My truck has been doing really good lately, got the FSV working and have made a couple 400 mile trips in it. Last one though when I got back into town I noticed that when I started from a stop it would shift really late into 2nd gear. I replaced the modulator valve and it did not fix the problem.

It just started doing this. 40 miles prior getting onto the freeway it shifted smoothly as ever. Fluid is not burnt either. It's always been a hard shifter from 1st to 2nd, but this is new behavior.

Any ideas? Or should I just start planning on a rebuild?

 

check vacuum. i bet it is only around 17 or 18 inches. this will mean you pump is going. you should see closer to 21-22 inches on a good pump.

 

^^^That. And check the condition of all the hoses that connect the line to the tubing that supplies vacuum to the modulator. There's also adjustments that can be preformed to the modulator and one of the transmission's bands. If you so all of that and there's still problems then your tranny is most likely dying.

The good news is, if it is going out, the C6 isn't hard to rebuild if you're mechanical. If not they don't cost a whole lot, (comparatively), to rebuild.

FWIW: DON'T go to AAMCO. NEVER! Let me repeat, DO NOT GO TO AAMCO!!!

 

i would rather hammer on my private parts all day long with a 5 lb lump hammer than ever take a transmission to aamco again.

in defense though, i was 21, and needed the trans fixed rite away, so it took it there.
and ended up having to buy another truck because it took them 4 months to fix everything they screwed up.

 

Don't forget to look at your VRV on the injection pump as a possible cause. They cause weird issues I thought I had one where 2nd ear was out, turns out the VRV was on the fritz.

 

How do you test the VRV?

 

first check you vacuum.

this is how to set the VRV
https://www.ford-trucks.com/forums/s...6&postcount=12

 

Did some testing. I only had one vacuum gauge and a Mityvac without a gauge on it so I wasn't able to properly test the VRV... hopefully what I did will make up for it.

I connected the gauge directly into the vacuum system and it read 25hg of vacuum, so we know the pump is good.

I then hooked the gauge in between the VRV and modulator and went for a drive. It was reading about 15hg of vacuum at idle, however at WOT it would go down to zero vacuum.

Is the VRV shot? Or do I need to get another gauge so I can do a proper test as described above?

Looks like I'll still have some room to adjust my VRV but the hard line to the injector pump prevents me from getting a phillips screw driver in there. It's adjust right in the middle of the range. I can get it with a 90 degree phillips if I can round one up somewhere..

I'll post a video of my drive. For what it's worth I have no vacuum leaks, I can leave it parked for a week and still have plenty of vacuum to work the pedal.

If the VRV is shot my only other thought is the intermediate band. I drove the truck 100 miles yesterday(rural highway = no shifting once in 3rd) and the trans didn't get above 150f. Fluid is clean and smells fine too.

 

I know this is after the fact, but for anyone reading this post with a similar issue in the future, here you go. You can tell if you have a vacuum issue while you are driving, by if you can manually shift thru the C6 gears on the tree. If you can manually shift, then you probably have vacuum issues. If not, then you may have internal issues. Also, if you have no climate control or brake power assist, then you probably have a pump failure. If you have climate control and power assist but no or limited automatic shifting capability, then you probably have a problem in a vac line, or the VRV.

 

Well that makes me even more sure it's the trans... Manual 2nd starts in first and if you down shift it from 3rd it just acts like its in neutral.

 

Decided that I'm going to have it rebuilt. First quote was $1400-$1600 with the trans in the truck. Does that seem high?

 

Way to high. Around here a rebuilt c6 goes for $500-$700. And you cant rebuild it in the truck.

 

That seems a bit high... what kind of parts are they using? A rebuild would be $$$ if you had to replace hard parts (planetary gears, pump, valve body, shaft...) but a seal and clutch kit shouldn't be much more than 300-400 for a decent overhaul kit

 

i think what was meant by that was; $1400-1600 with trans in truck.meaning having it pulled,rebuilt and then installed back in the truck.the converter should be replaced too.the price could also include that.
i shelled out over 3k last winter for the same done to an E40D,so for a c6 that's fair,but i never do it.i'd buck up and make the swap to an updated trans.either the zf5 or e40d unless it's something not driven too much per year,then id just toss in a used c6 and run 'er.

depending on truck condition,it may be time to weigh options of making a truck swap too at time of costly repairs like these.always keep an open mind and think objectively as you look around ebay/local auto mags/GL to see if selling and rebuying doesn't get you more bang for buck than simply fixing ol betsy does.

 

F250 do you hate the OP for some reason? C6 to an E40D??!!! That's like trading in a Lincoln for a Metro!! C6 is the upgrade!

To the OP, does sound a little high, a C6 rebuild used to be $600 to $800, but things have been going up in costs quite a bit in the last few years. Also, as mentioned above that price may include hard parts as well as the soft. Just make sure it's a good shop.
And not Aamco.