Noob Needs Help with TV/detent/mod/silinoid OH MY! '77 C-10 w/350 & 400

[devanray]

I have just purchased a '77 C-10 and am trying to get this safely on the road. My laundry list grows daily but I'll start off with my biggest concern.

She will shift from 1st to 2nd and then 3rd very fast and after that the RPMs just roar with little power. I have tracked this down to being tranny connection issue. Now, I've been told that I need a detent cable that will connect to the throttle bracket on my QuadJet, and others say that it an electrical switch that sits by the gas pedal some say adjust or get a new modulator. What should I do first??

When I figure out how to get pics on-line I will do that.

All right, any takers?

Any direction or help would be so appreciated. BTW, none of this is original, I saved this girl from a backyard (bailing wire and duct tape mechanic) he really didn't know what he was doing, sad to say, neither do I. But I plan on doing it right!

Thanks all!

[bake74]

     Vile I am sure or someone else will ask you more questions, but for now do a search in this section for " detent " and it will pull up 3 pages of previous post and you might get your answere, or at least know what kind of questions everyone is going to ask you.  Good luck and Welcome to the site from California.

[devanray]

Thanks!

I've been reading those posts and think I'm getting a bit closer to narrowing things down, but still am not sure if it's a cable to the carb or the wire to the transmission switch by the pedal that is supposed to be on this rig.

I'll figure it out either through these previous posts or this one, this site is fantastic for information and just plain nice folk.

Thanks again

[VileZambonie]

TH400 correct? There is no Detent cable. So your 1-2 shift is fine, 2-3 shift is early then slip correct?

You have checked the fluid with the engine running at operating temp right? What's the level and condition?

[three8six]

Yea but it could be something to do with the pedal switch that makes it down shift right?

[VileZambonie]

It's not the detent solenoid if that's what you're getting at.

[devanray]

The fluid is clean/spread evenly on a paper towel as it should, running ant normal temp in park, no high temp indications on the dipstick and the pan only had minor debris, very standard in my experience.

When the TH400 hits 3rd it seems to stay there, not slipping really, just hits it and the rmps go up, no tach so I can't give specifics. Also, when I shift (on the tree) it stays in N when I have it in D, the lever goes into the "indent" as it should but doesn't shift until I bring it into L2, than if I bring it back to D it stays in D (3rdgear), not sure if this means anything or not. Also, the linkage is loose, I'll check the shifting tomorrow, bought a Chilton manual so It should help a bit with making sure the shift linkage is doing as it is supposed to.

No detent cable, sweet, one thing off the list, It must be the pedal switch. I'll read up on the tranny switch and see what is needed, it hooks up to a solenoid right? And there is no modulator?

Thanks for your help, I've made it farther in the past few hours than I have in the past few days.

It's not the detent solenoid if that's what you're getting at.

This solenoid attaches to the transmission pedal switch right?

[slammed79]

The TH400 has a modulator, no selinoid that I am aware of.

[VileZambonie]

The 400 has a detent solenoid which is electronically controlled. It has a vacuum modulator and a governor valve. These all control shift points however if it's slipping in 3rd it's probably time for an overhaul.

[devanray]

Okay, got some pics and labeled them as best as I could with Vile's information.

The governor valve I have seen taken out of the tranny but can't figure out from where. What does it look like in the tranny? I'l read more on this unit to figure out what it connects to and such.

The 400 has a detent solenoid which is electronically controlled. It has a vacuum modulator and a governor valve. These all control shift points however if it's slipping in 3rd it's probably time for an overhaul.

The solenoid is electronically controlled by the transmission control switch, right? I would hate to think that the tranny is just shot, I'm willing to get everything hooked up as it should first and then see what happens. Should I not be driving this rig around until I get that control switch hooked up?

Am I learning anything or am I just walking backwards, eyes closed and chewing bubblegum? javascript:void(0);

Thanks again all!

[VileZambonie]

Your pix are correct, unfortunately the detent solenoid is for forced downshifts and would not be the problem. The modulator delays an upshift or forces a downshift based on engine load. The governor is road speed, the faster you go the higher the pressure. When governor pressure is higher than modulator pressure it forces an upshift. This is all control which doesn't sound like your problem if it's slipping in third.

Do you have access to a transmission oil pressure gauge?

[devanray]

  No, but I will see about renting/getting one. I'll get the results up for you as soon as I can.

Edit: I do actually have a oil pressure gauge but like most things on this truck, it isn't hooked up. I'm looking into the connections now.
How much should I expect a rebuild to cost? I know it varies depending on the parts needing to be replaced, but what should I expect, if I have to go this route and would it really be worth it? 
Thanks, I'll get the pressure reading as soon as I can.

[devanray]

Update:

So, getting the oil pressure may take some time, but today I had worked on the linkage and put in some new rubber tubing from the modulator steel tubbing to the intake (riser on carb). It seems to behave better than before, perhaps it is my imagination. The gear selector is still off and I will continue to work on that, still can't find a gas pedal transmission switch (not the cause but I want to see if it works and have everything hooked up properly before I spend big $$ on the tranny). Still seems to be at a high RPM in drive but the shifting seems to be spaced out farther as I would expect it to be.

I'll put new plugs in on Monday and tune her up a bit, just to make sure that it is 'all good under the hood'.

Would getting an RPM gauge assist with the diagnoses? Could you also describe to me what you mean by "slipping in third", just want to make sure we are on the same page. Also, is there some sort of 'koodos' button or someway to acknowledge your assistance with this Vile? Either way, thank you for your time and everyone else who has or will chime in. I'm doing my best to get around to other posts and see if I can help, but as of yet, my knowledge level isn't as high as most. If you have a question about a slant six in a '70 Duster, I'm your man!

Thanks again

[VileZambonie]

OK so now it sounds like you are just saying your RPM's are high in 3rd gear.... Let's hit the reset button here so we can get on the same page. Fix and adjust your sloppy linkage. AS far as the prindl gauge that's easy, just move the clip on the steering column jacket so it lines up correctly. The detent switch is here http://www.americanclassic.com/Google_Base_HTML_Pages/EL870NOS-1974.htm

If you manually shift 1st to 2nd, 2nd to 3rd do you have all forward gears with no slipping?

[devanray]

if you mean by 'slip' that it actually falls out of gear, back into second or high rpm and zero power, than no, it doesn't slip. Just high rpms but still stays in third with decent power.

Man, there it is, thanks for the link!!