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2006 avalanche differential question


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pancho1
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Aug 15, 2012, 12:11 PM

Post #1 of 11 (1600 views)
2006 avalanche differential question Sign In

I have a 06 avalanche 5.3L engine, with a 6 in. lift and 33 in. tires, my ? is this, it feels very sluggish and wastes a lot of gas. I thought it was the lift and tires, but a buddy told me it is the differential because he claims it has towing gears, which makes it sluggish and waste gas. Is there any truth to this? And if so what do I do to put "normal" gears in it?


Tom Greenleaf
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Aug 15, 2012, 12:20 PM

Post #2 of 11 (1592 views)
Re: 2006 avalanche differential question Sign In

Crazy 33 inch wheels or tires way to large is going to register fewer miles, make it feel like it's in a higher gear and just messed the whole thing up IMO. That would have to be so meticulously altered to behave like anything more than a half sunken canoe I'm not the least bit surprised,

T



pancho1
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Aug 15, 2012, 12:25 PM

Post #3 of 11 (1588 views)
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So can anything b done? What would u suggest? Thanks Tom


Hammer Time
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Aug 15, 2012, 12:30 PM

Post #4 of 11 (1582 views)
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When you mess with the engineering, things happen. As Tom pointed out, the tires are too tall which geared it way too high and took all the power away. It also messed up your speedometer.



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pancho1
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Aug 15, 2012, 12:31 PM

Post #5 of 11 (1573 views)
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In Reply To
When you mess with the engineering, things happen. As Tom pointed out, the tires are too tall which geared it way too high and took all the power away. It also messed up your speedometer. Should I take off the lift and tires? Will that help?



Tom Greenleaf
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Aug 15, 2012, 12:36 PM

Post #6 of 11 (1561 views)
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Once, you could get a gear driven speedometer/odometer to match it all up but I doubt it for this. Unless the purpose was to show it I really think the thing to do is undo all that if you really like what is left after the carnage.

Yes - Much older trucks had pre-engineered lift kits. Where I live NONE would be allowed on public roads,

T



nickwarner
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Aug 15, 2012, 3:11 PM

Post #7 of 11 (1538 views)
Re: 2006 avalanche differential question Sign In

You can get an aftermarket programmer that, among other things will allow you to adjust your computer for different tire sizes, gear ratios, etc. Your buddy that talks about normal gears and towing gears has no idea what he is talking about. Some models are offered with a tow package that includes a lower gear ratio. For instance, my Suburban was offerered with 3.42 or 3.73 gears. I have the 3.73 gears which make it quicker off the line but results in higher RPMs versus the 3.42 option. Were you to put in diffs with a smaller ratio you would have even worse problems and would likely burn up your trans in short order. Depending on what your tire size was from factory the 33 inch might not be that huge a leap. I did the math on mine and the standard to metric conversion worked out to 32.43 inch diameter stock. I'm guessing yours were closer to 30, but post the tire size and what your current axle ratio is and we can go from there.


Hammer Time
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Aug 15, 2012, 3:19 PM

Post #8 of 11 (1531 views)
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Quote
You can get an aftermarket programmer that, among other things will allow you to adjust your computer for different tire sizes, gear ratios, etc.


Let me clarify what Nick is saying. You can correct the speedometer, timing, shift points and a few things like that with software mods but you cannot get back the power you lost due to tire size changes. The mechanical gear ratio is permanently changed and the engine may not have the horsepower to overcome the increased load.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



nickwarner
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Aug 15, 2012, 4:43 PM

Post #9 of 11 (1518 views)
Re: 2006 avalanche differential question Sign In

Thanks for the clarification HT. The only way to make this truck move at a rate of acceleration close to stock is to match the gear ratio and tire sizes to a desired engine RPM at a given speed. The engineers at GM did that for you when they built this truck. Now you deviated from the original design and it doesn't act like a stock truck would. It won't because it wasn't designed in that configuration. So now we need to know what gears it has and the stock sized tires to come up with a gear ratio that you would need to restore that balance. Even then, remember this isn't going to handle like a shock truck since its lifted. But a lower gear ratio will take stress off the transmission and engine. It just needs to be properly matched.


Hammer Time
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Aug 15, 2012, 4:45 PM

Post #10 of 11 (1516 views)
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Let me add that the wear and tear on your suspension, wheel bearings and steering will be about triple what it would have been now.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Aug 15, 2012, 4:46 PM)


nickwarner
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Aug 15, 2012, 5:26 PM

Post #11 of 11 (1509 views)
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Indeed, the extra weight of the rotational assemblies, the steeper angles on both driveline and suspension, and in general the way a vehicle built to go off road tends to be driven all combine into something expensive to maintain. Parts are available from various vendors other than parts stores that will take heavier abuse, but I assure you they will cost significantly higher than stock.






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