C4 is probably shot - HELP.

[MN69Grande 203]

Fun times.  I was out for a drive this afternoon in the stang.  After about 90 miles the car started having trouble shifting into 3rd.  Once it shifted it seemed to run fine, but it was rev'ing really high and once I let off the accelerator a little it would shift.  I started heading home.  10 miles later it stop shifting into 3rd all together.  Luckily I was close to my parent's lake house (50 miles from home) and limped the 5 miles there at 40mph in 2nd.

Once I stopped I left the car idling and checked the transmission fluid.  Full, good color, no burnt smell.  But I did notice a small pool of oil on back of the the intake manifold.  Using a flash light I traced the oil to either the valve cover or maybe one of the intake manifold bolts.  I replaced the manifolds this winter but was a little suspect they stayed in the correct place when I set the manifold down.  The motor was running good, the oil stayed clean, and I didn't see any oil out of the motor until today so I figured I got away with it.  Is it possible pressure, heat, etc finally caused an intake manifold leak resulting in a loss of vacuum and hence shifting problems?

I couldn't test the vacuum at the modulator.  I'll trailer the car home tomorrow.  I'm just hoping it's just in need of a new intake manifold gasket or vacuum modulator.  I really don't feel like pulling the transmission this winter.

 

On the bonus side I saw a killer Red 69 Mach 1 up in Glendale MN today.  So I got that going for me which is nice.

[MN69Grande 203]

C4 for automatic by the way if that matters.

[LoneWolf2U 136]

Look for the simple things first,  Check the linkage for the kick down for correct adjustment and spring return.

From you post it sounds like it has stuck its self in passing gear mode.

[MN69Grande 203]

10 minutes ago, Mach1Rider said:

Look for the simple things first,  Check the linkage for the kick down for correct adjustment and spring return.

From you post it sounds like it has stuck its self in passing gear mode.

Yeah that was the second thing I checked after the fluid.  It seemed to be moving freely from playing with it and watching it from above.  I was planning to make a better inspection once I get it home.  I didn't feel like laying in the dirt as the sun went down.

[RPM 1,190]

31 minutes ago, MN69Grande said:

  So I got that going for me which is nice.

Thank you. Nursing a sore back,  I needed a laugh.

On a related note, if you use long all thread on the outer catty corner intake bolt holes on a sbf, it sets the intake down without moving the gaskets. 

[MN69Grande 203]

27 minutes ago, RPM said:

Thank you. Nursing a sore back,  I needed a laugh.

On a related note, if you use long all thread on the outer catty corner intake bolt holes on a sbf, it sets the intake down without moving the gaskets. 

You know some how I ended up with all bolts.  If I remember correctly the car originally had 4 studs mixed in with the bolts that kind of kept everything in place.  I think they had to get replaced with the updated block. Some 5.0 stuff doesn't match the 302 stuff and it seems to mostly be bolts.

 

I think there is also some adhesive made exactly for this purpose.

[barnett468 418]

no, a leaking intake will not cause shift problems.

[MN69Grande 203]

36 minutes ago, barnett468 said:

no, a leaking intake will not cause shift problems.

Barnett468 always with a definitive answer.  Good thing I ordered new vacuum lines and modulator.  Hopefully that will bring back 3rd gear.  I was just kind of thinking out loud.

[barnett468 418]

lol.

 

of curse this does not mean the intake is not leaking, however, if it idles fine it likely isn't. for the intake to leak enough to affect the trans shifting it would literally have to be missing a gasket on one side at which point it wouldn't run anyway.

[MN69Grande 203]

So I changed the vacuum lines and modulator today.  But it was raining too much for a test drive.  This is the old modulator I'm guessing it got bumping one of the last couple times the tranny was out.  Which means this little guy trucked on for anywhere from 2000-5000 miles all deformed like that.

[Bob & Sue 110]

That must have been fun to get out wobbling around. 

I have a new one that I haven't gotten around to replacing yet. Anyone know what the difference is between the green, white stripe etc mines green could hardly see the color ring? 

Did it hit the case trying to remove it?

