'73 Distributor Question
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
'73 Distributor Question
I bought this car with no distributor in the engine. No explanation as to where or why it was missing.
I understand that this year's model has it's tachometer operate via a flex drive cable attached to a particular type of distributor that has the flex cable drive attachment on it.
I looked underneath the dash, trying to find any cable emanating from the back of the tach. It's a jungle down there and I cannot find it. I found the speedo cable, and see where it threads out through the firewall, but no tach drive cable anywhere.
My question is: Where does the tachometer cable supposed to go through the firewall and to the distributor?
Perhaps it's missing too. Maybe the PO sold the distributor and cable together.
Any input will be appreciated. Thanks.
Steve
I understand that this year's model has it's tachometer operate via a flex drive cable attached to a particular type of distributor that has the flex cable drive attachment on it.
I looked underneath the dash, trying to find any cable emanating from the back of the tach. It's a jungle down there and I cannot find it. I found the speedo cable, and see where it threads out through the firewall, but no tach drive cable anywhere.
My question is: Where does the tachometer cable supposed to go through the firewall and to the distributor?
Perhaps it's missing too. Maybe the PO sold the distributor and cable together.
Any input will be appreciated. Thanks.
Steve
Burning Brakes
Joined: Aug 2004
Posts: 802
Likes: 1
The 73 has a mechanical tach.
First check to make sure the original tach is still there. Maybe someone converted to an electronic tach.
The tach cable does go thru the firewall as well as the speedo cable. Maybe someone has a pix of it.
If your replacing the mechanical tach, you will need the cable and the tach. Distributers with mechanical drives are available new. Distributers with proper numbers are hard to find.
Also check the tranny. The original 73 had a right angle adapter from the tranny to the cable for a manual tranny. These adapters are impossible to find, but straight adapters are available from many vendors. The original right angle adapters tended to seize up after a few years causing the plastic drive gear inside to shear.
You will also need the plastic drive gear that comes in different colors depending on the rear end ratio. You'll need to figure this out.
Steve L
73 coupe since new.
First check to make sure the original tach is still there. Maybe someone converted to an electronic tach.
The tach cable does go thru the firewall as well as the speedo cable. Maybe someone has a pix of it.
If your replacing the mechanical tach, you will need the cable and the tach. Distributers with mechanical drives are available new. Distributers with proper numbers are hard to find.
Also check the tranny. The original 73 had a right angle adapter from the tranny to the cable for a manual tranny. These adapters are impossible to find, but straight adapters are available from many vendors. The original right angle adapters tended to seize up after a few years causing the plastic drive gear inside to shear.
You will also need the plastic drive gear that comes in different colors depending on the rear end ratio. You'll need to figure this out.
Steve L
73 coupe since new.
Burning Brakes
Joined: Mar 2013
Posts: 1,018
Likes: 581
From: West Monroe Louisiana
2023 C3 of the Year Finalist - Unmodified
You can see the tach cable below the vacuum line and above the orange line. This is on my 73.
Here is what the distributor looks like.
http://forums.corvetteforum.com/c3-p...stributor.html
Donnie
Here is what the distributor looks like.
http://forums.corvetteforum.com/c3-p...stributor.html
Donnie
Last edited by DonnieP73; Nov 28, 2013 at 01:23 PM. Reason: add information
Melting Slicks
Joined: Oct 2007
Posts: 2,310
Likes: 9
From: KB7TIF Ville NV
I bought this car with no distributor in the engine. No explanation as to where or why it was missing.
I understand that this year's model has it's tachometer operate via a flex drive cable attached to a particular type of distributor that has the flex cable drive attachment on it.
I looked underneath the dash, trying to find any cable emanating from the back of the tach. It's a jungle down there and I cannot find it. I found the speedo cable, and see where it threads out through the firewall, but no tach drive cable anywhere.
My question is: Where does the tachometer cable supposed to go through the firewall and to the distributor?
