Graham's Corvette Blog and Studebaker bits 'n' bobs

All dash lights replaced by LED units and working. The brake warning light is still an incandescent bulb as I couldn’t tell which side was ground to test it on the printed circuit board. It’s bright enough and is not used for long periods.

The new tach board and filter works, but the extreme graphite I used on the speedometer cable didn’t. the needle is more jumpy than ever!

The old tach filter registered 30 ohms where it should have been only 15. It may have been the problem. I’ll save the old tach board to use should the new board fail. I understand that some boards are made in China and are not reliable.

Before I replaced the clear plastic instrument cover I gave it a cleaning with Novus plastic fine scratch remover. It also cleaned out the fogging. I have also used it on modern car headlights to keep them bright.

I replaced the missing parts for the horn in the steering column and installed the new horn I got from Corvette Depot. It works fine, but I’m a bit disappointed as it is a universal brand with an adjustable flat mounting bar. It still fits OK. I would have liked an original style with the correct ‘L’ shaped bracket.

I installed a new headlight overriding valve that sits under the middle of the lower dash on the drivers side. The old one was broken off and I suspect that it was hit by the driver’s leg getting in or out of the car. I almost did it too so I cut it back so just enough of the pull arm was left to do the job. Hopefully I won’t knock it off. If I do I’ll have to buy a new switch and mount it elsewhere.

Next I’ll re-lubricate the speedometer cable and go back to the alignment shop for the 4th time. It still wants to head right and it doesn’t want to return to centre on right turns.

I removed the anti-theft horn. I tested it and it has 9.6 ohms resistance. Checking with the Google teck it seems horns should only have 1 ohm of resistance.

At some point on my test drive one of the anti-theft sensors must have failed and grounded out. This triggered the anti-theft relay which in turn connected the horn to ground via the anti-theft flasher. The service manual shows that the circuit from the battery is through the horn then the flasher, then the relay and then ground. A 20 amp fuse is between the battery and the horn. So I am fairly comfortable that the heavy draw through the horn caused the courtesy lights to flash and the fuse to heat up and finally blow. When I ran the test the fuse got hot to touch after only a matter of seconds.

I just got an email that Corvette Depot have mailed my second horn, ignition switch, lock and door set, and hot water shutoff valve.

Now it’s time to get the dash back together, test the tach, get the horn working and get the console covered and the seat back in place.

Easier to remove the console side panels and work under the dash with the seat out. Easy-peasy with only four bolts to remove.

The short caused the courtesy lights to flash through the anti-theft flasher and then burn out the fuse. I removed the flasher and the anti-theft relay under the console. With them removed the problem was bypassed and the courtesy lights worked without burning out the fuse. Still don’t know where the shorting problem lies.

I used shrink-wrap to isolate all the anti-theft relay leads. I plan to remove all the anti-theft components, but leave the wiring in place.

Dash removal wasn’t too difficult. It was easier with the steering wheel off and would have been even easier if I could have lowered the steering column, but it didn’t want to lower when I loosened the dash mounting bolts.

I need to replace the tach circuit board so it was also a good time to replace all the dash light – some weren’t working – with new LED bulbs. I tested the led bulbs and they do dim with a reduction in voltage. A bit tricky putting them in the dash since they only work one way being diodes. I had to run 12 volts through each bulb’s circuit to be sure they lit properly.

The new tach circuit board comes with three insulating washers, but no instructions on where to use them. I’m assuming on the metal back of the tach to isolate the circuit board – the new board’s contact points are on both sides of the board.

Dash out and easier to get at the headlight and wiper switchs for testing.

Switches out and now the testing can begin to find why the dash lights aren’t working. I don’t think the short is in the dash light circuit as the anti-theft horn relay, etc are all under the courtesy light fuse.

With the dash out it’s a good time to give the speedometer cable a good coating of graphite. The needle had been a bit bouncy.

I tried cleaning around the hood latches, but it just wasn’t working so I opted to remove the latches being careful to mark the edges so that they would go back in the exact same spots.

With the latches out it was much easier to clean. Notice the body plug just left of center at the top. This I believe is how you get the hood up should the hood cables fail. There is a plug on both sides. On the passenger side a screwdriver would be used to lift the latch trip lever and on the opposite side the driver would be used to press down on the latch trip lever. I’ve left the bits of gasket type stuff around a couple of studs to help locate the latch in the exact original position. On the other side I used a dental pick to scribe lines on two edges for the same purpose.

Everything cleaned up and a spray of white grease on all the moving parts of the latches.

The old cable was still working, but it was beginning to fray.

New cables in place and working well. I’ve also brushed on heavy rust check on the nuts and bare metal. May get to paint them later on.

Next: a dreaded electrical short.

Just a quick recap on the valve cover leakage. The cover on the passenger side was leaking badly a the back bottom corner where the oil gathers before draining back down the block to the pan. It was getting on the exhaust pipe, smelling bad and leaving a trail of blue behind the car. On the advice of a local mechanic (Chevy MacDonald!) who is a Chev racer too, I bought a set of 3/16″ composite FelPro cork gaskets.

I have coated both sides of the gasket with anti-seize paste. That way the gasket will come away from the block and the cover without breaking if I have to remove the cover for any reason. The old gasket was a rubber compound and should have worked fine, but…

I use two small removable studs on the lower side to hold the gasket in place and then align the valve cover.

