7.3 with c6 questions

[Selahdoor]

Fairly new here. And I have a couple of questions about my truck.

It's an 89 F250 With 7.3 IDI diesel, and C6 transmission.

I'm not sure that it is shifting when it is supposed to. When it does shift from what seems like 1st to second, it shifts really hard, no matter where I have the gas pedal.

I have no idea if it ever shifts to third, but I think it must. Couldn't imagine it lasting long at highway speeds.

Speaking of highway speeds. At 60mph, the tach says it's at 3000rpm. That seems high to me.

And I was told that this engine doesn't like 3000 rpm for very long.

Does all this seem normal? Or am I risking the engine or trans?

I am going to try to figure out the gas mileage tomorrow. I don't think it's very good...

 

[79jasper]

Engine can easily run at red line all day long. No worries there.
RPM sounds right for that trans.
You may need to adjust the vacuum thing on the pump.

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[Selahdoor]

Engine can easily run at red line all day long. No worries there.
RPM sounds right for that trans.
You may need to adjust the vacuum thing on the pump.

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Thank you!

Vacuum thing on the pump???

What should I do a search for, to find out, what this thing is, how to know whether or not I need to adjust it, and how to adjust it if I do need to?

 

[rdoimages]

3000 at 60 is exactly why gear vendor units were popular !


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[rdoimages]

http://www.pirate4x4.com/forum/ford/906223-c6-transmission-modulator-valve.html


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[FarmerFrank]

You can run pedal to the floor all day as long as it doesn't get too hot. These old iron pigs don't mind running higher rpms for extended periods.

You rpms sounds about right on where mines at with a c6. Your shifting sounds like a vacuum problem to me also

 

[Clb]

+1 on the vrv valve

 

[Selahdoor]

Well, you who said the VRV... Were right on!

I have had this truck for two weeks, and I am already sick and tired of shops giving me conflicting information, and sometimes even downright incorrect information.

For instance, I was told that this truck never actually came from the factory with the c6. It did.

Also, was told that there was no throttle downshift linkage, because... where would you put it on a diesel? (I knew that was bogus when I heard it because even though a diesel doesn't have a carb, it most definitely has a throttle!

Too many others things for me to remember right now...

~~~

I am SO glad to have a forum like this one where I can talk to people who actually own and work on the same rigs. Thank you to all.

~~~

To get to the heart of it...

I am attaching a picture of my injection pump.

In it you can see quite clearly that there is a TV cable connected.

You can see just as clearly that there is NO VRV!!! Completely missing!

I crawled under and located the vacuum dashpot on the back of the transmission. It's there. There is a line connected to it. And it has a black indicator line on it. I just have no idea what it is connected to up above. I'll find that out later.

Right now, what I need to know, is... What are all the parts I am going to have to buy, to put this back into proper operation? The valve itself is obvious. But are there other parts as well?

Thank you in advance.

 

[Selahdoor]

Another quick question...

Let's assume the PO connected the dashpot directly to vacuum, somehow, after removing the VRV.

Is it going to damage the trans in some way, if I continue to run it that way until I get a new vrv set up?

 

[IDIBRONCO]

I don't think it would do much damage to your trans (although I could be wrong). These c6's were tough old birds as long as you keep fluid in them. As for the other parts, you need the two mounting screws and washers. If I remember right, there's a pin that goes through the shaft that the the valve straddles. It appears that your injector pump has one. It looks like the bottom of one showing underneath the plug on the front, driver's side of the pump. You also need to have a line to get the vacuum to the valve and then to the trans. From the factory, there was a rubber fitting that slid onto the valve and the lines both attached to this. If you remove the air cleaner and look, it could still be there. If not, you could just attach vacuum lines directly to the valve.

 

[cpdenton]

I went through a similar issue when I bought my truck.

A1989 model, just like my 1992 model, never came with a c6. They would have had an e4od from the factory. Older year models DID come with c6 transmissions. Some one had swapped a c6 in place of the original transmission in my truck as well. And they did it poorly. The vacuum was just tee'd into the vacuum manifold, so full vacuum at all times. It was in 3rd gear by 8 mph. It moved the truck, but not correctly.

Honestly, I cut my losses and swapped in a manual 5speed zf transmission. It made the truck where you can actually dive it on the highway, and ended all the problems with having a transmission swapped in incorrectly.

To make that c6 work, you have to have that vrv installed. Diesel c6 transmission did not have a kick down cable. See if that extra cable doesn't go over to a cruise module on the drivers fender.

 

[rdoimages]

My 89 has a C6, pretty sure it was factory.


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[Clb]

My 88 had a c-6
I have a fsm let me know if ya need something verified from it.
The c-6 is a tough *** slushbox' stupid simple in comparison to the e4od version.
Dial in the vrv and if its got an adj modulator dial it in also( just read up and play with the adjustments!

 

[rdoimages]

Thinking about it, I have an F-350 DRW, that might be a difference. I was under the impression that 89 was the year they changed to E4OD but I don't think mine was swapped in since it also had a gear vendors unit.

 

[riotwarrior]

My truck has a C6 a VRV and a KICK DOWN LEVER AND LINKAGE!

Bill has an instruction on how to serup the VRV IIRC

I WILL TRY AND DIG ip e copy I downloaded...

JM2CW