Speedometer not working

[m37jarhead]

Before hooking up the speedometer cable to the transfer case I did the following:
1. Removed the inner cable and lubed it with "speedometer cable lube."
2. Jacked up a rear wheel; started the motor and checked to see if the
connection at the transfer case was rotating. It was.
3. Connected the cable to the transfer case. Routed cable to the dash.
4. Again started motor and put tranny in gear to spin the rear wheel.
5. Result: Inner cable not turning. Connected cable to the speedo just
to make sure inner cable was seated. Nothing.

BTW, it was no small feat to connect the speedometer cable to the
transfer case in the tight space between the floor board and the
transfer case.

Any suggestions would be appreciated.

[Cal_Gary]

I'd start from the top as noted, as each step gets progressively harder:

Ensure your speedometer is ok by giving the gear a spin from the back-see if the needle jumps-use a drill if necessary;
Check the cable end that goes into the speedometer to ensure it is "square" and not rounded off;
Yep, the connection at the transfer case is a tight fit, and you want to make sure you don't have a severe bend in the cable just outside the mounting point-can sound noisy and can also cause a break.
Next, you may need to disconnect the cable from the transfer case and check the cable pin on the transfer case end to ensure it hasn't come loose from the cable itself;
Finally, check the cable mount and internal gear that goes into the transfer case to ensure all is well.
Good luck-let us know what you find.
Gary

[m37jarhead]

Gary:
Yeah, something's not right. Will start over again this morning and re-check it all.

When the cable is finally attached to the transfer case there IS a sharp bend in the
cable caused by the lack of space with the floorboard. I'm surprised Dodge didn't
engineer a 90 degree fitting off of the transfer case to avoid making the cable bend
90 degrees. It sure was a son-of-a-gun getting the cable on to the transfer case.

Guess if I ever take out the transfer case I'll attach the speedo cable before I
re-install it. Life's too short to fight this problem.

Will post today's findings.
Jerry

[ZGjethro]

I will jump in here with a related question. My speedometer works, and is right on with the roadside speed radar stations around town. At lower speeds, the speedometer fluctuates a lot, and around 25 mph it evens out. Is the cause a worn cable or housing, or is the problem in the speedometer itself?

[Cal_Gary]

Your symptom sounds more like a frayed cable than an issue with the gauge itself-might be worth pulling it out and taking a look.

[m37jarhead]

As Gary has pointed out, the cable probably needs to be pulled, cleaned and lubed.
Use "speedometer cable lube" available at NAPA and other auto parts stores.
Auto Zone did not have it at my local store.
Should stop the fluctuations if the there's not other problems.

[Cal_Gary]

Jerry, here are a couple of pix:

[Cal_Gary]

Sorry, it only allowed one photo-hope that helps,
Gary

[m37jarhead]

Thanks Gary for the pic. It matches mine and IS a tight fit.

I pulled the speedo drive unit off of the transfer case. A 7/8" deep well works great.
The inner shaft has a small gear and "nub" at the end that seats into the inside of the transfer case.
The "nub" is clearly broken off and the gear is in very poor shape.

I have another speedo unit but am concerned about the the broken off, nub piece.
Mirrors do not show that the broken piece is still in place. Probing with
magnets got no results.

I suppose I'd better drain the transfer case and try to locate the broken piece.

JB

[m37jarhead]

BTW..........it's ONLY 113 degrees outside today. 5 a.m. comes early but at that time of day
it's in the high 80's or low 90's. I can get a few hours in before it turns into a boiling caldron.

[T. Highway]

m37jarhead,

Isn't that a dry heat though?

Bert

[m37jarhead]

Replaced the speedo drive gear mounted on the transfer case.
All works well now.
The old inner gear on the shaft was well worn and not seated
properly with the tip of the shaft broken off.
On to the next project on the M.
JB

[Cal_Gary]

Well done Jerry! I was wondering earlier today about this situation, and if you solved the problem-nice job!
Gary