[MN69Grande 203]

Oh yeah it was a ton of fun.  The pan is in the way of using a wrench.  But everything I read said hand tighten only.  So I was able to get it out without tools.  But there is no room to fidget around.  And having it wobble as you say made it scrape a bit.  The stripes indicate if it is push in with a clip or screw in.  Also fmx is different.  Just get the same color and you should be good.

[MN69Grande 203]

So I took a test drive today after the car sat for a week and I changed to modulator and vacuum lines.  I had 3rd gear during the test drive, though it did shift fun a couple of times.  So I decided to drive the car from my parent's lake house back to my house ~50.  30 miles into the drive I was in 3rd gear and all of a sudden the revs shot up and I couldn't really go faster than 60.  So I drove a couple miles pulled into a parking lot and let the car sit for 30 min.  Started to drive again and still no third gear.  Fine I thought I'll limp down the road at 35-40 in 2nd.  5-6 miles later and I can't go faster than 22 mph and the revs were higher than they should be at that point.  I crept up a hill at 3000 rpm and doing 18 mph so I could pull into a big parking lot at a regional park.  Called AAA and got towed home 2 hours later (thanks for the speedy service AAA).  

Fluid levels are ok, modulator is brand new, vacuum hoses are good and unobstructed, fluid was not gushing from any place.  So are there any easy things to look at or does the transmission just go to a shop?

[mwye0627 44]

I'm not sure about a C4, but about 40 years ago I was about 150 miles away from home in a friends car. It was a Camaro with a TH350 trans and we had very similar symptoms. Like you said, after about 35 miles all we had was first gear. Once we got to a certain speed where the transmission should have shifted into 2nd, it just went out of gear completely as if it were in neutral. We drove the rest of the way home with our flashers on at about 22 MPH. We got pulled over by the Ohio State Patrol on I-75 for "Going too SLOW", LOL!!!

As it turned out, it was the governor inside the transmission that went bad. That was a pretty easy fix on a TH350 trans.

Hopefully your new vacuum modulator / throttle valve will fix your problem, as it controls line pressure for the clutches and bands.   If not, then you may want to look into cleaning your governor.

I looked up some information on the C4. It looks like it should be fairly easy to get to by removing the driveshaft and speedometer cable gear. Then remove the tailshaft housing. The governor slides over the output shaft and is bolted to the governor distributor, which supplies the pressure to and from the governor.

Here are links to a couple of pictures and a video describing how to disassemble, clean and reassemble the governor.

Video url: (remove quote marks, Vimeo wouldn't allow embedding)  "https://vimeo.com/122806383" 

http://www.saacforum.com/galleryc/displayimage.php?pid=1564&fullsize=1

http://www.saacforum.com/galleryc/displayimage.php?album=119&pos=2

http://www.diyford.com/assemble-ford-c4-transmissions-cruise-o-matic-select-shift/

The last link is for complete assembly information for a C4.  Toward the end of the article is information about the governor.  You will see that it recommends putting a governor filter screen in the governor distribution block to prevent dirt and crud from getting into the governor causing the valves to stick.

Good luck and I hope you get your problems sorted out fairly easily!!!

Mike

[MN69Grande 203]

Thanks Mike that looks like good information.

 

I found this site too: http://www.diyford.com/ford-c4-c6-transmission-trouble-shooting-guide/

It agrees with you that a 1-2 shift could be Governor related, but 2-3 shifts which was the original problem are different.  I wonder if the the parts below got damaged and clogged up the governor.

"No 1-2 Upshift

1. Governor issue, stuck valve.
2. 1-2 shift valve issue.
3. Intermediate band servo not applying.
4. One-way clutch defective or improperly assembled.

 

Slips at 2-3 Upshift

1. Improper direct clutch clearances.
2. Damaged direct clutch piston seal.
3. Leaking iron-sealing rings."

 

looks like I would need to inspect more than just one part of the transmission.

[danno 128]

If you decide not to tackle this, there is a guy at kennedy Transmission on east lake street in Minneapolis who has worked on my car.  Nice, honest guy who appreciates old cars.  I think his name was Mark, I can get it if you want someone else to do it.  You might talk to him at least, he will give you some ideas.  