I only use a 1/4″ drive extension with a driver handle to install the valve cover nuts. That way I won’t over-tighten the bolts. I’m also using spreaders under the bolts to distribute the pressure along the cover lip.

Success! Only the lightest misting of oil at the back of the valve cover. After letting the engine cool I again snugged down the bolts again – not as tight as I could, just a bit now that the gaskets are warm and there is some looseness.

Next some parts arrived and I can replace the hood release cross-engine cable.

Painted brackets in place with a new tie-down bolt. I took the opportunity to spray heavy Rust Check fluid on all the surface rust I could see.

Cleaned out years of crud in the well.

New used tire in the well. That’s a 205/70 R15. There’s lots of room in the well so I’m thinking I’ll look for a used 225/70 R15 that will match the tires on the car.

All neatly tucked away – hopefully will never see the light of day!

Next I’ll need to stop a bad valve cover oil leak before I take it for a 100 km trip to the windshield shop.

Back from the alignment shop. They did both front and rear. Took them three tries to get it right so that with the steering wheel centred it would go straight and not veer to the left. Hard to get it right with these old steering boxes.

Borrowed this too from a friend. Better than trying to line them up in the garage or going out at night to some level spot with 20′ of so to a clear wall. I couldn’t think of any spot locally that would do.

First I disconnected the vacuum hoses to the headlight actuators.

That allowed me to manually raise the headlights. They can be pushed up from under the lower grille.

I removed the headlight surrounds to give better access to the adjusting screws. Three of the screws had stripped the plastic mounts – poor setup! I managed to get a fitting on the screw where it extends behind the plastic mount.

First thing is to measure the slope of the floor with this transit device. The dial at the top has level at 0 and plus and minus sides. With it on the floor you look down an opening in the device at a split mirror. The screw on the bottom is used to align the marks so that they are in a straight line. Then you turn the dial on the side until the bubble level in the top sits in the centre.

The plus or minus number reading from the transit is then used to set both headlight aimers. This is the left. The verticle lines are viewed through a split mirrorin the aimer on the other side.

With the aimers in place the headlight screws are adjusted to get the correct readings on the aimers.

The side to side is correct when the alignment bars line up in the view hole (between the two gauges). The up and down is correct when the bubble gauge (far left) in centred. If you can’t get things to line up properly you can use the white buttons to get things lined up. The readings from the white buttons tell you whether the final adjustments are in tolerance. If not then you need to make modifications to the headlight mounts to get it correct or within tolerance.

Final job it to re-attach the vacuum hoses to the actuators.

Headlight surrounds back in place. The headlights will have to stay up until I next start the engine. The Service Manual give directions to manually raise the lights and states clearly that they must not be pushed down. Once the car starts the vacuum system will do it’s thing and they lower.

The hub caps are not too nice with lots of pits and the trim rings have some curb rash. Still they are presentable enough and worth a shine up before putting them back on the car – after I get the alignment done.

Starting to work on the AC. Rewired the connections and added an adapter on the low pressure side for the newer refrigerants.

The AC throttle ‘kicker’ is toast so I’ll need to order a new one of those.

Time to prep for the windshield replacement. All the attaching screws of the surrounding windshield trim need to be loosened so that the job doesn’t get held up because the tech has broken off a screw or can’t get it out.

Some screws had to have a slot cut into them with a dremel tool with a small cutoff wheel.

That worked in one case, but the other thee stuck screws had to be coaxed to turn with a fine chisel and hammer and then removed with a small vice grip.

Got all eight out and then replaced the trim with new screws. I still need to check the large stainless T trim piece.

Time to go to the alignment shop. Hopefully the suspension is up to snuff!

First step to checking the timing is to remove the dist cap so movement of the rotor can be seen.

Next I rolled the engine over until the timing mark on the harmonic balancer is in view.

Next I rotated the engine one way until the rotor just moved. The mark is at the 8 degree BTDC mark.

I then rotated the engine back until the rotor just moved. The mark now rests at the 4 degree mark ATDC. So a total movement of 12 degrees.

Not good. From what I have read 4 or 5 degrees is normal wear. In a pinch up to 10 degrees might be OK if the engine is running smooth. 12 degrees is just too much. At idle my timing chain is flopping about and causing valves to open and close at the wrong time – thus the very rough idle. Once the engine is above 900 rpm or so it smooths out as the torque of the engine is keeping the timing chain taught. That explains why all my plugs are firing OK.

I will continue to drive the car this summer as is. I don’t plan any long trips. All I really need to do is have the alignment done, a new windshield installed and then a safety check so I can get it plated.

My project for next winter was an overhaul of the PS pump, control valve and piston. I need to replace the PS pump bracket so I’ll do all that when I install a new timing chain and gears.

The spare tire rim is in good shape. Just lots of surface rust. I won’t bother to have it sandblasted. It will likely not see the light of day!

My quest to find the miss-at-idle continues. I have replaced the coil, put in new wires and rotor, and now a new cap.

Installed, but as expected the miss is still there. Before I install a new condenser and electronic module I am going to check the timing chain for sloppiness. I had rough idle problems with my Dodge 360. Turned out to be a worn timing chain.