PolCat-76-Avion wrote:

New member here! Just joined the rv.net site. We recently bought a 1976 Dodge Avion 22 foot rv. MB400 chassis 440 engine. It is in really good shape except that a previous owner painted it with a brush.




Now that it is getting colder I tried to slide the temperature selector to heat but nothing happened. The wire was disconnected from the valve in the heater hose. The valve does work the cable doesn't move. How do I get to the back of the heater control part of the dash?

RvFNG76 wrote:

Ok brakes done axle seals done bearings done pinion seal done just finished draining out the gear oil that looked like chocolate milk mixed with garlic mud. Next question is what grade grade oil as it is a limited slip. I do have 3 quarts of 75w90 conventional limited slip oil. Will it work or what's everyone running I've heard the Dana 70 recommends 80w90.

StingrayL82 wrote:



Great looking rig! In order to have easy access to the cable, you have to remove center portion of the dash. In my case I was lucky, because our MB300 was not ordered with factory A/C; Monaco installed an aftermarket unit from ARA that was self-contained in a plastic housing....removing the housing gave me full access to the heater components, which was nice because the ducts were completely rotted.

My cable was frozen too, but in my case it was the valve that sits on the heater core that was completely rusted up. If your valve is in good shape, take care of it, because IF you can get a new one, you're going to pay through the nose for it. I was able to find a NOS unit, but it set me back $125.

What I would do is disconnect the cable at the valve and try sliding it back and forth to free it. Shoot some WD-40 into the cable sheath and slide it some more. That should take care of your problem.

Good luck.

PolCat-76-Avion wrote:



I can slide the wire into the cable but the slide on the dash does not move. I am thinking it is off the slide or broken off the slide.
Thanks

PolCat-76-Avion wrote:


I can slide the wire into the cable but the slide on the dash does not move. I am thinking it is off the slide or broken off the slide.
Thanks

PolCat-76-Avion wrote:

I took out the radio and was able to access the controls. Looks like someone else was in there, white wire tie holding cable in place and the wire is broken. It's a real bugger to get the control loose let alone out. Looks like I will be putting a "choke cable" through the dash and then to the valve. I have a manual for 1976 B100, B200 B300 but not much looks like the MB400. Doesn't even call out the 440 motor only goes to the 318.

Griff in Fairbanks wrote:


You're going to need to pull the control panel, located above the ignition switch. Usually one or two screws on the bottom or sides. Careful, the top is usually held in place by a tab on the panel that goes behind the dash sheet metal. After the screws are out, pull the bottom of the control panel a little bit, then the panel downward a bit to release the tab for the dash. (I've seen people break that tab.)

Look for corrosion or gummy lubricate. A bit of PB Blaster or Kroil, allowed time to work, will free it. (Spray cans can get messy so I sometimes spray on a piece of scrap metal and pick it up with a cotton tipped swab to apply it.) It may take a day or three for the PB Blaster or Kroil, applied repeatedly, to free the slider.

Once it's free, clean with brake cleaner. Re-lubricate, preferably with white lithium grease, and reassemble.

Do NOT use electronic contact cleaner! That "attacks" plastic, causing it to disintegrate.

Go slow and don't force things.

If you get stumped, yell and post pictures.

Note: WD-40 really isn't a penetrating oil or a lubricant. It's meant to inhibit corrosion by displacing moisture. (WD-40 = Water Displacement, 40th formulation attempt.)