CAR This is not a milk thread. I have owned my '74 Eldorado convertible for 2 years now but it's time for a build thread

[jelloslug]

With everything now cleaned up, I put the wiper linkage, the lower windshield trim, the cowl screen, and the hood gasket back on the cowl.











I need to polish the lower stainless windshield trim but I don't have the correct buffing wheels right now. I will buff it out later when I buff all the stainless trim.

 

[jelloslug]

I was planning on started the seat upholstery over the Christmas/New Years holiday but I had an opportunity to buy a really nice complete convertible top assembly. I quickly shifted plans and grabbed the top before it got away from me.



It's an aftermarket replacement top of a good quality manufacturer and it came with all the actuator parts and new weather stripping. I paid less for all the parts than just what the weather stripping would cost.

 

[nosaj]

Nope, I'm an engineer.

super nice work. A friend and his dad have been doing restorations for Sam near 50 years. Your work is a lot nicer than a lot of “ professional “ work they have corrected.

 

[jelloslug]

With the new top safely stored away, I started taking my old top out of the car. The first thing I had to do was take all the interior panels I put back into the rear of the car back out. I then separated the top from the lifting arms. This top is what is referred to as the GM "scissor top". It was GM's first (I think) all electric top and was used on all full sized convertibles from '71-'76. The top fabric and it's roof bows bolt to the lifting arms and also clip to the body shell opening. I had to unbolt the bows and unclip the top from the body.











Here you can see why it's called a "scissor top". These arms are the main lifting arms and when fully extended, form the upper opening where the side glass closes into when the top is up and the window are closed. The ends of the arms lock into the windshield header with pins and the front bow (removed in this pic) has the locking handles to secure the top to the windshield header.






Here is a video (not mine) of an Impala with the same top being run up and down with no fabric on it so you can see how it works:





Normally when the fabric is on the top, there is a cable on each side that pull that back bow and 2nd bow in place. With no fabric on the top, there is no place for the cable to run.

 

[jelloslug]

My original plans were to just unbolt the entire top with the lifting arms and actuators all in one shot. It turns out that the whole assembly weighs about 250lbs so that was out of the question. With the top itself out of the way though, I could remove each lift arm out by itself which made the job actually manageable without gantry hoist.






With everything out of the top well, I wanted to focus on cleaning up the well and the trunk since they are the same space. If you recall, I had already started on the trunk some time ago by taking out all of the old carpet, sound deadener material, and some of the old seam sealer. I continued on and removed the remainder of the seam sealer and the body plugs.





I also removed the trunk pull down latch, the rear wiring, and the fiber optics for the rear lamp indicators.







With everything out of the trunk and all the old seam sealer removed, I coated everything with POR-15.

 

[jelloslug]

After the POR-15 dried, I put new seam sealer in.

 

[jelloslug]

One of the thing I want to do is make the trunk floor flat. I probably will build a wooden false floor to bring the floor height up to the height of the hump in the middle but for now, I want to fill the punched ribs in the floor. I used strips of the butyl sound deadener to fill the ribs.









With the ribs filled, I put a layer of the sound deadener over the entire trunk floor and top well.

 

[nox]

One of the thing I want to do is make the trunk floor flat. I probably will build a wooden false floor to bring the floor height up to the height of the hump in the middle but for now, I want to fill the punched ribs in the floor. I used strips of the butyl sound deadener to fill the ribs.

What's the reason for the flat floor? Just aesthetics or bigger plans down the road?

 

[Jcolman]

I'm impressed.

 

[jelloslug]

While I had the trunk pull down latch out, I needed to repair a wire on the motor and take care of a little rust on the motor shell. The pull down latch assembly lives inside a metal shell and there was a mouse nest in it. I'm guessing that mouse pee rusted the housing. The wire looks like it was chewed but every one I have seen looks like this.








I pulled the motor off and took the end cover off to replace the wire.






I ground off the rivet that held the wire in place and removed the old wire.







I then made a new wire and soldered it in. Once it was soldered in, I cut it to length and crimped on a new terminal.

 

[jelloslug]

What's the reason for the flat floor? Just aesthetics or bigger plans down the road?

In the convertibles, the spare tire sits to one side rather than up on the shelf like all the other cars. Since the trunk was not really designed to have the spare sitting over to one side, it half way sits on the hump in the middle. In all the other cars, the jack is under the spare tire but in the convertibles, it's mounted in the same place but now it's out in the open. What I want to build is a false floor that raises the floor up to the height of the hump so the spare will sit flat. This will also give me a hidden storage space to put the jack.

