So I took the old girl for a spin a few weeks ago, suddenly the needle started flicking… if I was doing 45 it was flicking from zero to 60…
A few months ago, I had needlessly pulled out the dash, which became an opportunity to change dash bulbs etc.
I had figured I might have not reattached the cable correctly, so I pulled the dash out again tonight… to find the cable was still in there.
Only then did I notice the mileage 49999.9
It may be that there is a gear jumping internally, against trying to turn all the registers? Has anyone else had something similar? If so what did you do? I am wondering if it is the cable square jumping inside the driven receiver? And whether to pull the cluster and drive it through 50000.0 on the table?
Most likely the speedometer cable needs lubrication. If so you will need to pull the dash then pull the center cable out of the speedometer cable housing. Stick the center cable into a grease container (wear rubber gloves) then reinstall it.
I had that problem with mine, I replaced it with a wccc used part. Playing with the old o e I discovered it was the odometer gear, the needle bounce was the gear driving the odometer wheel skipping. I did find out my drill does 70 mph.
So I tried taking her for a spin, without putting the crash pad in. This way i could reach around the side of the cluster and ensure speedo cable was seated correctly. (Which it was)
At trundling pace it is a kick about every hundred yards, and the odometer did not move. I can hear a skipping gear.
(I was idling in gear rolling up drive, leaning over listening to speedo whilst reaching around cluster with left arm … my wife was walking down the drive from horses, she thought I was slumped over the steering wheel having had a heart attack…she was not happy.)
I am now convinced odometer is jammed at 50k miles. I got it at 41k so no problem until now, to my preference would be to get it over the hump, to 50001, and then worry about it in 10 thousand miles.
Are these things easy/safe to open and sort out? I am in Aus, so it is not like there is a wrecker with Cougar clusters near me.
Is there a secret?
Is the near 60 year old plastic going to fall apart?
I am hoping to attend a cruise this Saturday, so hoping for simple fix to plop cluster and crash pad back in for Saturday.
With the dash pad already removed you are half way there. You will need to remove the complete cluster from the car, then remove the woodgrain face panel, then separate the white plastic housing from the rear metal housing. The white plastic housing can be brittle depending upon the weather conditions the car has been through over the years. Here where I am the plastic housing very rarely are brittle. Once the 2 housings are separated the speedometer can be removed from the metal housing. With the speedometer removed all the gears are exposed so you can easily inspect them for any damage. You can turn the piece that the cable goes into by hand to watch the gears move and see the needle move. A visual inspection may show you the problem.
Ugh, it does sound like your odometer is stuck. Wish I knew more about the internals of those. Wonder what would happen if you used an electric drill to spin it backwards and then snuck up on 50k again slowly. Maybe you could somehow get past the jam?
I told my wife what I thought would be a funny story about your experimental test drive while slumped over the wheel. She shrieked “YIKES, don’t EVER do that!”. Then I remembered that she hates Monty Python too. Different sense of humor - lol!
That did not work… so I took the faux wood grain off, then I thought I could maybe assist the registers whilst spinning the drive (if I removed the lense) . I was worried the lense mounting plugs were plastic-unobtanium-55-year-frangible-fallapartium, so I had an alcoholic lemon squash for bravery and gently prized them off. (They are metal).
That did not work either… so I flipped it over to take the “back off” …. I could see some chalkiness, so a second “bravery” lemon squash later I had a go… Which ended up being put back any screw that was not an edge screw and flip over (it is the front that comes off).
Notice the indexing thingy that I put back around.
I then put everything back together, waited a couple of hours (to make sure those bravery lemonades were out of my system) took it for a night test drive ( that I never do lest I hit a kangaroo)…
Annnnnd it worked! For exactly 10 miles …. Then jammed again 50010… so tomorrow I do it all again but keep going until I have the speedo and odo broken down completely… it will probably take three bravery sherbets this time!
That was Monday, yesterday I pulled the crash pad (again), then pulled out the cluster (again).
For the benefit of those in future whose odo gets stuck… I’ll keep going…
When removing the front of the cluster, flip the cluster over and just remove the edge hex screws (Don’t remove those same screws in the body of the cluster!). Then loosen the two bigger screws ether side of the speedo cable post, lower the speedo onto a soft cloth by the post.
Then you can extract the whole thing, you can see here (below) how there are a series of tabs that locate on the odo window in the speedo face. There is one for each register, and it locates so the register turns against this as torque is applied by little internal gears in the preceding register
You can see how my tenths locating tab is bent and mangled as the torque of the tenths drove against all registers . The thin metal inside holding the catch gear was bent.. nothing I could do to make it work, tried lubing etc.
Knowing I had nothing to loose I tried separating the tenths register but no game, so I removed the metal driven gear, put a random mileage just over 50k and put it back in… in due course I will attempt to source a new odo set, but at least the plastic worm gear won’t get chewed out and the speedo won’t jump.
Tonight I just put the cluster and crash pad back in so I can drive it.
You certainly put forth a heroic rescue effort. Sorry it didn’t pan out, but you are now highly skilled at dash pad removal. Looks like a replacement for the standard speedo is available and you can choose one with miles close to 50k I imagine shipping and tariffs will offset the reasonable purchase price though.
Thanks Calicat, i was hoping for repro “classic mustang odometer wheelsets” thinking after 55+ years they would all start failing…. But no dice so far….
