Tomorrow I'm getting the Yukon 4.11 R&P put in the truck's rear end (2wd) at the 4wheelparts in Coppell (they've gota distro center there as well, I might ask for a tour and drool over their inventory. )Anyway, I've read thru a few different posts and never found an answer to my question:

Do you have to reset the Speedo when you swap out gears? And what's the best way to do it?

Any help would be appreciated.

UPDATE:

So they were installed today at 4 Wheel Parts. The service rep said they let the truck idle for 15 miles on the rack to make sure the intial break in was done properly, butI have my doubts as I noticed some noise on the way home.A very soft whirrrrr, is this a whine? I don't think idling with no force put on the R&P is enough and that's why it was noisy on the way home. They told me to take it easy for at least the first 250 miles or so,but should I take it back immediately due to the noise? IsANY noise from a new set of gears acceptable?

I think I'll at least call as a precautionary measure to ensure they know I'm concerned with the noise, and if it doesn't go away shortly I'll be taking it back to them.

On a side note, I can't gauge any acceleration benefits yet as I'm driving extra cautious right now, but it seems to hit the same RPMs about 5 miles an hour sooner right now. It also seems to shift a little sooner. Not 100% sure about that though as I'm really light-footing it right now. I might trya small adjustment of the TV cable to put the shift points back higher if it seems to be a problem. Give me a big, fat, BAD IDEA warning if youall think that's not such a good one to mess with.

 

I did both front & rear on my 2000 but dont remember if I had to redo the speedo or not... I think not, but could be wrong. you will find out when you get it back.

 

I guess it's not the end of the world as I can use the Superchips programmer to set a larger tire size than what I actually have and that should bring the speedo back down.

 

yup, there you go... get a car that has a stock setup & match the speedo's

 

I found this on the web.
http://www.bgsoflex.com/speedo1.html

 

No, you do not need to. On '99 and newer trucks, the speed signal comes off the rear differential tone ring, and is independant of the gears. Only a change in overall wheel/tire diameter requires a speedo recall.

 

And if you want another speedometer gear....
http://www.partshp.com/speedometer_gears.htm#dodge
Don't know anything about them though.......

 

yeah, I found one that was similar at drivetrain direct: http://www.drivetraindirect.com/t_gear_calculator.htm

OK somebody please check my logic here:

Thestock gear ratiois 3.55, OD ratio is .69, stock tires are 29.3"and at 70 MPH the RPMs are 1966. So to make it read like stock I'd need to tell the programmer I was running 34" tires on a 4.11 gear ratio (1962 RPMs , as close as I can get). But since I currently have 30.6" tires I have to add an extra 1.25" to make up the change from stock to account for the new, larger tires and the new gears which would total 35.25", right?

 

You do not need to recalculate for your gears!!!!!!!!!! Read my post up earlier in this thread.

 

Thank goodness, I was starting to doubt my fuzzy math.