1989 C4 Functional Restoration

[SirReal63]

I believed I mentioned I was frugal/cheap/whatever. When I bought the car the center caps were not on it. I found the center cap bolts, well, I found 3 of them and no wrench. These are unique to the 88 and 89 I believe and the 4 bolts and wrench are available for $129.00 Yeah, no way I am paying that for 4 cap screws in stainless and a wrench that may get lost again some day. I pulled out my tap and die master set and found the thread pitch, diameter and length and ordered 10-M10x35mm 304 stainless socket head cap screws for $10.00 and I have plenty of orphaned hex keys. Problem solved. The 0-rings on the center caps were either missing or disintegrating, I used my caliper to measure the groove and ordered 10-150mm OD, 143mm, 3.5mm thick Nitrile O-rings for $7.99 which gives me 6 extra cap screws and 6 extra O-rings, sounds like a plan to me. I ran a tap through the screw hole because they were filled with debris and dirt. The new cap screws fit like a glove.

Out with old and missing...



In with new new and functional...



I am not really worried about someone stealing my wheels, they are old and ugly. I am also not worried because we are remote enough and in a relatively crime free area. We only lock our doors if we are going away overnight but we have a farm, we don't usually have the luxury of overnight trips. If someone should try and they get past the dogs, the security cameras will pick them up and the insurance money will get me some new wheels. I will polish out the stamped writing on the cap screws when I refinish the wheels.

 

[SirReal63]

It is going to take another coat or two in some places, mainly where the stains are the worst...the flash really brings it out, it isn't as bad with eyeballs.

 

[SirReal63]

That is about as good as I can get it for now. It isn't perfect and has a sheen to it. Perhaps a little time in the sun will help, or at least show me it needs another coat.

 

[SirReal63]

I decided to tackle the front weather strip over the windshield. I had a feeling this one was going to be difficult, and it was. The outer layer looked mostly intact, supple and did not leak. The ends where it goes down the door frame from the windshield was the worst looking part, obviously flaking and brittle so I had ordered a latex replacement.

Yes, it was really bad once I got into taking it off.



I found yellow w/s adhesive, black w/s adhesive, silicone caulk and what looks like Gorilla glue holding it down. It was slightly frustrating taking it off. I have used the 3M adhesive remover in the past and wasn't really impressed with it for removing adhesive residue and had zero faith it would soften the mess I was dealing with. The top strip was the worst, I ended up with a small wire wheel on a drill to get the bulk of the concrete hard adhesive off. I hated doing it as I meant I would need to repaint that part but after closer examination it needed to be repainted anyway.. Once I had the bulk off I decided to try brake cleaner soaked paper towels. Surprisingly, that worked really well, I just had to keep the paper towels moist for about half an hour and it softened it up enough to scrape/brush/pull/roll it off.



The brake cleaner had a nice reaction with the latex remains and the adhesive remains. I got about 90% of it off and out of the grooves with this method. It took exactly one can of brake clean to do the job.



The final results. It only needs a little touchup with the plastic scraper to get it ready for the new w/s

 

[SirReal63]

It has been a busy few days. The front windshield weatherstrip is done, my local hardware store was out of flat black and so was I. I can/will paint the windshield trim at a later date, the way the weatherstrip fits I can still do it without getting pint all over it. The w/s slid into place like it should.



I decided to work on the interior as I need to go over the wiring in the burn zone and the interior will be in the way of that. Most of it came out with absolute ease. It was surprisingly clean for the age and the jute was even in great shape, which was a surprise on a convertible as they have more of a tendency to leak, but this one appears to not have a massive leak. I vacuumed the carpet prior to removing it but have not cleaned the floorpan in these pics, not a bad amount of dirt/debris for 34 years.

We will get to that ugly duct tape in a little bit, as well as the Bubba surprise under it.

 

[SirReal63]

I have been guilty of not doing things as well as they can be done in the past/present/future, sometimes we make poor decisions to get things done and onto something else. I am the 7th owner of this car so really not a lot will surprise me but I have to admit surprise with this one. I knew there was duct tape in the center console and assumed it was related to the burn spot. The cupholder door did not open all of the way as the duct tape blocked it from having a full range of motion.

I started peeling back the layers...




Under the duct tape was a foil covered butyl rubber sheet very much like Boom Mat that had been cut into strips and molded in place of and on top of the rubber shifter boot. This butyl is very similar to mass loading you would use to stop panel vibration or sound deadening. This was the stickiest stuff I have tried to remove in a long time. I probably would have gone a different direction on that repair but other than the cupholder lid not working correctly, it did the job. The shifter knob is hacked up pretty bad, I may have to find another shifter mechanism or try to make this one right again.

 

[SirReal63]

Finding this was a real bummer, trying to source parts now.

