Cadillac Seville / Cadillac Eldorado Forum Discussion, 1995 SLS: Torque strut broke! HVAC plastic cracking in Past Cadillac Vehicle Discussion; Otherwise known as the driver's side dogbone holding the engine to the brace under the hood. The long one on ...
Otherwise known as the driver's side dogbone holding the engine to the brace under the hood. The long one on the driver's side broke! Loud cracking sound. When the rubber in these things gets hogged out, the constant pounding back and forth will overstress them and they will break--they're just aluminum. I checked out the short one and it's hogged out too, so it's getting replaced also before it breaks. Not surprising at 216,000 miles but not something I'd routinely check.
While I was under the hood I noticed that the plastic that covers all the heating/air conditioning stuff up against the firewall was literally cracking into pieces with large gaps between the pieces. Just touching it caused more cracking. It's disintegrating! I used the handyman's cure-all for a temporary fix (I duct-taped it together--black Gorilla duct tape so it blends in better, but duct tape nevertheless). There are parts down between the firewall and the rear header that I can't reach. In any case, it all needs to be replaced. Can this be done without taking the engine out? Tolerances are kinda tight back there. Also, I've noticed since taping up the cracks that the A/C doesn't seem to switch between the dash vents and the defrost vents any more. It was doing that on a regular basis before. Strange.
I can not get more than 2 years out of my torque struts, the rubber on the engine side gets cooked and literally disintegrates into dust. I use to change the torque struts almost every year until I figured out this. So now I flip them as frequent as every 8-9 months and that's how I get 2 years.
The same issue (heat) affects the plastic on the firewall and I am pretty sure I will have this issue as the car ages (we are only 2 years apart). I don't se how you can change that plastic with the engine in...
Yea that front mount is shot if you broke a dogbone, prob need to change all of them. As for the rubber wearing out quickly, I was thinking about using poly bushings from energy suspension and swapping those in for the rubber.
N* is correct. You can't change the HVAC housing on the firewall with the engine in place. That said, it's my understanding that they are not available anyway and a junk yard part would probably be no better. Personally I'd patch it as best as you can, but not with duct tape. That stuff will melt off with the slightest heat. You might try self sticking mesh drywall tape. Cover everything you can get to. Then wear a glove and smear the entire area with silicone caulk or maybe fiberglass. The possibilities are only limited by your imagination.
Some good ideas here! I was thinking of smearing the firewall plastic with something... just didn't know what. It is definitely a high heat area. The duct tape is just covering the top part mostly as I couldn't get down into the lower parts. The flexible mesh is a good idea to keep caulk (or whatever you use) from leaking into the HVAC system. I'm thinking maybe fireplace/chimney caulk. It will resist pretty high heat. Fiberglass might be easier to work with though. That chimney caulk is like liquid gooey asphalt.
Flipping the dogbones every few months is a good idea too. I tried to get the good bushing out of the broken dogbone (the radiator side wasn't disintegrated) and it just doesn't want to come. I pounded on it and tried to wedge a screwdriver in under the rubber without luck. The aluminum is recyclable to support the Alternative Education Center where I (sometimes) work. But the recyclers don't want steel or rubber contaminating the aluminum. I think I'll just cut the top half of the circular area off and pull the bushing out. They don't care if the aluminum is in broken chunks.
Thanks for your ideas.
Ranger, on his car are readily available and are no more than ~$30 for the set. Rockauto has the parts in about 2-3 makes last time I checked.
The only reason it broke (unusual again) is because there was no rubber bushing anymore and the engine just yank it repeatedly.
As for recycling the aluminum part if you don’t need the bushing (and you don’t) just use a short pipe slightly smaller in diameter than then inside diameter if the aluminum housing (where the bushing goes) and knock it with a big hammer, that rubber will just fly out. I do this all the time when I send mines for recycling.
Yeah, I guess in his case just replace them and they'll outlast the car. I think I have the OP confused with someone else who said that they repeatedly replaced them because the rubber grommets kept failing.
Well I replaced both of the dogbones, and with 216,000 miles on the car, the new ones will probably outlast the the car. As far has the HVAC cover, I found an intact and still flexible one at a local junkyard. It's on a 95 DeVille, so I don't know if it's identical. The engine is out of the DeVille so the cover is easily removed, but I don't want to buy it if I can't get it in my car, which is a '95 Seville. The old cover will come out easily enough. Just touch it and it breaks up. But putting the other one in looks impossible. Watcha think?
I'm surprised we don't hear more about the disintegrating HVAC plastic; it seems to get very brittle over time. I replaced my HVAC cover on my 2002 Eldo while the engine was out for case-half seal. Huber Cadillac in Omaha found me an OEM replacement ($300 or so, if I recall, for the part). Plastic on the air filter box seems extremely fragile, too. One of the clips broke off, and I have a small C-clamp keeping it closed securely (safety-wired so it doesn't loosen or drop if it does). I started down that path with duct tape, Gorilla tape, etc., but I wasn't happy about it...especially if i ever went to sell it with a commando repair job (not that I have anything against commandos).
I know. I've been through those threads already. I was just mentioning my surprise at this recurring wear-out component that is not easily replaceable. I have studdied this car and the writings of the high priests who share their erudite knowledge on these forums to further the preservation of these wonderful vehicles. Thank you, Ranger, I count you among the wonderful fountains of knowledge and advice. Best to all.