[JD08 42]

I have the exact same problem with my 90 AOD. I was told it's most likely the direct clutch. My fluid was burnt but I drove it a little further than you did. 

[MN69Grande 203]

Danno - Thanks for the recommend.  I might have to call them up.  Tearing down the transmission is probably a little more than I want to get into.  I'm starting to think the motor is probably just putting out more horsepower/torque than the current build of the transmission can handle.  Do you think your guy would be able to do a more performance oriented build?  I've used Prove Force out in Maple Grove and they are awesome, but you pay a price for awesome.

 

JD08 - I honestly didn't try smelling my fluid after the second break down.  I'll have to do that this weekend.

[danno 128]

I will stop by an talk to him.  I am not sure if he can do a performance kit, but I would guess it is possible.   I also am not sure if he would be a better price than Prove Force, but he was reasonable with me.     It has been a couple years, for all I know he is gone.  Any mechanic who knows these trannys  is old, as he is.   Paul Brand used to recommend him, if you remember his talk show.

[MN69Grande 203]

13 minutes ago, danno said:

  Any mechanic who knows these trannys  is old, as he is.  

I've found this to be more and more of a problem.  And there are to of people full of BS that say they can do this stuff.  That's why I'm so glad this site exists so much good information on here and people to help.

[danno 128]

I stopped by the shop tonight, they have a 65 vette and a 32 coupe in in now that they are working on. Mark is on vacation, but the other guy was there, and is probably as reasonable as Mark.  I asked about upgrade kits, and he is aware of them, but said most times you are better off going to an all out better tranny, like a C6.  Stop by and talk to them, and mention Danno with his 69 that they worked on last year. 

[tim42 13]

MN69Grande and danno, for what it's worth I've tried to have that shop do the tranny on my '99 Sable wagon.  When the tranny is hot in stop and go traffic it surges going into low gear.  And sometimes has trouble going into 2nd gear.  I've had a tech with me on a test drive and it did all the things I mentioned.  I talked it over with Mark and left it for repair.  When a different tech was going to do the job he couldn't duplicate the problems.  So they didn't do it.  I want them to do it but they won't do it   So we decided it would have to totally fail.  As far as the C6 goes is the small block C6 the same horsepower drain as the big block?

[MN69Grande 203]

Thanks for the follow up Danno.  I'm going to try and hit 3-4 shops this weekend.  Proven Force in Maple Grove,  Affordable Transmission & Performance in Northeast Minneapolis, Kennedy on East Lake, and a local shop we've been getting the majority of repairs done (he seems to get a lot of classic work out here).  To be honest if I were to go the step of changing the type of transmission and all that is involved there I will do a five speed swap.  Probably a Tremec as I still kick around the idea of a cam swap so I want a little power handling left above my current needs.  I've also seen online 3 or 4 crate C-4s that can handle 450-750hp (Performance Automatic, Animal Performance Transmission, TCI has one, etc) so that maybe another option. 

 

tim42 - bummer about your sable.  I guess in my opinion it is better they didn't just take your money, pull it apart and put it back together with no change; many shops would do that and charge you twice.  I've been reading reviews on some other local places and it seems common for good shops to turn down work rather than take on something that might cost the car owner exorbitantly by going down a rabbit hole.  Just my 2 cents.

[danno 128]

Tim42, that is an interesting story. I work on electronic aircraft sensors, and we get them returned to us all the time because of a problem. We test them and they work perfectly.  It is impossible to fix something that is working perfectly when we examine it.   Maybe Mark thought the same?  I would think, though, that for a transmission a complete teardown would reveal the problem.  Maybe the expense of a complete teardown was not something Mark considered?  He wants the problem to point in one direction first.

 

[MN69Grande 203]

Only had time to visit one shop last week.  Bid came in a few hundred higher than I expected.  The big difference came with them pushing a custom built torque converter at $600-700.  From the bid:  "To handle the HP we would have to use a Billet Converter, and performance internals."  

The last one I got at summit for $350.  Of course I wasn't super happy with the last one and wanted to go with a higher stall speed anyway.  Does this seem reasonable?  

Still need to hit up a couple other places.