I haven't had an AT for awhile.
Here's the problem: I went and had the filter changed, and now it is giving me fits.
It goes into gear good and firm, but when I start to drive it and give it some throttle it acts like it jumped out of gear into neutral.
I replaced the modulator (hoping that would help--nope), my next step is to replace all of the rubber vacuum lines associated with the tranny.
The engine is acting like it has a vacuum leak when I start to accelerate, and then that's when the problem occurs.
It's got plenty of tranny fluid in it, it may be about 3/4 quart high.
I jacked the truck up in front to change out the modulator.
When I pulled out the modulator, about 5 quarts of fluid came out. That seemed like a lot to me, how much should have come out? I let it drain to about a trickle before I put the new modulator in.
Please Help, I need the truck this weekend, and I still have to pull the entire rearend and swap it with my other truck.

----Patrick

 

What kind of fluid are you using and what transmission?
JWR

72F250

 

C6, Type F
It's out of a 76 F250 2wd

----Patrick

 

When you say 5 quarts seems a little much.... Well if you mean that you didn't realize that there is 5 qts in a tranny, there is probably more like 7.5. I've got an old Fiat automatic, (that uses a GM Turbohydramatic 180) and it needed 6 quarts after a tranny swap, and that's a small tranny.

Or are you surprised that it came out of the modulator opening...

Bad modulators are usually indicated by the tranny not wanting to upshift regardless of where you are on the throttle. The tranny shifts to as low a gear that your engine can handle without going into redline when the modulator gets no vacuum.

You probably have figured this out by now.

Where did you have the filter changed? What do they think.

 

The C6 takes only Dexron II III, Or Mercon

 

Only the newer C6's take the dextron mercon later ones use type F. I belive ford switched to mercon in 1977-check your dip stick it will tell you what type of fluid to use .

 

Found out what the problem was.
Apparently, there are 3 different filters used on the C6.
Standard, medium (has a D shaped hole for pickup) and 4wd depths.
Mine is the medium depth.
The kid at the parts store only found listings for two of them (standard and 4wd), and sold me the 4wd one.
I had told them it was a 2wd tranny out of a F250 when I got the filter in the first place.
I didn't know any better, I thought that it was an updated version of the filter.
What was happening, was that the rubber O-ring for the pickup (4wd filter) was sealing itself to the bottom of the trans pan. So when I stepped on it, and got the suction going it sealed itself to the bottom and bingo, no fluid goes through.
Since this pan is deeper, it holds more fluid. 6-7 quarts needed for a filter change. I think the guy at the tranny shop said it will take 11 to 13 quarts if I drain the converter.
Strange part is that the manager of the parts store said that filter is used on '78+ C6's. (fram ft1037 is what I needed, the one they originally sold me was a fram ft1055)
I've had problems with this store before, so I should have known better.
Needless to say, I went to a different parts store and got the correct filter (not a fram this time)
Dipstick does say Type F. (first thing I checked)
So thanks for all the help.
Now to swap rearends.
This one leaks from the axle seal and pinion seal.
I have my donor (66 F100, everything measures up) that I had put new seals and wheel bearings into about 2 yrs ago.
First thing in the morning......The JOYS of owning an older truck.
Gotta love them

----Patrick

 

A good parts store is worth it's weight in gold!
Your comment "the KID at the parts store" tends to make me think you had gone to a chain store.
When I first got my pickup it had a small leak from the oil filter, just a few drops now and then. Then one day I went out and there was oil all OVER the driveway! Turns out that the filter, which mounts vertically on a '68 390, was hitting the crossmember and had cracked. Got the old filter off, got the number off the filter and headed to the chain store to get a shorter filter. The KID insisted that that was the only filter that would fit because that is what his computer listed for the engine.
I then went across town to one of those real auto parts stores where they still have the books in the holders on the counter. I told the clerk what had happened to my truck and without even looking in the book he said "Oh, you need a 3/4 quart Dodge filter." He cross referenced the filter number I had to a 3/4 quart Dodge filter and it's working fine ever since.
So I know what you mean about less than competent auto parts people,

 

I use the ford FL300 it is basically the dodge filter but it says ford on it

 

Yep, FL300 is a short FL1A. Funny its almost never listed correctly. Usually there is no mention that you have to use it on Crown Vics and Mustangs with the Police Package. (Oil Cooler)

 

Choice of a parts store can be as serious a question as whether you drive a F-100 or a T-100, but I tend to like either Autozone or Kragen partly because of the price, but mostly because I get to be the kid behind the counter.

Autozone or Kragen/Checker/Shucks all represented by PartsAmerica.com have excellent websites and a much better selection online than in the store. You can see who makes the different parts and compare the prices much easier. Normally, the stores only carry one version of the part. And it's great when I have to order for example everything for a suspension rebuild on my F-100, because I get to see a much better selection than what they have in the store, and I can be far more confident that I'm getting the right part versus whether Junior ordered it, and all of those parts get delivered.

Sure you have to wait a while, but when I'm doing that serious service where I'm doing tune up, LOF and cooling system, it almost never fails where they never have that one part, and I end up waiting anyway. And even if you are in a hurry and want to pick up the part in the store, I look it up on line first anyway to see if they carry it in the store and whether the part I have is the one that Junior found. I been in there where Junior can't even find the part on the computer, but I just give him the in house part number that I got off the website, and suddenly he can find it on the shelf.

And no I have no affiliation with either chain, it's just that even when you don't order online, using the website can help you get the right part.

 

It was a privately and locally owned parts store.
Usually, I would go to Napa becuase they give me better deals, but they had closed their local store.
We also have a CarQuest here, but more recently I try to give my business to the locally owned stores instead as much as possible. I ended up going to a different locally owned store with much more experienced sales persons.

----Patrick