Rear End Gear Ratio and Towing
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Rear End Gear Ratio and Towing
Hello All, New guy here.
I've been looking at tow vehicles for a while now (want to tow my Track Car to the track) and the Durango and it's 7400lb capacity caught my eye recently. During my research, I was perusing the Ram website and noticed that a lot of the Ram's towing capacity was dictated by the rear end gear ratio. I know the 3rd Gen's haven't been around all that long, but has anyone tried swapping in a lower gear ratio to improve towing capacity? Would the Ram's optional 3.55 or 3.92 final drive fit? While I don't know it for a fact, one might think that the rear end in the Durango might be quite similar (if not identical) to what's in the Ram.
Thanks for the input!
I've been looking at tow vehicles for a while now (want to tow my Track Car to the track) and the Durango and it's 7400lb capacity caught my eye recently. During my research, I was perusing the Ram website and noticed that a lot of the Ram's towing capacity was dictated by the rear end gear ratio. I know the 3rd Gen's haven't been around all that long, but has anyone tried swapping in a lower gear ratio to improve towing capacity? Would the Ram's optional 3.55 or 3.92 final drive fit? While I don't know it for a fact, one might think that the rear end in the Durango might be quite similar (if not identical) to what's in the Ram.
Thanks for the input!
THE ULTI-MOD
Joined: Jan 2007
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From: Union NJ
the Durango comes with the 3.06 or 3.47 rear end gears in the newer model. The higher number will equate to better towing (steeper gears as it is referred to).
that said the new durangos have independent rear suspension iirc, which is a completely different setup than the solid rear axle that the RAM uses.
the 7400lb towing capacity is the 2wd models, w/ the 5.7l V8 and steeper gears with the factory installed tow package (this usually includes hitch, wiring, trans cooler, larger folding side view mirrors). you can very easily upgrade the gears even more however as the gear ratio goes up you will get better acceleration with (and without) a load on the trailer, you will eventually (likely very quickly) hit a limit where the brakes arent up to the job of stopping the load, and the lack of weight in the truck causes a decrease in stability on the highway (being passed by large vehicles)
that said the new durangos have independent rear suspension iirc, which is a completely different setup than the solid rear axle that the RAM uses.
the 7400lb towing capacity is the 2wd models, w/ the 5.7l V8 and steeper gears with the factory installed tow package (this usually includes hitch, wiring, trans cooler, larger folding side view mirrors). you can very easily upgrade the gears even more however as the gear ratio goes up you will get better acceleration with (and without) a load on the trailer, you will eventually (likely very quickly) hit a limit where the brakes arent up to the job of stopping the load, and the lack of weight in the truck causes a decrease in stability on the highway (being passed by large vehicles)
Last edited by shrpshtr325; Jun 29, 2012 at 03:32 PM.
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. . . but has anyone tried swapping in a lower gear ratio to improve towing capacity? Would the Ram's optional 3.55 or 3.92 final drive fit? While I don't know it for a fact, one might think that the rear end in the Durango might be quite similar (if not identical) to what's in the Ram.
I just happened to be changing oil today and was looking around while the Durango was up on ramps. There is NO WAY I would attempt to disassemble these differentials. They are castings with multiple attachments, on both side of the gear case. It would require A LOT time to dis-assemble and reassemble.
I have set-up ring-and-pinion gears in numerous Jeeps (solid axle), but would never attempt changing these. If you have a shop do it, I would expect a fairly high labor expense.
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