Post East Coast Gear Change Results/Feedback

aweaver65

New member
Hi All,

After going through with changing my gears using East Coast Gear assemblies, I thought some of you might want some real world feedback on the results.

Gearing vs. RPM's
1. I went with 4.56 gears, which is roughly a 20% change from the 3.73 stock gears.
2. I never really measured RPM's at completely stock prior to the ICON lift and adding 34's, but my recollection is that at 70 MPH, I was around 2200.
3. RPM at 70 AFTER the ICON and 34" tire install was almost dead on 2000
4. RPM at 70 now, with the 4.56 gears is right at 2400, which seems to be a good spot in the power band. This pretty closely aligns with the % of gear change, which I pretty much expected.

MPG
1. Stock on the highway at 70 MPH was maybe 17 - 18 MPG
2. Post ICON/34's was about the same,
3. Post 4.56's/higher RPM is now around 16.5 but if there are significant Oklahoma head winds, it's 15.5.

So the claims that the regear will help you regain your lost MPG have not turned out to be True for me, BUT the loss is not a big deal either. I suspect that is mostly tied to the way you drive. I tend to drive VERY gently on road precisely so I do not waste gas because I'm not generally in a hurry. Before the gears, I could get up above 19 MPG, but again, that was barely touching the gas. I think if I wasn't so patient, I would have had my foot in it and been eating a lot more gas then.

Final verdict: I love the gears. No more bogging down on the slightest incline, the power band seems to be right where it should be. Do I wish the MPG was a little better, sure. Does it really matter in the day to day? Not really. I figure I will get between 20 and 30 few miles per tank of gas so it will cost me about $4.50 extra per tank. The enhanced drivability is worth that to me.

P.S. on the install, the shop didn't bother to read the manual and learn that they should have placed the stock Diff in Lock with the switch inside the cabin before pulling it so that it would be in phase when the new unit was installed. So they ended up being out of phase and that burnt up an extra 1/2 day of install time for them to sort out. That sucked. Also, I asked the tech about some of the Torque specs, and he didn't seem to remember them, which told me that he pretty much blasted it all together with an air wrench. That made me FURIOUS so I had a chat with the shop owner and had them crack everything they could get to loose and retorque it all. Unbelievable that I had to do that, but it always pays to be thorough.
 
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Is 70 MPH with 4.56 gears what’s indicated on the cluster or the actual speed? I’ve read a couple of post that state 70 MPH on the cluster is actually 75 MPH.
 
East Coast Gears recommended 4.88 for me. I voiced my concern over the recommendation, went with it anyway. and i have some regrets.
I think i would have been happier with 4.56.
I a mall crawler build.. i am fully armored, but no swing out in the back. running 34" and supercharged. At lower speeds and gears, i get a bit of gear hunting before it locks. My speedo has been way off from what actual speed is. Think i am 6-7% over what speedo shows.
 
Is 70 MPH with 4.56 gears what’s indicated on the cluster or the actual speed? I’ve read a couple of post that state 70 MPH on the cluster is actually 75 MPH.
Gears don't affect the 5th gen speedometer. They got rid of the sensor at the transfer case and use the ABS wheel sensors instead. Tire size does affect the speedo...
 
East Coast Gears recommended 4.88 for me. I voiced my concern over the recommendation, went with it anyway. and i have some regrets.
I think i would have been happier with 4.56.
Wish we could trade. I got 4.56 and wish I had done 4.88 instead.
 

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