Calibrate speedomiter

[redneck]

Well I finally got my gears and tires installed 5.29 and 33x10.50 bfg muds, now how do I get my speedo to read corectly.

[mjflatbed]

What I have found to work o.k. is to go out on a straight piece of the Interstate and mark your odometer reading down as closely as possible when you cross a mile marker. then cover 10 miles by mile marker and note your odometer reading. You should beable to then go to the dealer and tell them how far off it is and get a different gear for the speedo cable. If not you will then know how far off you are as a percentage which can keep you know how close to speed and distance you rally are going.

10 miles by markers
odometer is 9.5 miles
you would be 5% slow

Odometer is 8 miles
you would be 20% slow

Odometer is 11 miles
you would be 10% fast

Hope this makes sense and helps???

[JOKER]

When I put 33's on my truck that has 5.29's, I had to drive 5 mph over the speed limit to be able to drive the speed limit.

Another way to fix it is to put 35" or 36" tires on and your all good.

[4xtoy]

Well I finally got my gears and tires installed 5.29 and 33x10.50 bfg muds, now how do I get my speedo to read corectly.

33's and 5.29's sounds pretty low geared to me, but anyway check your phone book for a speedmeter shop. We have two here and for about $50 they will put it on a dyno and calibrate it perfectly. You could also call a tranny shop and ask them who you can take it to. Just be sure you plan to keep gears and tires the same for a while. What I do right now is just use my RPM's to determine my speed. Have someone go with you on the highway in another vehicle and run next to you at a chosen speed. take note of what gear and RPM you are running and note that as "x" mph. Do this with a couple of common crusing speeds.
example:
2800 rpms in 5th gear (or overdrive for auto's)=65mph etc...

[naloboy]

Ive found that the easiest way to recalibrate is to know your new gear and tire size then go contact Downey ( I think its Downey that sells them ) They have premade speedo cables based on tire size and gear ratio