Odometer roll back

[Terry M.]

Re: Odometer roll back

Does the C6 or C7 have a "black box"? If so, I would assume even changing the on board software would not delete the black box info and if it remembers your speed one would expect mileage would also be stored.

The C6 Event Recorder (black box) doesn't quite work like you are describing Richard, but some C6s have On Star and I suspect there is a mileage reading on file with big brother. When I have On Star activated I get a monthly report (via email) of the car's odometer reading, how much oil life remains, and the air pressure in each of the tires -- when the car is not stored that is -- I have to dive the car out of the garage for it to work. That report also indicates any vehicle system malfunctions -- or at least there are spaces for such on the email I get. It also tells me the status of the phone account and how many minutes I have left on the account. The owners manual states that not only can On Star unlock the car doors (in most cases) but it can warn you of maintenance needed and diagnose the "check engine light." I am told if the "check engine light" comes on I can immediately call On Star and they will read the code for me.

I find it amusing to tell unsuspecting people that my car emails me -- and even show them the reports on my mobile device. We have had hints of some of the electronic wonders of the C7 (rev matching to ease shifting for us klutzes), but I have to wonder what else will be hidden in that car. I know all this monitoring makes some people uncomfortable, and some level of it exists in more newer cars than most people think. Let's not get started on the wonders of mobile devices.

[Tom P.]

Re: Odometer roll back

"Back in the day", when we knew that a particular car would not be kept very long, we simply disconnected the speedo cable, either from the back of the speedometer or from the tranny-------------------------TOOOOOOOOOOOOOOO EASY!!!!!!!!!!
Then connected it back when the car was traded or sold.

[Dan D.]

Re: Odometer roll back

In NYS odometer readings are sent to Albany (state DMV) as part of the annual inspection process. For cars built before 2001 mileage was hand written on a form, but I don't know how it was transmitted. For post 2001 cars mileage is transmitted electronically, along with the emissions data and whatever else.

But I don't know what Albany does with this information. Is it compared to previous years data, or just go on file with other useless data?

Any of the cars I have observed in car lots or for sale have high mileage: 20 -30k per year. Most cars are well used these days - in spite of the cost of gas or lease requirements. I thought it was all but impossible to alter the newer electronic speedometers, but I probably should have known better. -Dan-

[Stuart C.]

Re: Odometer roll back

Has not been many years ago when you could pull a fuse on Fords and stop the speedometer.

yea but now the speedometer is tied to a lot of computer functions that run the car so if you disconnect the speedo it screws up how the car runs

[Ken A.]

Re: Odometer roll back

Well, not exactly that cheap. But at .35 cents a mile for mileage penalties on a lease, the break-even is 7,714 miles.

THIS HAS BEeN A VERY ENLIGHTENING THREAD FOR ME. I had no idea these devices were so readily available. Based on what I've taught myself today, I will never trust the odometer reading on any car ever again. Take an operation like Carmax. If John Corazine wasn't prosecuted for the theft of a Billion or so in the MF Global deal, why should a penny-ante operation like a used car dealer worry about a few rolled odometers? "Nobody committed any crimes".... F!

This stuff on the internet is for suckers. A real pro would not use them. Only the cluster is altered, the real mileage is still there (in at least 5 or 6 other modules) & can be easily accessed with the right equipment.

[Jim T.]

Re: Odometer roll back

In 1974 my bought new 1970's speedometer stopped updating the mileage and the speed indicator still worked. Knowing I had about a year left on the 50,000 mile warranty I replaced the complete speedometer unit right away, new one what white numbers. Total mileage on my 70 now with the combined speedometer mileage is now over 160K.
I don't know of any way the next owner would know the replacement has turned over 100,000 without stating the facts. I have since replaced the white numbered speed indicator using the 70's original green colored speed indicator piece.

Do not know how many C3's are configured like my 1970 turbo 400. The speedometer cable from the transmission is a two piece unit that could be easily separated near the firewall under the car. Did the 4-speed C3's come configured this way? My 68 4-speed is not.

I did have warranty work on my 1970 before the 50,000 warranty expired after the original speedometer mileage failed. I took the original speedometer and the invoice of purchase of the new speedometer to the Chevrolet dealer for verification of mileage.

[Dick W.]

