4.10 Re-gearing - 2025

[CheddarGau]

It appears to be off ~4-5 mph per my phone GPS. 50 is about 54 for example.

I have 265/75/16 (I know we aren’t supposed to go this big, but I did) and now the 4.10 gears.

If it fits, **** it.

 

[Rene_05]

If it fits, **** it.

My oscillating saw and I are well acquainted. Have the washer fluid bottle relocation on my list to further eliminate the rub a dubs.

 

[Rene_05]

Scheduled my 500 mile gear lube change and inspection. The drive has been great, I have a hum/whine under load, 45mph +, which is apparently normal. Yukons apparently usually have some noise.

 

[mercdudecbr600]

It appears to be off ~4-5 mph per my phone GPS. 50 is about 54 for example.

I have 265/75/16 (I know we aren’t supposed to go this big, but I did) and now the 4.10 gears.

my understanding is that the larger diameter tires cause the Speedo to read slow and the 4.10 to read fast.

Though this makes me curious to the accuracy of my new 4.10 setup.

 

[2TALL1]

Have you tried a speedometer app?
Just to see how close you are.

 

[sota]

my understanding is that the larger diameter tires cause the Speedo to read slow and the 4.10 to read fast.

Though this makes me curious to the accuracy of my new 4.10 setup.

GPS is your friend here.
Also that equation depends on the year.
some do speed off a sensor at the transmission (or is it diff?)
others that have 4 channel ABS do it from the ABS sensors.
and some us are screwed and can't adjust it at all, because 07's won't let you.

 

[u2slow]

my understanding is that the larger diameter tires cause the Speedo to read slow and the 4.10 to read fast.

Though this makes me curious to the accuracy of my new 4.10 setup.

Only the tire size matters. Ratio doesn't affect it because the sensor reads from the ring gear, not the driveshaft.

 

[mercdudecbr600]

Only the tire size matters. Ratio doesn't affect it because the sensor reads from the ring gear, not the driveshaft.

off the abs sensor, correct? The early kj have just one abs sensor at the rear diff. No other sensors to my knowledge.

And if that’s true (Speedo not trans dependent) then r/p doesn’t matter and you’ll always read slow with larger tires. Which… seems to correlate with my perceived vehicle speed even after regearing.

 

[u2slow]

off the abs sensor, correct? The early kj have just one abs sensor at the rear diff. No other sensors to my knowledge.

And if that’s true (Speedo not trans dependent) then r/p doesn’t matter and you’ll always read slow with larger tires. Which… seems to correlate with my perceived vehicle speed even after regearing.

Call it what you want. Top sensor on the rear diff.

Our '05 doesn't have ABS. Speedo read fast with stock tires, and now really quite accurate with 30" tires.

 

[Rene_05]

No one wants to recalibrate my speedo for less than $500 so I think it is just going to stay as is for a while. In other news, something is missing in this picture.

 

[sota]

you near NJ and have your PIN?

alternatively, buy (and return! or keep, as it's actually a pretty damn good deal. if I didn't already have an Autel MS906Pro and KM100E it'd have kept it and the key programmer module.) the TopDon UltraDiag. It was able to get into my 07 and change tire sizes correctly, unlike my Autel MS906Pro.

NOTE: on the latter, my software version is "older"... and Autel *claims* their latest update fixes the problem and can reprogram an 07 correctly. No idea if you still need the PIN code to do it with an Autel. The TopDon did *NOT* need the PIN code.

 

[mike]

In other news, something is missing in this picture.

I'll bite. Are the buckets being used as jackstands? I say jackstands are missing.

 

[Rene_05]

I'll bite. Are the buckets being used as jackstands? I say jackstands are missing.

Hehe nah, just holding my brakes. Differential is going back in today.

 

[Rene_05]

you near NJ and have your PIN?

alternatively, buy (and return! or keep, as it's actually a pretty damn good deal. if I didn't already have an Autel MS906Pro and KM100E it'd have kept it and the key programmer module.) the TopDon UltraDiag. It was able to get into my 07 and change tire sizes correctly, unlike my Autel MS906Pro.

NOTE: on the latter, my software version is "older"... and Autel *claims* their latest update fixes the problem and can reprogram an 07 correctly. No idea if you still need the PIN code to do it with an Autel. The TopDon did *NOT* need the PIN code.

Thanks, but I’m in Ohio with aspirations to get further west. Going to have to look into the TopDon.

 

[Rene_05]

Everything is back together. Can confirm the front 4.10 gears I referenced in earlier posts worked, nothing blew up! Would be neat to recalibrate the speedo, but I think I am over it for now .

You must be registered for see images attach

 

[derekj]

Everything is back together. Can confirm the front 4.10 gears I referenced in earlier posts worked, nothing blew up! Would be neat to recalibrate the speedo, but I think I am over it for now .

You must be registered for see images attach

Looks good! What sliders are you running?

 

[Rene_05]

Looks good! What sliders are you running?

Thanks! They are the rocky road supersliders flat. I know lots of folks don’t like them on here, but they fit the way I wanted and are truthfully more for steps. Also didn’t seem like there were any options left. Had them shipped bare and bed lined at a local shop.

If I had found this guy first, I probably would have went with them if price with shipping ended up close. The gentleman that owns the business could check to see if there would be a way for cheaper shipping. I think they actually bolt on, while my RRO ones required drilling and bolting.

Off Road Rock Sliders Heavy Duty JEEP CHEROKEE KJ | AXION PARTS

www.axionparts.store

 

[CheddarGau]

Everything is back together. Can confirm the front 4.10 gears I referenced in earlier posts worked, nothing blew up! Would be neat to recalibrate the speedo, but I think I am over it for now .

You must be registered for see images attach

The school zone speed sign matches my speedy almost exactly, so I didn't bother. Close enough for me. Also what is the height of your lift? Looks good.

 

[Rene_05]

The school zone speed sign matches my speedy almost exactly, so I didn't bother. Close enough for me. Also what is the height of your lift? Looks good.

Makes sense, mine is def off, but shifting seems fine. We’ll see once it makes it to some mountain roads. I’m not sure what the height actually settled at, but it’s the max possible: OME suspension, ATH top plate and three conduit nuts for the strut fork. Two extra isolaters on top of the OME spring in the rear.

 

[Rene_05]

For anyone that cuts the front two differential bolts, below is what I used and they seemed perfect. I originally got 70mm and they were too short for my liking. I got them from advance auto parts and reused the washer and nut. Actually came with a nut, but not the flange type.

Dorman - Pik-a-Nut Cap Screw-Hex Head-Class 10.9- M12-1.75 x 80mm​

Part # 99127080