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Old Jun 11, 2019 | 10:47 PM
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Default New c3 advice appreciated

New to me today after many years lurking..
79 4m tops l82 28400 miles.
Ok car sat for few years low mileage to begin with. Drove homeabout 5 miles noted coolant low bottle empty added half gallon seems to be holding. Previous owner didcalpers and tores.
Here is my advice list request please..
- clutch. Halftravels before engaging no slip but no play at top hearing bearing riding, is there an adjustment?
- ac compressor not engaging, shall iassume 134a changeover? Have vacuum pump and gauges, compatibility fixes? Oil etc?
- tach not working thoughts?
- door panel removal straightforward? Want to fix a few trim parts and the top of mirros loose like the shell rattles

Never had a corvette but familiar with general repairs, wow big furum, happy to be here finally...thank you.. i shall search all the forum but pointers appreciated.
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Old Jun 11, 2019 | 11:54 PM
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Clutch adjustment is easy. There's a rod under the brake caliper that connects to the clutch bell crank or Z bar. Loosen the outer nut a few turns and bring the Z bar out a bit, then tighten up the nut behind it. Check for 3/4" to 1" of play in the clutch pedal. Keep going outwards till you get that.

AC compressor, no idea, my '74 doesn't have one, but I recommend getting the FSM or Factory Service Manual as that has a ton of info on how to work on your C3.

Tach, mine is cable driven. They went to electrical or electronic one year or another, late in C3 production. Someone here will chime in and help out.

Door panel removal. The hard part is getting the clip out, from behind the inner door handle. After that, it's an OK job.
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Old Jun 12, 2019 | 06:45 AM
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Originally Posted by interpon
...pointers appreciated...
Order the 79 assembly instruction manual (AIM) and an owner's manual.
Congrats on the 79.
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Old Jun 12, 2019 | 07:33 AM
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Tach went electrical when the HEI came out in 75. So you have a electronic tach. Most likely the tach board is toast. It is on the back of the tach so you will need to remove the dash pad to access it. Make sure the Tach lead is on the HEI first to rule
out not being connected.
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Old Jun 12, 2019 | 08:44 AM
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Oops, already mentioned!

Last edited by Devs77; Jun 12, 2019 at 08:45 AM.
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Old Jun 12, 2019 | 01:21 PM
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Thank you all!!
i shall begin journey with the boy
in for oil change at dealer and inspection
why not
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Old Jun 12, 2019 | 02:36 PM
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Ordering manual
dealer wants to review clutch thinking needs replacement but not sure
says adjustment not the issue
Says not throw out bearing although I thought I heard and can stop noise by depressed clutch
doesnt seem to slip? Do they wear that way?
opinions?
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Old Jun 13, 2019 | 01:28 PM
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Dealer says no clutch adjustment on my 79? Is he wrong? Says clutch bad, i cannot see how i would lose free play at top of clutch by wearing?
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Old Jun 13, 2019 | 02:25 PM
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Originally Posted by interpon
Dealer says no clutch adjustment on my 79? Is he wrong? Says clutch bad, i cannot see how i would lose free play at top of clutch by wearing?
Free play at the top of the clutch pedal is determined by just how I told you to do it, earlier in this post. Open the hood. Look under the brake booster on the driver. There is a long rod sticking out of the firewall, with two 9/16 bolts sandwiching a square metal piece. Loosen the outer 9/16 a 1/4" to 1/2"and move the upper crank arm towards the front of the car. Tighten the rear 9/16 nut behind it and then tighten the front 9/16 rod. Check the pedal play. If not enough, repeat the process. If too loose, move the crank arm back.

I've done this numerous times, it's easy to do.

Last edited by F22; Jun 13, 2019 at 02:26 PM.
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Old Jun 13, 2019 | 02:42 PM
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Old Jun 13, 2019 | 02:45 PM
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Originally Posted by F22
I shall print and bring it with me.. I really lost faith in these guys.... thinking in my head WTF? if not hydraulic clutch it HAS TO ADJUST they say the rod is not threaded.. I said look again will pick up today regardless.. BTW estimate for clutch..1700... sounds like some higher jack stands in future if I need to do clutch...and thank you for your reply