Re: Odometer roll back

yea but now the speedometer is tied to a lot of computer functions that run the car so if you disconnect the speedo it screws up how the car runs

On those models the only thing you lost was speedo and power windows. Don't ask me how I know

[Kenneth B.]

Re: Odometer roll back

"Back in the day", when we knew that a particular car would not be kept very long, we simply disconnected the speedo cable, either from the back of the speedometer or from the tranny-------------------------TOOOOOOOOOOOOOOO EASY!!!!!!!!!!
Then connected it back when the car was traded or sold.

BINGO It took 2 minutes to unhook the spedo. cable. All of us did it in the 60's because of the warrenty. The miles ran out way before the time even though alot of them were a 1/4 MI. at a time.

[John H.]

Re: Odometer roll back

In NYS odometer readings are sent to Albany (state DMV) as part of the annual inspection process.
But I don't know what Albany does with this information. Is it compared to previous years data, or just go on file with other useless data?

Wait until New York starts assessing road tax based on annual miles traveled (instead of via gasoline taxes as consumption by cars begins to diminish) and you'll know exactly what they plan to do with the annual mileage information.

[Dick W.]

Re: Odometer roll back

BINGO It took 2 minutes to unhook the spedo. cable. All of us did it in the 60's because of the warrenty. The miles ran out way before the time even though alot of them were a 1/4 MI. at a time.

Would buy at least one new car a year. Odometer never would show 5,000 miles. Until 1970 I was buying new cars at dealer cost, would retail the used car, and not cost over $200 to drive a new car.

[Brian M.]

Re: Odometer roll back

The 1996 Impala had that feature.

Has not been many years ago when you could pull a fuse on Fords and stop the speedometer.

[Joe C.]

Re: Odometer roll back

C4 Corvettes, and probably all other cars of the era use a thin mylar tie-bar instead of the old inking. The tie-bar is perforated in 5 places, attaches a lug on each of the tumbler drums, and keeps all of the tumbler drums aligned. If the odo is run backwards, the mylar tie-bar breaks and the tumblers become misaligned, resulting in the numbers in total disarray.

I don't see how it's possible to tamper with a C4 odo, including R & R in under an hour.

[Dick W.]

Re: Odometer roll back

C4 Corvettes, and probably all other cars of the era use a thin mylar tie-bar instead of the old inking. The tie-bar is perforated in 5 places, attaches a lug on each of the tumbler drums, and keeps all of the tumbler drums aligned. If the odo is run backwards, the mylar tie-bar breaks and the tumblers become misaligned, resulting in the numbers in total disarray.

I don't see how it's possible to tamper with a C4 odo, including R & R in under an hour.

There is a similar tie bar on your mid year. You can take the needle type tools I referenced and manipulate the numbers on the drum. There used to be many masters that could do this before you blinked your eyes. I saw a set of those needles a few months ago. If I can run up with the guy that owns them, I will make a photo and post it.

[Joe C.]

Re: Odometer roll back

There is a similar tie bar on your mid year. You can take the needle type tools I referenced and manipulate the numbers on the drum. There used to be many masters that could do this before you blinked your eyes. I saw a set of those needles a few months ago. If I can run up with the guy that owns them, I will make a photo and post it.

That's interesting about the needle tools. Probably have to push the drum off to the side to disengage its teeth from the teeth on the wheels in between before turning the drum back. Tricky but "trick"!
I remember a couple local joints where car flippers would bring odos to have them "hit". Both in a back room of small carb, alternator, generator rebuilders or electrical experts/short finders.
I've done a few on midyear and shark restorations. I "know someone" very well who has done a few flat dash C4's.

[Richard S.]

Re: Odometer roll back

C4 Corvettes, and probably all other cars of the era use a thin mylar tie-bar instead of the old inking. The tie-bar is perforated in 5 places, attaches a lug on each of the tumbler drums, and keeps all of the tumbler drums aligned. If the odo is run backwards, the mylar tie-bar breaks and the tumblers become misaligned, resulting in the numbers in total disarray.

I don't see how it's possible to tamper with a C4 odo, including R & R in under an hour.

As I recall the C4's tie-bar was attached to plastic lugs which could be softened with a soldering iron and then reattached after the tumbler drum was adjusted.