Speedometer Cable Keeps Melting

[MSN Member]

From: CaressMaster
Sent: 12/21/2003

Hi I recently purchased my first class A motor home. It is a 1979 Winnebago brave .   I was told that the speedometer cable keeps melting due to the fact you can not get the steel cable replacement for it you have to go to a Dodge Dealer and all they have is plastic replacement one,s is there away to solve this problem. The rig is in great shape inside and out with low miles.65,000 miles give or take a few.I plan on working on it in the spring.If anyone has any info that can help me it would be great. thank you.   yours truly Buffalo mike

[denisondc]

Sent: 12/22/2003

I don't know if yours has the 360 or the 440, but I suspect the reason the speedo cable melts is because it runs too close to the exhaust manifold. Mine is a 72 with the 413, and I had to replace the handbrake cable because it had gotten roasted. I then made up a heat shield of thin aluminum, in two pieces 9 inches long by 6 inches high. I slid them into the space between the exhaust manifold and the items running past the engine on the drivers side, the handbrake and speeo cables, some engine wiring, and the brake lines. I held the heat shields against the frame rail and away from the manifold with springs from the hardware store where I bought the roll of -aluminum roof flashing-. A single piece 18 inches long by 6 inches high was too big to slide in, so I made it in 2 halves. You cant have the heat shield right against the exhaust manifold, because the manifold needs to throw off a lot of heat or it might crack, but just stopping the radiant heat from getting to the parts will help a lot. You want the shields easy to remove for checking compression, cleaning the spark plug threads, changing spark plugs and re torquing the manifold nuts. The last 3 pictures in my photo album; denisons 73 D22T, on about page 7 or 8 of the photo albums (no longer the case since we have a new photo album), show the situation. I did the work from inside the wheel well, with the drivers side tire removed and the axle supported on a sturdy rack of 6 by 6 lumber. You need to hold the heat shields in firmly, so they don't blow away at cruising speed. There was no sign that my RV had ever had heat shields there.
While you are working on your rig, you should check that all of the wiring that runs beside the engine is well supported, and can not droop onto the manifolds! Also, find out where your fuel filter is, and buy some extras - the type you can see into, so as to check when the rusty silt from the fuel tanks is starting to clog them up!
denison

[MSN Member]

From: larry060748
Sent: 12/22/2003

Mike
I understand about melting cables because heat from my 79 brave/360 engine/27 ' had melted the factory speedometer cable for its original owner and the current cable was needing to be replace. I took the heat shield ideal that denison make and created my own shield for my 79 brave. I used a piece of aluminum from the bottom of my neighbor's old home entrance door. I took the original brackets off that hold the wiring to the frame. These 3 brackets are beside of manifold were I intent to attach the heat shield. I then flatten the brackets into a 90 degree angle and fasten them to the aluminum shield with small bolts and reattached the brackets to the frame in their original place.  I also went to the local lumber supplies store and purchased two small springs to keep the shield top from vibrating. I did all the work from inside the wheel well, and unlike denison I was able to slide the one piece of aluminum between the manifold and frame fairly easy. I will know this spring when I take the brave out for my first trip if the shield does its job.
Larry12@wwgap.net

[OldEdBrady]

Sent: 10/21/2005

I've been lucky and haven't had to replace the cable in the Whiny Beggar.  BUT, when I changed cables in vehicles,  I've always gone to a parts store and purchased one the the generic things.  Usually they are far too long, and have to be cut off, but they have always worked.  Might be worth a try.

[jbmhotmail]

Sent: 10/23/2005

If your speedometer cable keeps melting, have you checked to see if your engine ground strap is in good condition, it's possible that the speedometer cable is acting as a ground strap and that may be one of the reasons that it is melting.

[73dodgeTitan]

thanks for the ideas on this - very helpful

[73dodgeTitan]

My speedometer got too close to the manifold and melted. I was able to get a custom cable made. The new one is steel - so no more melting issues.

I mailed my old cable to Kris's Mobile Speedometer ServiceInstrument Repair Specialist - he did it in one day and had it back out in the mail to me.

[ClydesdaleKevin]

If you have the contact info and/or website for the guys that did your custom cables, I'm sure that would come in handy for a lot of us later on.

Thanks!

Kev

[73dodgeTitan]

Here is the web address http://www.speedometer.org/