Perhaps it's missing too. Maybe the PO sold the distributor and cable together.
Any input will be appreciated. Thanks.
Steve
I understand that this year's model has it's tachometer operate via a flex drive cable attached to a particular type of distributor that has the flex cable drive attachment on it.
I looked underneath the dash, trying to find any cable emanating from the back of the tach. It's a jungle down there and I cannot find it. I found the speedo cable, and see where it threads out through the firewall, but no tach drive cable anywhere.
My question is: Where does the tachometer cable supposed to go through the firewall and to the distributor?
Perhaps it's missing too. Maybe the PO sold the distributor and cable together.
Any input will be appreciated. Thanks.
Steve
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
That's what first crossed my mind when I couldn't find a tach cable.
The tach's face looks stock. It's just an absolute bitch to get up there behind it. The steering column bracket is huge and covers up a lot, and the center A/C duct doesn't help matters either. I DO want to see what that guage looks like from the back. But how? I'll guess some of that stuff has to come out.
Wonderful.
Thanks for the replies folks. I'm very new to this car, but learning fast.
Steve
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Also check the tranny. The original 73 had a right angle adapter from the tranny to the cable for a manual tranny. These adapters are impossible to find, but straight adapters are available from many vendors. The original right angle adapters tended to seize up after a few years causing the plastic drive gear inside to shear.
Burning Brakes
Joined: Aug 2004
Posts: 802
Likes: 1
Steve L
73 coupe since new
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Burning Brakes
Joined: Aug 2004
Posts: 802
Likes: 1
So this explains why I can't find a replacement. Does your 73 have this right angle adapter?
I was looking at taking my original apart but it has two welch plugs that need to be removed to get at the innards which makes it a pain. Meantime, to plug up the hole in the tranny, I was going to get an aftermarket straight but now I won't bother.
I didn't realize that the cable also plugs straight into the straight piece until I just looked at mine. Should have noticed this before, it's obvious now that I look at it.
Steve L
73 coupe since new
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,595
Likes: 7,043
From: New Or-leens Loo-z-anna
Steve,
That's what first crossed my mind when I couldn't find a tach cable.
The tach's face looks stock. It's just an absolute bitch to get up there behind it. The steering column bracket is huge and covers up a lot, and the center A/C duct doesn't help matters either. I DO want to see what that guage looks like from the back. But how? I'll guess some of that stuff has to come out.
Wonderful.
Thanks for the replies folks. I'm very new to this car, but learning fast.
Steve
That's what first crossed my mind when I couldn't find a tach cable.
The tach's face looks stock. It's just an absolute bitch to get up there behind it. The steering column bracket is huge and covers up a lot, and the center A/C duct doesn't help matters either. I DO want to see what that guage looks like from the back. But how? I'll guess some of that stuff has to come out.
Wonderful.
Thanks for the replies folks. I'm very new to this car, but learning fast.
Steve
Can you get a rectangular mechanic's mirror behind the dash with a bright drop-light to see the back of the tach.......that would save you a LOT of time and Advil!
Is it is an original WORKING TACH----you need to verify that it works before spending un-necessary money on a tach-distributor.
(My "new" '68 project had a tach-drive dist. when it was new---I bought a moderately priced aftermarket HEI tach-drive dist. and cable because the original mechanical tach still works---and the car has been altered too much to do a full restoration, since I don't have $60,000 to spare....LOL)
Last edited by doorgunner; Nov 28, 2013 at 07:46 PM.
Burning Brakes
Joined: Aug 2004
Posts: 802
Likes: 1
Many yrs ago, either my tach or speedo died. I was able to replace it by just taking out the screws on the instrument panel and pulling back the instrument panel. You may be able to do this enough to get a look at the back end of the tach. or at least get a hand in from the top to feel the back end of the tach. You might have to take off the lower trim piece under the steering wheel. There is nothing else holding the instrument panel in place except these trim screws that you see from sitting in the drivers seat. This shouldn't take more than 15 minutes and you don't have to go from underneath.
