Stupid pre-buy questions

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jaywalkker

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I'm looking at a '72 dart slant6 that I'm thinking of buying to get hands dirty. Per the seller and observation, there's three immediate problems that would need fixing:

1. Intake/Exhaust gasket leak 2. kickdown linkage bushing replacement 3. Carb Rebuild

When I swap out the gasket, do I have to take manifolds to machine shop for polishing/leveling or can I just eyeball it for warpage, pits, and other potential vacuum/leak sources?

Where the kickdown throttle attaches to tranny it weeps transmission fluid. Should I (can I) just find a replacement bushing? Should I replace the entire linkage? The Entire kickdown actuator thingy mounted on tranny?

Sorry for the ignorance. I only have basic knowledge and haven't picked up shop manuals yet for the detailed specifics where these could probably be answered. I'm trying to outline in my head what's required for least $ to bring a garage stored car back up to baseline.

Thanks for the help.
 
After you remove the manifolds and clean up the gasket surfaces, use a straight edge to see if there is any warpage or unevenness. If there is, then you can take them to a machine shop to have them machined flat. Use a good quality gasket and make sure you don't over torque the nuts!
As for the transmission leak, (it is a common one BTW), you can replace the seal after the shaft and surfaces are cleaned up. It's kind of a PITA to remove and install while in the car, but it can be done. Your linkage should be just fine if it's factory and complete.
Do yourself a favor and get a factory service manual now before you go any further. The money you spend on it now will be paid back tenfold on just what you will save in time and headaches........
Good luck, and let us know how it goes!
 
Thanks Dartnut! I'm about 99% certain I'm getting the car so torque wrench & shop manuals will be the first supply run!

Quick question, what's the best way to clean the manifold/head faces of gasket material? I've heard ppl "scraping" off but don't want to gouge. And read of ppl wire brushing or sanding creating deformations that make bad seal and introduce vaccuum and/or leaks.

Thanks so much.
 
I used a gasket scraper to get them clean. Then I filled any pits with JB Weld, let it harden, and block sanded the surface flat, then checked it against a flat surface. One other thing you should check: stand both manifolds on their sealing surfaces on a flat surface, and loosely bolt them together, then check the adjacent flanges to make sure they are the same height. The triangle washers span from the intake to the exhaust flange at these points -- if the flanges aren't matched for thickness, the washer will be cocked, and it won't apply even torque. Also, these manifolds are so long that they expand and contract lengthwise as they heat and cool -- they are designed to slide a little back and forth under the washers. A cocked washer will keep them from sliding, causing a leak, and possibly causing a cracked manifold. Your manifolds should be matched since they came with the car, but you want to make sure (one could be a replacement). I also used Hylomar high performance gasket sealant, which doesn't harden, on both sides of the gasket.

Rebuilding the carb with a kit isn't that difficult -- the hard part is getting it really clean. You might be able to send it to a shop for that. I couldn't find a local carb shop that would work on a 1bbl.
 
I like using wire brushes on a drill or a dremel to clean mating surfaces
 
Regarding shop manual. Get a FACTORY CHRYSLER manual. Not Haynes. Not Chiltons.
 
You can download a lot of the factory service manuals here MyMopar - Mopar Forums & Information - Service Manuals

It actually doesn't have a 72 manual, but it has a complete '70 manual and a complete '73 manual for the dodge's. The '70 would be closer for a '72 because of all the changes made for '73.

Here's the '70 http://www.mymopar.com/downloads/servicemanuals/1970_Challenger_Dart_Service_Manual.zip

There's also a '72 Plymouth Chassis manual, should be pretty much the same

http://www.mymopar.com/downloads/servicemanuals/1972_Plymouth_Chassis_Service_Manual.zip
 
Thanks for the tips MVH! Quick question on the JBWeld for pits - what qualifies as a pit? Are we talking any holes or scratches that are BB sized? Smaller like #12 shot sized? Or just "any scrape, pit, gouge, or other deformation that's visible to the eye should receive treatment?"

Thanks for tip.
 
See this post (and its links) about manifold gaskets. You can fingerpaint with JB Weld if you really want to, but I've never found it necessary or beneficial. If the intake manifold is in really rough shape (which it almost certainly isn't), swap it; they're plentiful. If the exhaust manifold's sealing surface is in really rough shape the manifold is also probably warped and cracked and the heat control valve is also probably screwed up — just replace the manifold; they're available new (Yes, you can get 'em cheaper than the linked...and then you'll quickly come to wish you'd paid for the better-quality Dorman item). The '73-up type exhaust manifold is the only kind now available, which is fine; the '70-'72 choke thermostat won't work on it, but that's OK because the '70-'72 chokes are an exhaust-leaky pain in the nuts. Just get a № 1231 Electric choke kit.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

The transmission shift shaft seal is a common leak point and not a difficult fix; the part itself is easily bought. There is no need to replace any of the linkage parts themselves unless they are broken, which they probably are not.

Aside from the factory service manual, get the other two books in this thread.

Tune-up parts and technique suggestions in this thread.

Also read this one; most of what's in it applies equally to a '72.
 
jaywalkker said:
Thanks for the tips MVH! Quick question on the JBWeld for pits - what qualifies as a pit? Are we talking any holes or scratches that are BB sized? Smaller like #12 shot sized? Or just "any scrape, pit, gouge, or other deformation that's visible to the eye should receive treatment?"

Thanks for tip.
Click to expand...

Dan knows what he's talking about. But in my case the manifold was good, it just had a couple small gouges near one port, and a few pinhead size pits in some others. I figured if I was going to all the trouble of filing down flange surfaces to match, I would make the sealing surfaces perfect. Part of the reason my flanges needed work was that this was a mismatched set -- a 1977 2bbl intake and an unknown exhaust. That probably doesn't apply to you. At any rate, I have no manifold leaks so I'm happy.
 
Thank you for the copiously detailed advice and suggestions. When I get the car in the driveway I'm diving into all of it.
 
FWIW, I have had success in grinding flat a somewhat warped exhaust manifold flange with a plane sander, a coarse belt, and careful work. The usual process is to use a Blanchard grinder anyway.
 
A youtube shows a guy flattening a 4 cyl head by just sanding. For the final work, he spray-glues ~320 grit to a thick glass plate and slides the head back & forth, using its weight for force. Takes ~30 min to change from ~6 mil warpage to flat within <1 mil. Cast-iron would take longer, but the manifolds have much less area to remove. You also don't need the flatness of a head. I recall photos of slant manifold gaskets that are quite thick to handle warpage. As mentioned, you would want to first tighten the 3 attaching bolts with the faces resting on a flat surface.

For final bolting to the head, loosen the 3 bolts, snug the nuts to the head, snug the 3 bolts, repeat several times so all parts find their best home. Definitely read the slantsix.org link Dan posted. You orient the triangle and cone washers opposite from what intuition might suggest. If not, your exhaust manifold can crack, which is a common issue in all straight six engines.
 
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