Graham’s Corvette Blog and Studebaker bits ‘n’ bobs

Upper bolts come out easier if the weight is taken off them by jacking up the suspension. The rear shocks actually hold up the suspension when the car is on the hoist.

The lower mount is held together with a wide fine thread nut, a cupped washer and a lock washer( missing from one side). I assembled the lower mount and ended up installing the cupped washer the wrong way. The cup faces outward for some reason.

It was a 50/50 guess as to which end to mount first. I chose the lower – wrong! With these shocks it is almost impossible to get the upper mounting bolt through the frame mount with the lower end mounted. Once the upper bolt is in place the shock can be twisted to fit onto the lower mounting pin. All in place now and top and bottoms torqued to spec

An interesting tid-bit in the service manual is a procedure to get the oil properly re-located after the shocks have been sitting flat for a period of time. It recommends that each shock be stretched and compressed five times. I don’t know how long the shocks have lain flat so I opted to do it.

Front shocks out. One had no resistance either way and the other a bit only one way. Got the sense that these might be the originals that came with the car.

Often the most difficult part to remove is the upper front nuts as you need to hold the shock rod with vice grips to stop it from turning. If the nut is too corroded it is hard to get a good enough grip on the rod to remove the nuts. If that doesn’t work then a nut splitter or cutting torches are needed. Fortunately these came off relatively easily. I had sprayed them a couple of times over the last couple of weeks with penetrating oil and it seems to have helped.

The bottom screws were well lubricated with engine and leaked shock oil. They came off easily.

Lots of shocks available for this car. Many of them are performance units and the price is sky high – like $500+! I’ve opted for basic original equipment replacements from Monroe. A much more reasonable price $282 taxes in from a local parts supplier.

New front shocks in place. I’ve only wiped off the shock mounting surface. Proper cleaning and painting will happen when I tear down the front end and replace all the bushings and maybe new springs.

The service manual calls for 150 inch pounds of torque. Didn’t seem like much, but when I tried it after with a regular wrench they seemed tight enough. Still I used some blue lock-tight to be sure.

Now onto the rear shocks.

The Corvette actually has a working light under the rear bumper to show the spare tire at night. Good idea. I’ve replaced the bulb with an led unit. I cleaned the crud from the bulb housing and it now shines nicely

Normally this car’s rear lighting for park and brake only work on the outer lights. I wanted to have all 4 working. I worked over the wiring and installed two red 1156 Led bulbs in the inner lights. Now I have 4 lights for braking and turn signals. I’ll replace the inner sockets with 1157 units later so that I also have 4 parking lights as well. That will mean some rewiring.

I also tried to tie in the backup lights so that I would have 4 brake lights shining for reverse. No luck. I am getting back feed and all four lights flash with the turn signal. Not a problem. I’m going to install two diodes on the backup light feeds so I will get 4 bright red lights for backing up. Should be passable and I get to keep the original lens look 🙂

Picked up a nice set of yellow driving lights on Amazon. Same as the ones I fitted to my ’74 Dodge truck. Really nice and bright. I want to install them behind the front grilles to the inside of the parking lights. They will fit, but they can’t be turned to face directly ahead. I’d have to make a special bracket. Rather than do that I returned them and ordered a smaller set that (only 3″ across instead of the 5″ or so) should be manoeuvrable.

The bearing on the AC compressor sounds a bit loud, but I decided to give it a try. I started the engine and filled the system with 12A gas. Sadly no cold air coming out of the vents. I checked the service manual AC checks and it appears that the evaporation tube orifice may be blocked. The next day I took the car out for a drive hoping that the system might clear itself and get going with the pump running at driving speeds. Unfortunately the system had leaked down enough that the pump quit. I may try recharging the systems and adding a can of stop-leak they taking if for a drive.

The final option – for next winter – will be to buy the R134a conversion kit from Corvette Depot and doing a full overhaul of the system. Might be the best bet anyway.

Meanwhile I have parts on the way and lots of little things to look at before the end of the driving season.

Time to wire up for a set of driving lights. Easier to work with the seat out. I’m also going to install a new ignition lock. My plan was to tap into the radio power lead for the driving lights as the power would be on only with the key in the ON or ACCESSORY position.

After thinking about it for a bit I thought I’d try to use the optional accessory electric fan circuit, but that didn’t pan out. Just above it was a free fuse connection. I tested it out and one side had power only when the key was in the ON position – that’s even better. I soldered up a spade connector to one side of an inline fuse (see the white wire going into the fuse panel about the centre of the picture. I’m using a 15 amp old style fuse.

Next I squeezed the #14 wire (soldered to the inline fuse) beside the speedometer cable firewall grommet and out into the engine compartment. I then tucked it into the existing harness cover going to the headlights and left a coil of wire under the front for the new lights. Got an email today that I’ll be getting the driving lights are being delivered – picket them up on Amazon.

Unfortunately the ignition lock I bought from Corvette Depot wasn’t right for my ’79 model. It didn’t have a groove on the underside to accept a locking screw. They are taking back the unit for a store credit – I could have had a refund – and I’ll order a new set.

