rear end gears

[tealcobra93]

i have a question I have a 93 cobra with 3.73s now the last owner told me the car now has 82k miles but is more like 62k miles since the 3.73s make the miles go up faster is this true? the lower the gears the faster the miles go up???? I noticed my car miles go up very fast since I use it occasionally and in 4 months im up to 86k miles now what you guys think??

 

[gwiedner]

Just like it makes your speedo read faster than you are really going it throws off the mileage as well. I'm not sure how much but there are formulas out there that tell you how much it will be off with certain gear ratios. The lower your gear ratio (higher the number) the more miles your car will register. You can get new speedo gears to correct it but its not an exact science so it will probably still be a little off.

 

[Mustang5L5]

Why not just buy the $10 speedo gear and fix it??


The difference in gearing is about 14% That means if the gears were installed on Day 1 and you drive 82K miles, you really had about 71K miles. Of course the gears were prob installed later, so you probably have anywhere between 71-82K miles on your car depending on how long ago they were installed.

Buy the right speedo gear. 23 tooth white gear

83-95 SPEEDOMETER DRIVEN GEAR & CLIP KIT, 23 TOOTH, MANUAL TRANSMISSION MUSTANG

 

[tealcobra93]

what if i just disconnect the speedo and ill have 86k no matter how much i drive it would the engine light come on???

 

[Mustang5L5]

No the check engine light will not come on.

 

[FoxChasis]

The 23T driven gear is a POS.

Change the drive gear inside the transmission to 7T or 6T and then get the right driven gear.

 

[old_blue]

no check engine light would come on. it is all mechanical versus copmuter run. even on a sn I think you could unplug it without a check engine light. Just put a new gear in there. take all of 5 minutes to do and you wont get as many tickets