Rear Gear Swap Questions...

[Dan Acosta]

I have an 05. I currently have a 3.73, and would like to swap it out to something a little lower like a 4:10 for towing.

Can someone recommend a gear and or supplier

Is there a list of known vehicles that would have a had a similar gear from the factory - like a junkyard find list?

 

[Forrest0125]

I have an 05. I currently have a 3.73, and would like to swap it out to something a little lower like a 4:10 for towing.

Can someone recommend a gear and or supplier

Is there a list of known vehicles that would have a had a similar gear from the factory - like a junkyard find list?

I have an 05. I currently have a 3.73, and would like to swap it out to something a little lower like a 4:10 for towing.

Can someone recommend a gear and or supplier

Is there a list of known vehicles that would have a had a similar gear from the factory - like a junkyard find list?

Dont know if theres a list but your best bet would be a 1/4 ton pickup or maybe a burb if sourcing junkyard gears. As for supplier ive never had a set fail on me, motives seem to get praised for being quieter. Richmond yukon AAM all make sound parts. Ive only used G2 once in a jk but had no compliants, just not gonna talk highly of something i only used once. Keep in mind the 10 bolt came in 4 sizes with the 8.5" and 8.6" being the only 2 i would trust with 4.10s.

 

[swathdiver]

I have an 05. I currently have a 3.73, and would like to swap it out to something a little lower like a 4:10 for towing.

Can someone recommend a gear and or supplier

Is there a list of known vehicles that would have a had a similar gear from the factory - like a junkyard find list?

Find a similar year 2000-2004 4WD Taho/Yukon with RPO GT5 for the 4.10s or a 2000-2006 Suburban with the 4.10 GT5 RPO. Buy the whole rear and swap it out. I hear lots of folks speak highly of Yukon Gear for axle parts. Lots of options, more will chime in.

 

[01ssreda4]

Swap in a motive 4.10 in your current rear end. Will definitely help towing.

 

[Dan Acosta]

Good information, How much of a change in rpm should I expect with the 4.10 vs. the 3.73? I am thinking it wont be a huge difference.
Also, I dont think the gear lube has been changed (140k miles). Any suggestions for a "towing" gear lube? I am going to use synthetic, I dont if I should change viscosity and or if there is a lube that is superior like Purple, or Lucas?

 

[swathdiver]

Good information, How much of a change in rpm should I expect with the 4.10 vs. the 3.73? I am thinking it wont be a huge difference.
Also, I dont think the gear lube has been changed (140k miles). Any suggestions for a "towing" gear lube? I am going to use synthetic, I dont if I should change viscosity and or if there is a lube that is superior like Purple, or Lucas?

Assuming a 265-70-17 tire, the 3.73s @ 70 will turn the motor 1933 rpms and around 2125 @ 70 with 4.10s.

Stick with stock weight lubricant. Mine own preference is factory fluids but those are fine too.

 

[Dan Acosta]

Assuming a 265-70-17 tire, the 3.73s @ 70 will turn the motor 1933 rpms and around 2125 @ 70 with 4.10s.

Stick with stock weight lubricant. Mine own preference is factory fluids but those are fine too.

Thanks, just what I was looking for!

 

[Dan Acosta]

Thanks, just what I was looking for!

Assuming a 265-70-17 tire, the 3.73s @ 70 will turn the motor 1933 rpms and around 2125 @ 70 with 4.10s.

Stick with stock weight lubricant. Mine own preference is factory fluids but those are fine too.

BTW, do you use a online calcualtor for that (RPM)? I have 275.55.20 tire but the size is marginal.

 

[Scottydoggs]

in a perfect world you'd want to have the gear change done in your tune. black bear time......

 

[swathdiver]

BTW, do you use a online calcualtor for that (RPM)? I have 275.55.20 tire but the size is marginal.

No, I made a calculator with Excel. Even down to tread depth! That tire is slightly tall so you're RPMs would be about Eighteen less in each case. About 1915 @ 70 mph with the 3.73 gear. 2106 with the 4.10. Probably not even noticeable!

Another way to look a the gear swap, with the 3.73 @ 2000 rpms your running 73 mph. With 4.10s @ 2000 rpms your running 67 mph. These are mathematical formulas without consideration for slippage.