Changing the gears in my suburban

[LanceRKeys]

I have decided to change the gears in my suburban (2008 5.3L 4sp auto), but not sure how much of a change to make. I currently have 3.73 gears, and was thinking 4.30 because 4.10 doesn't change much, and 4.56 may be a little too much. I have read many accounts where people thought it was great, some where people wish they had gone more, but never of someone wishing they had not changed anything. Has anyone here changed their gears and regretted the decision? If so why? Anyone think 4.30 is the wrong choice?

Last but not least, just to be clear, I am NOT trying to save on gas by changing gears. I do not plan on ever getting my money back, just trying to give my suburban a little boost in towing power.

[time2roll]

LOT of naysayers when I was contemplating 3.55 to 4.10 ratio. Most said to save the money and buy a bigger truck. All has been good for 12 years running the 4.10s.

There have been a few times 4.30 or 4.56 would have been better but not many really.

To help know what you need you will need to give more information. What speed to you cruise and what RPM? I assume it downshifts a lot over minor rise in the road? What RPM is cruising speed in the next lower gear?

Gears do not improve horsepower so much as they help keep the engine closer to the preferred RPM to make the power they can.

Yes if you are changing gears go at least 4.30 ratio. Is that even available on a Chevy?

[LanceRKeys]

I figure I will get a larger tow vehicle eventually, but for now I will continue to use the suburban. It is two wheel drive and I will change the gears myself, so it will not be as expensive as some mention. Keep the opinions comming, if nothing else, it makes for interesting conversation.

For those that suggest a new truck, post some craigslist adds, looking for something under $10,000 that can hold my family of four and tow better than my suburban, pickup preferred.

[newman_fulltime]

heck put the 4.56 and when empty taking off rev that puppy up

[ShinerBock]

jbeliera wrote:

ShinerBock wrote:
Here is a good rpm calculator if you want to know what rpms you will be at in each gear at certain speeds. May help you make a decision.

RPM Calculator

WhaT are you towing and is there a vision on the horizon of a bigger toy

I use that site for my off road toys.

[jbeliera]

ShinerBock wrote:
Here is a good rpm calculator if you want to know what rpms you will be at in each gear at certain speeds. May help you make a decision.

RPM Calculator

WhaT are you towing and is there a vision on the horizon of a bigger toy

[PDX_Zs]

I can’t resist the suburban threads.

Here’s a quick thought. It’s gonna cost you a couple thou to change your gears. I have no idea what it cost to change gears on an IFS truck, but I imagine more than a solid axle rig.

I would seriously consider taking that cash and getting a newer six speed suburban. You should be able to trade your rig and a few thousand for a newer truck.

[jbeliera]

If it is HP and torque that you want why not just go with a different tow vehicle with the engine and tranny and rear end that will cover you now and anything in the future. Those combinations are out there but you got to lay out the bucks to get them.

[intheburbs]

Seems to me like a lot of investment for little payoff. I tried making mods to my half-ton Burb, and in the end I decided to upgrade to a 2500. THAT was the best choice I ever made, not re-gearing my half-ton.

My '01 Burb had the 4L60 and 4.10 gears. I always towed in third, and the engine was around 3200 RPM at 65 MPH. I towed down to Florida, and out to the Rockies over the Continental Divide. Engine didn't have enough power/torque to hold speed in O/D, plus I didn't want to overstress the transmission. Third is a 1:1 ratio, so the tranny was just passing the power through. Regearing to a 4.30 would provide negligible increase in power, but increase your RPMs.

And also, you still have that weak 9.5" semifloater rear, which, IMHO, is the weakest part of the powertrain. If you're towing something approaching 6,000-7,000 lbs, an upgrade to a 2500 would be your best bet.

Just my $.02.

[Lwiddis]

Are you having little issues (move to 4.10 appropriate) or big issues (4.30 appropriate)? Issues getting underway? Climbing?

[LanceRKeys]

Thanks ShinerBock, I didn't think to look for one, I just channeled my inner nerd and made one on excel. Would have been easier, but not as fun to use that one.

[ShinerBock]

Here is a good rpm calculator if you want to know what rpms you will be at in each gear at certain speeds. May help you make a decision.

RPM Calculator