

you might be shocked how clean the fluid might look coming out,after sitting over night and cools off and settles pop

[loman]

I think you are on the right track with getting it cleaned out. I'd do like you and the others have said and drain everything and change the filter. If it gets better but not quite all the way better, I'd drive it around 50 miles or so and get the trans good and warm. Then I'd change fluid a second time.

[popscomet]

Burnouts? Wouldn't be stressing the transmission until you find out why it won't upshift to 3rd...

won't hurt it ,BRUCE.......

HUBERT,DON'T TAKE THIS THE WRONG WAY !!!....but that burnout wasn't much ,was it?? mine has no traction devices under it and I can't do a burn out,as in smokeing the tires,mine will wheel hop to bad.....and that's the very reason why I did not put any traction under it,that way I won't be spinning the tires ...I just roll out and stab it and go to work on the 4spd and those 2 4's,and work off the RPM'S as well as the posi unit under it.....that was when I 1st built it way over 20yrs ago,now it's treated to match my age ...........................pop

[popscomet]

With that crud still floating around..???? .his call then.

HAVE YOU EVER noticed the crud in the bottom of an oil pan ?? it don't float around....you have to scrap it out...pop