 

[jelloslug]

With the wire fixed, the trick now is to get the motor back together. When it was new, they put the rotor into the brush holder, latched the brush springs, dropped the stator over the assembly, put the gear on the end, and then peened over the end of the shaft. Since I can no longer get the gear off the end of the shaft, I have to hold the brushes open so I can put them over the commutator down inside the motor. I made a cut washer on a string that would hold the brushes in the latched position but still allow the rotor to slide between the brushes. The cut in the washer allows the washer to slide around the rotor shaft once the rotor is pushed down. Once the rotor was in place, all I had to do was pull the washer out with the string. It took a few tries but it finally worked.








And here it is back in the car.

 

[jelloslug]

Another thing I tried out was some more fake dichromate finishing on some of the AC hoses. This hose was still in serviceable condition but it looked crusty.









I used a brass brush to clean up the corrosion and then taped off the hose and the fitting end.






I then spayed it with metallic gold and while it was still wet, metallic silver.








I did the same process on the other hose also.

 

[jelloslug]

Back to convertible top fun. Here is one of the lifting arms. With the mounting brackets and gearbox, I would say that it's easily 60lbs or more.






The lifting arms seem to be in very good condition with only some surface rust on them. They are exposed inside the car with the top up so they will need to be refinished. I started out by removing the very heavy duty mounting bracket. The bracket weighs about 20 lbs and that large bolt is a 1-1/8" hex.







Next I removed the worm drive gearbox from the arm assembly.







And here are all the parts of the lifter arm assembly. The push bar and middle joint of the arm are all riveted together and at this point, I'm not going to cut the rivets out as it appears that some of them were installed before parts of the arm were welded together.

 

[jelloslug]

The worm drive gearbox is very robust and it not an item that commonly fails. It gets it's input power from a central motor mounted between both arms and the power from the motor is transmitted via a steel cable similar to a speedo cable. Both arms are driven by the same motor and synchronization is achieved by manually closing the top with the cables unhooked and then hooking both cables up. The gearbox was not in horrible condition but all of the grease had hardened and it needed to be repainted.











The input shaft had to have the smallest roller thrust bearing I have ever seen. The OD of the bearing is about .375"






The top of the gearbox has a rubber flap that is supposed to help keep debris out of the inside but the bottom of the box had a nice collection of ground up bugs and leaves in it.

 

[BigBronco]

This is a great thread!

 

[cowboyrps13]

It's back

 

[jelloslug]

It's back

Hopefully I will have a little more to post tonight or tomorrow. I've been really digging into the entire convertible top assembly so I know how it works completely before start putting it back together.

 

[jelloslug]

Here is a little update. I put the drivers side actuator gearbox back together after I cleaned and painted everything.

 

[jelloslug]

I then painted the mounting brackets and mounted the actuator back into the bracket assembly.

 

[jelloslug]

My top frame assembly is in much better overall condition than the one on the top assembly that I purchased so I have decided that I will reuse mine and just move the fabric over from the old frame to mine. This will give me a chance to completely go over all the parts of the frame and to make sure that the top is as clean as it can possibly be. It does have some soot on the underside from the fire that was in the car it came from. Here is my front bow. The front bow on the top I bought is rusted on the ends so I don't want to use that. The only rust in mine is under the tack strip on the front edge.









I sand blasted it and all the rust came out. There was minimal damage and only two of the tack strip retainer tabs had any rust damage.





One of latching handles had always been a bit stiff. It turns out that the stamping that make up the body of the handle has a little bit of extra metal sticking up and it was grinding into the handle itself when opening the latch.





I ground down the bump and now the latch opens smoothly.

 

[jelloslug]

Since I already had the drivers side actuator and arm apart, I went ahead and took the passenger side apart also. It was very similar to the drivers side with minor surface rust and caked on grease in the gearbox plus the ground up leaves and bugs.










One thing that I don't know if I have mentioned before is that this car had almost every nook and cranny filled with dirt dauber wasp nests. If it was hollow and had an opening, there was a dirt dauber nest in it. Here is what came out of just the passenger side lifter arm:





And there is the lifter arm frame after sandblasting:





I hope to have both lifter arms with gearboxes and the front bow painted this weekend and hopefully all of those parts back in the car to start aligning them. I just got the new tack strip material in today and that was the last part I needed for this set of parts.

 

[Achmiel]

Loving the progress! Thanks for the update!

 

[jelloslug]

Loving the progress! Thanks for the update!

I just got done with more tonight so I'll have more to post in a bit.

 

[jelloslug]

So the first coat of paint has cured on the front bow and I sanded the part that you can see when the top is up to give it a second coat.







And I gave it a heavy second coat.