Project "Uncle John" 1969 Chevy c20

[brycerowdy]

Lets get down to the point. I got this truck as a Christmas present in 2011. Since that I have done a little work to it. I have got the 396 running,and cleaned out the interior.

[brycerowdy]

I haven't worked on the truck in a while but I will keep the 396 but will put in a 700R4.

[Tinkermc]

well I like your santa much better than mine. Welcome to the forum

[brycerowdy]

Thank you

[truckzilla]

I've been following your dad's build of Fred and look forward to seeing what you do with your 'farm truck'. How's that 396 running? I'd have to agree on the 700R4. Do you know what your rear gearing is by chance? My dad put a 700R4 in his '70 and it really dropped his highway RPMs in overdrive more than he wanted due to his truck having such low (numerically) gearing in the pumpkin. And post more pics if you're able. Good luck and welcome to the gang!

[brycerowdy]

Truckzilla the 396 runs great the only problem right now is that it won't idle. I think the rear gears are 4.10. and Cool!

[brycerowdy]

Ok i just got a new laptop so i will post some more pics tonight.

[brycerowdy]

Cupholder!!! Thanks Larry!

[brycerowdy]

I got the cupholder installed and the 396 at an idle.

[brycerowdy]

Ok, so I drove the truck up and down the driveway on Saturday and the 396 was awesome. I need to get a tranny shift module put in so it will shift out of first gear. Other than that, the truck has been awesome.

[truckzilla]

A 4.10 rear gearing should go very well with the 700R4! If the trans is stuck in first gear, it sounds like it maybe the module is stuck in failsafe mode. That lets the driver limp home rather than leave the vehicle stranded. A transmission shop should be able to correct that I believe.

[truckzilla]

Originally Posted by truckzilla

A 4.10 rear gearing should go very well with the 700R4! If the trans is stuck in first gear, it sounds like it maybe the module is stuck in failsafe mode. That lets the driver limp home rather than leave the vehicle stranded. A transmission shop should be able to correct that I believe.

When my 700R4 did that, there was some issue with the electical connection like water had gotten in it or something like that. That was on a '96 model though. It might be the TV cable needs adjusting or some other small item.

[truckzilla]

On another board, one poster responded to the same problem someone else was having with this:

First check tour TV cable and make sure its adjusted right. Next you will have to pull the valve body and check the TV valve and the shift valves and make sure nothing is sticking. Also your governer valve could be stuck. Pull the governor and look at the gear and make sure its not chewed up. Also hold the governor so the gear is pointing up and move the weights open and closed and see if the valve moves up and down.

With my issue of the trans sticking in first gear, I think because of the year of it, it wasn't a 700R4 after all but the electrically controlled version of it known as the 4L60E. So the electrical plug and module matter may not even apply for you if your's is a pre '93 transmission.

And from another site, they say:
The governor on a 700R4 automatic transmission helps control gear shifts. If your 700R4 is stuck in first gear and will not upshift, you can access the governor through the governor housing cover on the transmission body.

Read more at:
http://www.ehow.com/how_8740017_remo...ing-700r4.html

Best of luck!

Larry

[68 TT]

Originally Posted by brycerowdy

Ok, so I drove the truck up and down the driveway on Saturday and the 396 was awesome. I need to get a tranny shift module put in so it will shift out of first gear. Other than that, the truck has been awesome.

It could just be the vacuum hose to the vacuum modulator on the transmission is leaking or fell off. Happens quite often.

Without that line connected and getting vacuum to the trans it will not shift out of first gear. Worth a look before you go buying parts.

[truckzilla]

Originally Posted by 68 TT

It could just be the vacuum hose to the vacuum modulator on the transmission is leaking or fell off. Happens quite often.

Without that line connected and getting vacuum to the trans it will not shift out of first gear. Worth a look before you go buying parts.

I wasn't aware that a 700R4 had a vacuum modulator.

[GMCJOE]

I would love for santa to get me a present like that. But for now, I will settle for buying my own parts. Hope that modulator does the trick for ya. Nice truck, looking forward to more pics.

[brycerowdy]

Ok I'll look tonight.
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[brycerowdy]

Larry it is a T400 trans

[truckzilla]

I'm sorry. Just ignore all that previous stuff then! A TH400 is a beefy trans! I had that behind my '88 crewcab Chevy dually with a 454. I couldn't break that trans if I had too! But it sure needed an overdrive gear something bad!

Maybe your problem is something as easily solved by checking your vacuum lines or maybe a funky modulator! Anyway, I hope you get it resolved so you can get it going good!

All the same, best of luck.

Larry

[White70C20]

I'm curious to see what RPMs you run with the th400 and 4.10 gears. My '70 C20 just seems to run kinda high rpms at 55-60 mph. I would like to put a 700r4 in it, but I also want to keep it as original as possible.
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[brycerowdy]

It will be a while till I put in the 700r4
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[brycerowdy]

[brycerowdy]

So as you can see i moved the truck outside for the winter to make room for my dads car. So for now there wont be many updates till spring time.

[truckzilla]

Not that you don't have anything to do in Colorado in the winter time!

When you're not out tearing up the slopes or jumping snowmachines, you can consider this to be planning and dreaming time!

[brycerowdy]

Oh, I didn't think of that! I guess it is time to get plans made up!