Missing shifter guides and shims which explains the side to side slop in the shifter. If I cannot find the correct ones I will have to machine them out of Delrin. I have a new boot on the way so after I get the shifter issues worked out I will be able to seal it up.

 

[SirReal63]

It has been a busy few days here.

I began working on the tranny tunnel burn zone. It was way worse than I expected. After getting the interior completely out, the areas that were black were also very fragile, like you could push your finger through them fragile. I mixed up the last of my clear penetrating epoxy and went to work saturating all of the dark areas that had got hot and crispy. This worked great at stabilizing the fragile pieces and making them strong enough to glass. Unfortunately I could not get to the backside of the area, to massage it back into the proper shape, I would have to remove a lot of things to get to the area and I wasn't ready to drop any of that yet.

This is the area in question, the hole was the least of my concerns as it was the easiest to patch.



I have played with fiberglass off and on for over 40 years and this was the ugliest repair I have ever done, it is shameful and embarrassing but I admit to the bad right along with the good.

One layer of biaxial glass and two layers of .75 oz chop gave me the structure back and I tried pulling the collapsed areas back in from the only side I could get to but it didn't really work as intended so I mixed up a batch of thickened epoxy to try and smooth out the uneven areas and after curing I sanded a little to get the highest bumps out. I got concerned about weakening the area with aggressive sanding and chose to leave it ugly and strong instead of smooth and potentially weakened. I can only imagine what the backside of this looks like. Not pretty but I can pound on it with my fist and it is strong, just embarrassingly ugly. It was cold enough in the shop that the epoxy had a hard time kicking, even with a heater blowing directly on it everything wanted to sag which made additional layers of glass an issue that wasn't needed for strength.



Next I moved on to the floorboard cracks. They were not as bad as I expected, the upper seam and L Channel was intact but the junction of the floorboard to the beam was cracked. A little grinding, sanding chopstrand and bonding later and it was repaired on both sides. I used aluminum duct tape along the bottom to keep the epoxy from running put which allowed it to soak in nicely and will get cleaned up at a later date. A little thickened epoxy and formed fillet and the area was repaired. was still fighting the weather and over 24 hour setup times with the epoxy which made all of this way more fun than it needed to be. Absolutely ugly but also not visible so only my pride is injured as there is zero need in grinding and fairing here.



I covered the repair and the rest of the floor pan that was corroded in topside paint for added protection.



I absolutely could have spent a week of grinding and glassing to make this look near perfect but I did not see the point. I will live with the guilt of these pics for the rest of my life but no one will fall through and water will not get in from the bottom. lol

 

[SirReal63]

The shifter was my next problem. The guide bushings were long gone and the shifts were sloppy, well, actually the 3-4 and 4-5 shifts were sloppy, the 1-2, 3-4 and 5-6 shifts were ok, just moving the gate side to side was really sloppy. After discovering the missing bushings it was obvious why.


These bushings are not available, I looked everywhere and I am usually pretty good at finding obscure things. I did find bushings for other ZF transmissions and the design is very close on them. You can still get the bushings for Ford's ZF trannys used in light and medium duty trucks so I reached out to a seller of these bushings for some measurements in hopes they would either work or could be modified to work.

The S6-650 bushings are the same design but with a crucial difference, the hole size for the pin that fits in them. The S6-650 uses an approx. 10.2mm hole and the S6-40 uses an approx. 11.95 hole. I had hoped I could bore it out to the correct size but that doesn't work, there are little voids around the hole that weaken it if bored out.





I had on hand some 3/4" Delrin rod which fits perfectly in the channel the bushing fits in. I decided to bore out the rod to press fit the pins, but the alignment would be slightly off, based on the dimensions from the S6-650 bushing. I drilled the hole off center to get the pis as close to the correct position as I could. I undersized the hole and had to use a c-clamp to press the pins on in hopes it won't rotate with time. I cut the S6 bushings to fill in the top of the rod and melted some Delrin shavings to fill in the void. Melting Delrin or any UHMW plastic isn't as easy as it sounds, it does melt right before it ignites, so it it was a challenge to get it melted and capped before it cooled. I did manage it with many attempts. The repair should be good and hopefully it lasts. If it does not last I can get a sheet of Delrin and mill it to the correct shape but I used what I had on hand. The shifts are now precise and the slop removed.



This is not a perfect repair, but it is acceptable and massively better than what it was before.

 

[SirReal63]

Time to start getting the interior back in this poor old car.

I bought 36 sq ft of Kilmat to mass load the drum like panels on the car. I know this car will never approach the level of quietness that our other vehicles have, and being a convertible makes it even worse. The best I can hope for is help reduce road noise a little and add some insulation to help as well.

It is not necessary to cover every square inch of surface but the more the better.

36 sq ft went farther than I expected.




Next comes insulation...