I Want New Gears I Think

beav626 · June 22, 2009

My 01 with the 4.8L feels like a wimp cruising on the highway with 22" Rims. I struggle going up any kind of hill. Now that summer is here and I will be towing my boat, I'm afraid I wont have the power I need to pull my boat up a hill.

I have the 3.15 diff and was considering going to a 3.73

Who has done this and what you recommend. Should I just change out the gears or swap the pumpkin? I am trying to be as cost effective as possible. would engine mods be a better choice?

Matt_ · June 22, 2009

You should consider going with 4.10s, especially if you're towing with the 4.8L.

I'm assuming you've never done gears by the questions you have asked... are you planning on having someone help you? Is your truck 2WD?

If you find a rear with 3.73s or 4.10s in it, you can change it out in an hour or two and just need to reprogram the computer. If you're just going to buy a ring&pinion and a master install kit, you're going to want a professional to install them for you. They're not incredibly "hard" to do, if you know what you're doing and have the right tools...

beav626 · June 22, 2009

You should consider going with 4.10s, especially if you're towing with the 4.8L.

I'm assuming you've never done gears by the questions you have asked... are you planning on having someone help you? Is your truck 2WD?

If you find a rear with 3.73s or 4.10s in it, you can change it out in an hour or two and just need to reprogram the computer. If you're just going to buy a ring&pinion and a master install kit, you're going to want a professional to install them for you. They're not incredibly "hard" to do, if you know what you're doing and have the right tools...

I made a mistake-I have code GU6 3.42 Rear... it is a 2WD truck.

I have never done gears but have friends that have swapped out pumpkins.

Will a 4.10 be enough of a gear change to pull my truck w/ 22"s and a 2500 pound boat without any issues?

jrrod2004 · June 22, 2009

You should consider going with 4.10s, especially if you're towing with the 4.8L.

I'm assuming you've never done gears by the questions you have asked... are you planning on having someone help you? Is your truck 2WD?

If you find a rear with 3.73s or 4.10s in it, you can change it out in an hour or two and just need to reprogram the computer. If you're just going to buy a ring&pinion and a master install kit, you're going to want a professional to install them for you. They're not incredibly "hard" to do, if you know what you're doing and have the right tools...

I made a mistake-I have code GU6 3.42 Rear... it is a 2WD truck.

I have never done gears but have friends that have swapped out pumpkins.

Will a 4.10 be enough of a gear change to pull my truck w/ 22"s and a 2500 pound boat without any issues?

yep, that should put the engine in the power band range for towing. What did the truck originally come with in regards to OEM rims?

beav626 · June 22, 2009

the 16" Aluminum rims

jrrod2004 · June 22, 2009

the 16" Aluminum rims

Hmmm, those 22"s may weigh 15-25 Lbs more than those stock 16" aluminums. Even though, with the swap to 4.10s would help out with towing but it will hurt your top end (Engine speed as well as top speed) a little.

beav626 · June 22, 2009

the 16" Aluminum rims

Hmmm, those 22"s may weigh 15-25 Lbs more than those stock 16" aluminums. Even though, with the swap to 4.10s would help out with towing but it will hurt your top end (Engine speed as well as top speed) a little.

I was considering getting some 20"s but didn't think the weight savings would be worth it.

Would 20's weigh that much less than 22's

jrrod2004 · June 22, 2009

the 16" Aluminum rims

Hmmm, those 22"s may weigh 15-25 Lbs more than those stock 16" aluminums. Even though, with the swap to 4.10s would help out with towing but it will hurt your top end (Engine speed as well as top speed) a little.

I was considering getting some 20"s but didn't think the weight savings would be worth it.

Would 20's weigh that much less than 22's

Not much per Rim, and certainly not worth the difference in cost (unless you recoup it by selling the 22"s). Perhaps with the money instead, you could add some performance mods but with your current setup, I would regear the pumpkin out back and then have the PCM retuned to change that value as well as perhaps tuning the rest of the truck (if you dont already have a tune).

beav626 · June 23, 2009

so what is the best and least expensive way to get a set of 4.10 gears on my truck.

Matt_ · June 23, 2009

Yeah i would definitely get those 4.10s in there, you'll probably be good with your current wheels/tires and towing a 2500lb boat

The 3.42's with the 4 speed trans coupled with the 4.8L is just not meant for hauling anything (as you've found out)... put those 4.10s in there to get the 4.8 into the powerband, and with the proper tune it'll be a whole different truck

Matt_ · June 23, 2009

so what is the best and least expensive way to get a set of 4.10 gears on my truck.

i'd call around for some install prices and go from there. You could try finding axles from a junk yard but then you have to worry about rebuilding it if there's water sitting in the case.

Since you only need to gear one axle, it'll probably be between $500-$700 (though this varies A LOT by location)

Bowler807 · June 23, 2009

More than the weight of the wheels, the diameter of the tires will affect the gearing more. You can have your 22 inch wheels and if the tire diameter is the same as stock you will notice little difference in performance. If however your tire diameter is larger, now the tire has to travel farther per revolution thus reducing the gearing. For example if your stock tires were 32 inches in diameter with 3.42 gears in 3rd gear without lock-up at 65 mph your RPM's would be roughly 2334. With everything else the same just changing the tire diameter to 35 inches your RPM's at 65 mph would be 2134. This is almost a 9% difference in RPM's. To get back to the stock RPM with the 35 inch tires 3.73 gears would need to be installed.

Check out this site. It has a matrix of tire size vs gear ratio. http://www.4lo.com/calc/geartable.htm

beav626 · June 23, 2009

Great Information... Thanks

jrrod2004 · June 23, 2009

More than the weight of the wheels, the diameter of the tires will affect the gearing more. You can have your 22 inch wheels and if the tire diameter is the same as stock you will notice little difference in performance. If however your tire diameter is larger, now the tire has to travel farther per revolution thus reducing the gearing. For example if your stock tires were 32 inches in diameter with 3.42 gears in 3rd gear without lock-up at 65 mph your RPM's would be roughly 2334. With everything else the same just changing the tire diameter to 35 inches your RPM's at 65 mph would be 2134. This is almost a 9% difference in RPM's. To get back to the stock RPM with the 35 inch tires 3.73 gears would need to be installed.

Check out this site. It has a matrix of tire size vs gear ratio. http://www.4lo.com/calc/geartable.htm

thats the website I was looking for. I have a crew cab with the 4.8 and 3.23s out back and I have recently started to haul/tow more crap in the bed. I have this dilemma as well.

beav626 · June 23, 2009

More than the weight of the wheels, the diameter of the tires will affect the gearing more. You can have your 22 inch wheels and if the tire diameter is the same as stock you will notice little difference in performance. If however your tire diameter is larger, now the tire has to travel farther per revolution thus reducing the gearing. For example if your stock tires were 32 inches in diameter with 3.42 gears in 3rd gear without lock-up at 65 mph your RPM's would be roughly 2334. With everything else the same just changing the tire diameter to 35 inches your RPM's at 65 mph would be 2134. This is almost a 9% difference in RPM's. To get back to the stock RPM with the 35 inch tires 3.73 gears would need to be installed.

Check out this site. It has a matrix of tire size vs gear ratio. http://www.4lo.com/calc/geartable.htm

thats the website I was looking for. I have a crew cab with the 4.8 and 3.23s out back and I have recently started to haul/tow more crap in the bed. I have this dilemma as well.

A friend of mine told me his shop will do it for $450 installed.

I think I will do it.

Now I need to find a tune.