Nice new heater valve with bracket. The illustration manual shows a heater valve, but without a mounting bracket. It is simply fitted in the small heater hose and left to hang there and bang around.

The best place to mount it is where the old heater hose bracket was located.

Fortunately the bracket was held on with aluminum rivits so was easy to remove and cut flush with the inner fender.

To get it mounted on the flat part of the inner fender I had to drill an extra hole just to the left of centre on the bracket. I also enlarged the holes to take 1/4″ stainless bolts. I’m using the large body washers to provide extra support on the outside of the inner fender.

Drilling the holes was easy, but I also had to shave the heater valve bracket to fit by the raised sections of the inner fender that were used to mount the heater hose bracket.

Valve mounted and secued through the fiberglass inner fender with the large body washers. First chance I get I’ll spray them with rock guard to keep the washers from rusting. The bolts and nuts are stainless and I used shake-proof galvanized locks.

All nicely in place and working fine. The location will make it a little more of a pain to get at plugs 2 & 4 – if I had put it where the illustration manual indicates, it would have been in the way of plugs 6 & 8 so no real loss or gain.

Next: time for more inside work.

One of the trans cooling lines rusted bad enough to start leaking. So I replaced two sections with rubber hose until I buy a new set of lines. I added a bit too much oil to the trans thinking I lost more oil than I did. So it had to go or the oil might start to foam in the trans. I’m using a brake bleeder setup to extract the extra oil.

I used the vacuum pump to suck out the extra oil. Worked a charm. I took enough out so that I would need to add oil when the trans was up to temperature. Which I did.

My old hood release cable that runs across the firewall had begun to fray (the outer cover) so I bought a new cable from a Corvette supplier. It fitted OK, but it kept stretching and would only release the left side. I had to reach under the hood to grab the cable and pull it until the right side popped. I then had to re-adjust it. After doing this four times or so the bracket on the left broke. The cable core also pulled out. When I released the cable tab on the right side it broke off. Seems the tab plastic is too brittle and breaks easily. Also, the cable stretches.

I wrapped up the old cable with dry vinyl (I don’t use regular electrical tape unless I have to since in a short time the glue turns to goop if it gets heated at all!). The old tabs are fine and the cable seems OK. Put it back on the car using the original adjustment hole and it is working perfectly.

Hoist up full height for this job. Good for working underneath, but the hood hits the ceiling so no engine access from the top.

Borrowed this socket from a friend who has an awesome tool collection. There just isn’t enough room to use a 5/8″ wrench without removing the spare tire and the whole spare tire assembly from under the rear.

Definitely a tight spot to get at.

A selection of tools to take with me under the car. In the end it came off with just the socket long extension and the ratchet.

The leaking rear shocks are pretty obvious. Same for the front so I expect that is why the car gets a bit ‘squirrelly’ when going over bumpy spots like railway crossings and rough bridge sections.

Using this ‘sucker’ I was able to get out about 1.5 quarts of oil from the differential.

I used this slender bottle with a squirt top to get the fluid into the diff. I put 4 oz of limited slip additive into about a pint of 80/90 hypoid gear oil and put that in first. after I was able to get another quart or so of oil before it began to overflow.

The oil from the diff was very black compared to the new oil colour (upper left).

Job done, but there is still about a pint of old oil in the diff. I’ll run it for the rest of the summer and then change it again. That should get rid of most of the old oil.

After a repair to the trans cooler lines (actually rusted through and began to spew oil everywhere!) I took the Chevy for a test drive and the chatter on sharp corners is gone 🙂

The extreme graphite spray didn’t work so I decided to try white lithium grease. First a spray to get inside the coils and then a liberal smear of grease on the outside. When re-installing the cable I ran it back and forth and spun it around. I noticed it grabbing a bit when I was spinning it. So that may be the problem – a bad casing. Underneath I pulled the cable casing back towards the trans giving it a bigger arc as it curved into the trans case. If this doesn’t work I’ll replace the cable and case as a unit. Maybe over the winter.

The window washer isn’t working. Time to pull it. The washer bottle is hidden beneath the left fender. It is in two parts – a neck and the main bottle. A bit of a bear to get at the mounting screws. I removed the neck and was able to twist the bottle around so I could get at the motor and electrical connection. There is no room between the fender top and the power brake unit to get the bottle out and I don’t want to remove the master cylinder and possibly damage a brake line moving it out of the way.

The little pump motor was seized. I pulled it apart and was able to clean up the motor, but it really didn’t want to work all that well. I can get a new unit from Car Quest for about $20 so a no brainer!

Time to open up the door again and adjust the window so it meets the rubber at the top and back of the body. I needed it to go up and back about a 1/4″, but no luck. The motor spins free before it reaches the top. Seems the plastic gears are stripped.

I need to remove the power window regulator unit and see what needs to be replaced. I checked with Corvette Depot and there are lots of repair parts – good thing about restoring old Corvettes is that virtually any and all parts are available.

The gap at the top of window is about 1/4″. I can live with that for the rest of the driving season.

Next I’ll be checking the diff fluid level and tomorrow I take it back to the alignment shop for more fine tuning.

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.