The mechanical tach has a leaf spring arrangement dead center of the tach. You push down on the lower side and the cable releases. You should be able to feel this spring for a mechanical tach even if the cable is not there. The spring is captured on the tach itself. There are also a couple of light bulbs with wires so don't confuse these with electric tach wires. I don't have a pix of the back end but someone might be able to post one up.
Steve L
73 coupe since new
The mechanical tach has a leaf spring arrangement dead center of the tach. You push down on the lower side and the cable releases. You should be able to feel this spring for a mechanical tach even if the cable is not there. The spring is captured on the tach itself. There are also a couple of light bulbs with wires so don't confuse these with electric tach wires. I don't have a pix of the back end but someone might be able to post one up.
Steve L
73 coupe since new
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Can you get a rectangular mechanic's mirror behind the dash with a bright drop-light to see the back of the tach.......that would save you a LOT of time and Advil!
Is it is an original WORKING TACH----you need to verify that it works before spending un-necessary money on a tach-distributor.
(My "new" '68 project had a tach-drive dist. when it was new---I bought a moderately priced aftermarket HEI tach-drive dist. and cable because the original mechanical tach still works---and the car has been altered too much to do a full restoration, since I don't have $60,000 to spare....LOL)
Is it is an original WORKING TACH----you need to verify that it works before spending un-necessary money on a tach-distributor.
(My "new" '68 project had a tach-drive dist. when it was new---I bought a moderately priced aftermarket HEI tach-drive dist. and cable because the original mechanical tach still works---and the car has been altered too much to do a full restoration, since I don't have $60,000 to spare....LOL)
If mechanical, he will still need a cable to test it with a drill attached. If it works then it is a decision point as to whether to go as you did with the HEI hybrid unit get a true tach drive distributor.
Thread Starter
Melting Slicks
Joined: Oct 2013
Posts: 2,569
Likes: 126
From: San Diego California
Paul: Thanks for the Picture. Here's mine:
Just an oil pressure line & a few wires. I can borrow a borescope from work. Good idea.
Doorgunner: Good idea on the mirror. Got one on a stick at work too.
Thanks for the ideas guys!
I do now have a strong suspecsion the PO sold both distributor and cable.
Steve
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Nice photo reference. Good to have but not critical:
Last edited by Easy Mike; Nov 29, 2013 at 09:48 AM.
Burning Brakes
Joined: Aug 2004
Posts: 802
Likes: 1
If you have the tach out, you don't need a cable to check the operation. Get a #2 Robinson drill bit-that's the square one. Put that into the drill chuck and run it in reverse.
Ya I know, USA doesn't typically use Robinson, although it is much superior than Phillips cause it never strips a screw, also holds a screw on the bit in mid air so you can free up a hand. But these bits are usually in the multi bit packages.
Steve L
73 coupe since new
Ya I know, USA doesn't typically use Robinson, although it is much superior than Phillips cause it never strips a screw, also holds a screw on the bit in mid air so you can free up a hand. But these bits are usually in the multi bit packages.
Steve L
73 coupe since new
Racer
Joined: Oct 2013
Posts: 254
Likes: 3
From: Tampa Bay Florida
Easiest, although maybe not the fastest access to the back side of the tach is removal of the tach/speedo cluster from the passenger compartment side. Much easier on the neck and back! I'm amazed that you were actually able to contort yourself up under the dash. Rebuilt points-style and aftermarket distributors are available thru Corvette America and Corvette Central. '75 and later Vettes have HEI distributors with no mechanical tach drive - they're all electronic and your car may have a later model transplanted into it. HEI distributors are far more plentiful than mechanical tach Corvette distributors. You came to the right place for advice. CF has helped me several times. Good luck.
Last edited by pacecar620; Nov 29, 2013 at 01:26 PM. Reason: add'linfo