Does anyone know if this would mess up the transmission or computer anything related? I think this would improve the gas mileage tremendously. I only pull a 2500 lbs. trailer on occasion, and a 308 or a 342 would work ok. Any comments from you gearheads?
2006-06-13 17:20:21 · 5 answers · asked by randyrich 5 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
In 2003 gm installed 2 trans in the avalanche ,the 4l60e and the 4l80e. Either way the final ratio in overdrive nets 30%. which means that at 60 mph your engine rpm will be around 2000. changing to a higher ratio gear will create more problems than the amount of fuel you hope to save.Your avalanche will have no power and will more than likely be down shifting more often because of the higher throttle position.in turn means more fuel consumed.The speed sensor is located in the diff and the ECM is calibrated to a specific ratio along with that the abs sensors are located in each of the hub positions and sence wheel movement so you should not have a problem there. My suggestion is to leave it alone ,the truck is engineered to do a specific job and any modification (major) only creates a snowball affect..The truck is engineered to run at a certain RPM at cruise speeds lowering that RPM is going to cause the truck to lug and in turn is going to cause you to want to accelerate harder.. GM has never used a 3.08:1 ratio behind any o/d trans for this reason.. The engine is just not turning hard enough at cruising speeds.
2006-06-16 12:34:37 · answer #1 · answered by thinkinoutloud 2 · 1⤊ 0⤋
You will have to switch the front too, assuming 4wd. You can buy ring and pinion sets and have them installed, but this is a job for either a professional or a high difficulty level DIY job. They may also be hard to find especially for the front diff because it would be uncommon to swap to a higher gear, and if they are available they will probably be expensive because of the low demand.
The change would not net much better mileage if any. the engine and tranny with o/d (assuming a 4l60E) are built to keep the engine at it's optimal efficiency. changing the gears without recalibration of the computer may cause the fuel and spark curves to run where they are less efficient because the load will seem greater than it would have been had the gears been lower.
you would get the same effect from a taller tire...
If you want mileage might look at another vehicle, pushing a 6k lb.+ vehicle shaped like a box will ever be economical.
2006-06-13 17:35:57 · answer #2 · answered by JetboyToy 3 · 0⤊ 0⤋
Being an Avalanche question, I would suggest you ask the experts who know this truck just about as well (sometimes even better) as the people who design and build it.
If you post this question at the forum (http://www.chevyavalanchefanclub.com/cafcna/index.php/board,109.0.html) I'm sure the gear-heads there will have an accurate answer for you in no time.
We are a organization of more than 10,000 members world wide and the knowledge base is incredible.
Come on over and sign up for free at http://www.chevyavalanchefanclub.com and tell them that The_Wifes_AV sent you.
2006-06-15 04:15:04 · answer #3 · answered by M A 1 · 0⤊ 0⤋
You will have to have your tranny readjusted because of the new ratio at the rear wheels and also the ABS system will need to be recalibrated. Both of which can be done at Transmission shop worth their salt. As far as changing the axle itself all you have is four "U"-bolt and and the drive shaft to remove. By the way you MOST change the front axle to the same ratio as the rear(if it is the 4X4 model )
2006-06-14 16:01:23 · answer #4 · answered by WolfMan 1 · 0⤊ 0⤋
I think it wouldnt be a good idea. Just drive slower.
2006-06-13 17:26:02 · answer #5 · answered by repo2agent 3 · 0⤊ 0⤋