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.

[colliehauler]

LanceRKeys wrote:
Thanks for the comments everyone, these discussions are helpful. The 2001 looks nice, but if I get another SUV it will probably be a V10 excursion. This vehicle will not be replacing our current suburban, and I have always wanted a V10. I am still looking for just the right truck, but until then, might as well see what I can do with the suburban. If I change the gears and don’t like it, I can always change them back.

A lot of people shy away from the X because it's getting a little long in the tooth. I love them for towing. I have a V-10 2wd X and a 7.3 4wd X.

[LanceRKeys]

My kids are still in car seats, a quad cad is to small, their legs don’t have any place to go.

[mowermech]

LanceRKeys wrote:
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.

That's easy; but you can't have it, I bought it!
1999 Dodge Ram 3/4 ton quad cab 4X4, Cummins diesel, 5 speed manual. It holds me, wife, and two grandsons quite nicely. I bought it for $9000, because my 2001 Dodge half ton didn't have the towing capability I wanted. At the time, there were a couple of others in town that were similar, and about the same price, but this one had a huge aftermarket front bumper and grill guard!
With 3.55 diff gears, it gets about 23 MPG when not towing.
I am VERY happy with it. Re-gearing the half ton just was not an option, IMO.

[dodge_guy]

I agree on the gear change even in a 1/2 ton. It will make towing in hilly areas much more pleasant. I wwas ips also look into a custom tune from black bear tuning. They are the go to tuning company for GM gas trucks. And when you find a V-10 Ford truck 5star is the place to go! Worth every penny to do a proper tune!

[LanceRKeys]

Thanks for the comments everyone, these discussions are helpful. The 2001 looks nice, but if I get another SUV it will probably be a V10 excursion. This vehicle will not be replacing our current suburban, and I have always wanted a V10. I am still looking for just the right truck, but until then, might as well see what I can do with the suburban. If I change the gears and don’t like it, I can always change them back.

[APT]

2001 6.0L will be no different, well little different. 4th gear ratio is taller for the HD trans.

4.30 will put you right at 3000 rpm.
4.56 you are looking at 3180 rpm.

Is that where you want to be?

This is a good fundamental point. Is that where you want to tow? The engine will be fine. Might be a little louder than your current 2600rpm. That is right in line with what I tow at, between my 4th and 5th gears, 2300-3100rpm. Sometimes my wife, ahem, comments if it's in 4th/3000-3300rpm for a while.

4.56 will still downshift on some hills. Just fewer of them, or later. It will offer a good bump in acceleration, but unlikely let you tow in OD. The 5.3L

If you really want to change and down't drive at 80mph unloaded often, then go 4.56. Don't forget a tuner to adjust the trans shift points. If you have 2WD, then it's pretty cheap, as little as $500.

Have you considered something with a 6-spd trans? Your Suburban is one year shy of GM changing to 6-spd. The 2007+ Yukon Denali has it (with the much more powerful 6.2L). The 2008+ 3/4 tons, and 2009+ half tons got 6-spds which does make a big difference to when I towed with a similar geared 4-spd.

[bucky]

I took a prior 2500 Burb to 4.10s from 3.73's. Put it right in the sweet spot for interstate towing. Could stay in OD all day at 65 mph regardless of terrain with a 8700 lb TT. (99 7.4)

[Dadoffourgirls]

intheburbs wrote:

LanceRKeys wrote:
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.

2001 Suburban 2500, 121k miles, $7800

That is a very nice looking Burb. Downside is just the 6.0 with the 3.73. Therefore, not towing the heavy bumper pulls.

The upside, in my opinion, the best power front bucket seats ever!

[colliehauler]

intheburbs wrote:

LanceRKeys wrote:
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.

2001 Suburban 2500, 121k miles, $7800

I would recommend finding a used 2500 Burb as well, drive train is better suited for towing.

I speak from experience on changing gears on a half ton to make it tow better. Ended up selling and buying a three quarter ton.

[intheburbs]

LanceRKeys wrote:
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.

2001 Suburban 2500, 121k miles, $7800

[dodge_guy]

The engine will be working less with the 4.30 gears. You will be able to tow in OD and when it does kick down it will still be the same rpm spread. The gear change will make the truck more efficient when towing.

I went from 3.73 to 4.30 in my X and it was the best thing I could’ve done. I kind of wish i went to 4.56 sometimes. At 67mph in OD I’m at 2300rpm, if it kicks into 3rd at the same speed I’m at 3k rpm.
The LS motor will have no problem if and when it has to spin at higher rpm. Hell my X routinely sees 4k rpm at 60 on the big mountains out west and in the east.

[LanceRKeys]

I was hopping to prevent the downshift altogether, although you do bring up a good point. I would have to slow way down before a downshift.

[PDX_Zs]

What size tires are you running? I have seen anything from 4.10 to 4.88 work well depending on ones tolerance for revs.

Anyway, ignore my previous. Two wheel drive, and if you can do it yourself... easy and cheap enough to try.

I also know that 2wd subs aren’t super hot on the used market. So you would need to toss much more money at the problem to get a newer rig.

Here’s an idea. Can you pull a full 14-bolt from a Silverado 2500 and drop it in? Lots of those went out with 4.10s. By then you are stuck with mismatched lugs.

Keep us posted on your progress.

[time2roll]

4.30 will put you right at 3000 rpm.
4.56 you are looking at 3180 rpm.

Downshift will put you at 5070 and 5380 rpm respectively.

Is that where you want to be?

I also needed a tuner to correct the speedo (you may not). I used this to reduce my shift points 500 rpm. I really do not need to be at redline when towing. This also helps prevent the downshift.

[LanceRKeys]

I like to tow around 65mph, which puts me about 2600rpm +/-. I pull in direct, or 3rd in my 4 speed. It can't really pull OD even on flats unless there is NO wind, which never happens in the Texas panhandle. It does downshift on minor rises in the road, which puts it in 2nd and 4400rpm or so (which it can gain speed rapidly at that RPM. From what I have seen, 4.30 is available, but I have not narrowed it down to make sure yet.