robgarner

Okay its 5degrees this morning and my speedometer needle went from 30mph to 120 and the speed warning horn came on. i pulled over and so cold that the hood wouldnt open. the noise went away and i kept driving. Got on the hwy and was doing 75mph and the speedometer needle was bouncing around a bit and outta nowhere again the needle goes to 120 and the horn comes on again. After about 30 seconds it went back to normal.

Transmission was rebuilt maybe 2 years ago with maybe 20k miles on it. I've read different threads about this but no issues similar to mines. Any direction would be good before i go taking the dash apart.

Thanks

MDchanic

It's cold. Oil is thick and stuff is sticking.

See if it does it when it's warmer.

- Eric

robgarner

Thanks I'll keep you posted. I beleive you helped me before when i had a major backfire problem on my 455. Anyhoo i eneded up replacing the motor with a rebuilt 425. Its my daily driver. I commend you on your advice on these threads. Thanks again and i'll keep you updated because its supposed to get up to around 43 tomorrow and saturday.

Thanks again.

oldcutlass

The cable is probably binding as the temps are cold. When it gets warmer you might try pulling the cable out of the sleeve, clean and lube.

MDchanic

Just to clarify: It sounds like the problem is occurring because of the cold, but that doesn't mean it is supposed to happen in the cold.

I have had a few cars over the years where the speedo behaved erratically when it was very cold out, but then smoothed out when it got warm. I never worried about it.

On the other hand, the coldest day I drove my '68 Delta 455 "back in the day" was -25°F, where I had to keep scraping the ice off the inside of the windshield until the heat finally warmed up, and everything in that car, including the speedo, worked flawlessly in the cold.

- Eric

jaunty75

This has nothing to do with the transmission. I had the same issue with my '73 Custom Cruiser. It's the fact that it's very cold and the lubricant in the speedometer cable is old and probably drying or dried out. As oldcutlass suggests, the permanent fix is to lubricate the cable.

My solution was to move to a part of the country where it doesn't get that cold.

robgarner

LOL thanks and it hasn't happened since but it was colder than 5degrees and it didn't happen. I'll lubricate the cable when it warms up.