Last edited by interpon; Jun 13, 2019 at 02:48 PM.
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Old Jun 13, 2019 | 02:56 PM
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Originally Posted by interpon
I shall print and bring it with me.. I really lost faith in these guys.... thinking in my head WTF? if not hydraulic clutch it HAS TO ADJUST they say the rod is not threaded.. I said look again will pick up today regardless.. BTW estimate for clutch..1700... sounds like some higher jack stands in future if I need to do clutch...and thank you for your reply
There is no hydraulic clutch in a C3 stick shift four speed Corvette. As far as I know, all of them were mechanical linkages from your foot to the throw out bearing. The rod is threaded! Unless somebody swapped out your transmission for a five or six speed, then you might have a hydraulic clutch set up. And $1,700 is pretty friggin' steep to do a clutch. $300 clutch, $1,400 labor for one afternoon's work? Wow. I'd be bringing it to a different shop.
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Old Jun 13, 2019 | 06:05 PM
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You might try a different garage. The rod is threaded, as shown in the photo @F22 posted. The procedure is also called out in the shop manual, which you should pick up. Bring a copy into your new shop.

If, like mine was, you are OUT of adjustment, you may need to rebuild your z-bar. Can you post a photo?

Congrats on the 79 4-speed! You have the best parts of my two cars.

Last edited by Bikespace; Jun 13, 2019 at 06:07 PM.
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Old Jun 13, 2019 | 06:38 PM
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Car at dealer for an oil change? You screwed up already! Cmon man
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Old Jun 13, 2019 | 07:52 PM
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Lol..oh i do my own maintenance, this was a chance for me to go to a dealer who also claims corvette knowledge including older, get every detail looked at on a hoist in detail which i am willing to pay for once. I also got to spend timewith mechanicand review everything.
so apparently there was a miscommunication with advisor and mechanic, he said he did adjust and drive it and inspect everything. He stated he can here the throwout bearing and clutch needs to be replaced and notsure if someone adjusted wrong as third to second is sometimes difficult...bottom line i paid got confirmation that indeed it appeared to be a 28000 mile car and well taken care of and i have free play and drives very good with clutch adjusted. He stated there is not much thread left to adjust and needs replacement.

so as i pull away from my 1999 last oil change 400 miles ago in twenty years as sticker was still on windshield...the horn goes off like an alarm!! Lol it had an alarmfrom 1980 that apparently decided to go off...and not stop..drove back they tried cutting a couple wires basically i finally unplugged the horn...

well do i start a threadfor advice new or can i add it here for alarm. I have contributed to honda ridgeline forum for years and the value of these forums and everyones help

here is threaded clutch.lookslike i may have some life left?
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Old Jun 13, 2019 | 08:01 PM
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Default 1980 alarm removal advice please

So horn unplugged.
i have an old alarm thatdecided to go off..
i can see
- toggle swtch under dash
- toggle switch in carpet by right driver calf area
- switch under hood
- an apparent siren?
- an led in side fender by emblem for alram i thought was for horn...it wasn’t
- i think i see why my tach don’t work
- a wiring mess

let’s start slow...is this siren andflasher looking thing need to completely go away? I will temporarily tape where the used split crimper areas are and try to find some goop? Recommendations?



ok so i am as
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Old Jun 13, 2019 | 08:04 PM
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And is this hole with wires going under dash supposed to be there and if so ( i assume some are factory) which stay?
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Old Jun 13, 2019 | 08:07 PM
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And then this switch..i assume one switch wire is ground and one jammed into harness i will remove.
also is that ground cable supposed to be on valve cover bolt? If so where does it go?
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Old Jun 13, 2019 | 08:11 PM
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And please tell me whats going on with my tachometer wires and filter..looks butchered too. Tach dont work..its on the list and key on doesn’t do anything not on 0
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Old Jun 13, 2019 | 08:12 PM
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You may have some life left. Try the adjustment out and see how much play you get in the pedal. 3-2 shift problems have nothing to do with the clutch, so much as the adjusting the shifter rods. You have to align all three. See this thread:

https://www.corvetteforum.com/forums...se-jammed.html

As far as electrical, you're going to need at the minimum, the Factory Service manual for your year C3 and a good aftermarket wiring diagram (the kind that are printed on laminated paper, are huge and have colored lines for all the wires). You should have some experience or be willing to learn multimeter use and if you're going to really get into it, a Power Probe III electrical diagnostic tool and a willingness to learn basic circuitry and how it applies to cars. You definitely have after-the-fact wiring and you're either going to have to run it all down yourself, or pay someone to do it (not exactly the cheap way to go).
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