Technical I'm having speedo reduction issues

Ordered a spedo correction box for my 53 chevy.. After waiting 2 months to receive it it is off by 40 mph. They say no refund an special order an it is not made to the proper reduction that I requested .Just wana keep anyone else from getting the shaft like I did ..

 

How is it off by 40mph? You doing 5 and it says 45?

 

40 mph off..... I wonder if there was a mistake on weather it was "plus or minus' as far as percentage of correction.

they are ordered by percent of overdriven or underdriven; like "121%" or whatever.

 

I have ordered many parts from Jim Carters Truck Parts in the past,,everthing was A-OK..I do not think Jim carter was the manufacturer of the part you ordered,so why are you blaming him???
Is it possible that you ordered it wrong??? since you mention it was a "special order"

 

It was made by metro speedometer it was suppose to be 57% reduction but they made it 43% reduction an say they won't redo it.. But purchased thru Jim Carter..

 

It is off by a percentage. What information did they ask you for? I used to build those box's and it takes about ten minutes. Don't be to quick to judge. For it to be that far off you may have given them some bad info.

 

They asked for spedo reading at 60mph.. I gave them that and I figured the reduction ratio an included it. When I got it I knew it wasn't gona be correct because I turned it by hand an you could see there was not enough reduction.An after instalation I was right..

 

"it was suppose to be 57% reduction but they made it 43% reduction"


something does not sound right, if you really mean it is off by 40-MPH.

You say their error is 14% less in reduction. How could a 14% re-correction fix a 40-mph error?

 

I've known Jimmy Carter for 20 years and never found him to be anything but a helpful gentleman.

 

My spedo was reading 142 at 60 so it needs 57% reduction they gave 43% that puts it reading about 102 at 60...

 

Sounds like it is reading in Km an hour now!

 

See what it reads at 35mph. Seriously it may be a metric converter

 

I have a few of those boxes that I got from the junkyard, mostly on used transmissions, years ago. I swap gears around in them to make them do what I want.

Just curious...how accurate is your odometer?

 

something's off a bit
the 1st result would be 61...close enuff to 60
but..
the 2nd reduction of 43% is right at 81, not 102

simple way to do these percentages is just type them in as you'd say it in Google
i.e.
142 minus 43% =

no need to crank up a calculator, and this is useful for a number of math problems

 

Metric is easy to convert mph to kmph
Multiply mph by 1.61 to get kmph

 

Just a thought, maybe the internal gears are **** about face and could be swapped to opposite sides, this may correct error?

 

142 x 43% = 61.06 142 x 57% = 80.94.. ???

 

I'm lucky to live in a city that has a speedometer shop. They have the components and make them on site.

 

I do not have a dog in this fight.....however I agree that something is not right in this story and bad mouthing a vendor before you have accurately solved the problems seems unfair.

May I suggest you change your thread ***le to something more in the form of a question than an accusation. For instance....."Need help figuring speedometer correction"

You might also want to provide more specifics........the make and model of the speedo, the type of transmission, rear end ratio, tire size......

Ray

 

How did you get the 60 mph? Did you follow someone with a known to be accurate speedo?

Every speedo turns 1,000 times per mile. I had a stand alone speedo that read in thousandths that I could plug the cable into and then we had a measured mile that we could start and stop and read the speedo and see what we got.

With that info and a chart I could build the box. It is possible that the box may have the right gears but as stated above it may have been ***embled wrong. Try opening it and swap the gears. The known speedo may not have been correct.

When I did this long distance I would tell them to stop at a mile marker sign, read the odometer, drive to the next sign and read it again. With their best estimate tell me how far off the odometer was. I could usually get within three to five percent.

Keep in mind that older gear drive speedos were not that accurate. Fords were around 4%, Chevy was 6-10% and I had a Dodge that was stock and 13% off.

I thing a little more investigation is in order before the accusations start flying.

 

Hmm, 57+43 = 100. Gear swap.

 

And after you figure out how far off the odometer is, you might be able to play with the gears in the transmission to get it pretty close.

 

Yes that was what I was trying to avoid with the adapter but looks like that's the way I will address it now.. Just wish I had done that before I got took for 100$..But lesson learned they won't burn me again....

 

I know you're disheartened, but I think you need to re-read the suggestions and posts in this thread. There are lots of things to try and it does seem odd that a well known supplier will only say, "no backsies".

 

Sounds like there was mix up in the terms being used.
43% of 142=61.06
142 - 57% =61.06

 

His website says to use 50 mph not 60 mph. 142 at 60 would be about 118.33 at 50. 57% of 118.33 =67.44 mph reduction. 118-67.44 = 50.56 mph. Unless I'm missing something, it sounds to me that you're the one who made the error.

 

Here's what you do. Use the app on your smart phone. At, say 25 mph see what your speedo says. Do it at another speed say 60. Same thing see what the speedo says. Give this info to the speedo shop and let them figure it out. Then if its wrong you have a foot to stand on.

 

Can always sell it, sure there are other rodders out there looking for that ratio

 

Used to build these all the time.. if the correct numbers are given its simply looking at the ratio gear chart and building the adapter.. 15-20 mins. If the info given is wrong the ratio will be wrong.. or if the ***embler reads the chart wrong or puts the gears together in the wrong position it will be wrong. They are super simple to re gear and any old time speedo or truck shop should be able to correct it if its built wrong.

 

Sounds to me your issue was self inflicted