Gear Characteristics

Silver-Dollar · August 16, 2004

What is the purpose of changing to 4.10s? Is is to get to the meat of the power curve quicker? How much time is saved? And is it worth the 500/600 rpm difference for mph lost with the change? Since you rev quicker, doesn't that mean more shifts/different shift points/higher rev limits?

042500HD · August 16, 2004

Mine has 4.10's in it and its not all that bad in my opinion i would always go with the lower gears over the 3.42's but thats just my opinion.

Silver-Dollar · August 17, 2004

Based on an on-line calculator, here are the numbers for 2000 rpms with both 3.42 and 4.10s on 30" tires with the 4l60e.

3.42

1st 2nd 3rd 4th

17 32 52 75

4.10

1st 2nd 3rd 4th

14 27 44 62

Difference

1st 2nd 3rd 4th

-3 -5 -8 -13

Granted the numbers aren't bad for 1st and 2nd, but a 13 mph lost at highway rpms. To get to the same mph with 4.10s you will need 2400 rpm. I guess that is not to bad. However, on the othe side lets look at 5000 rpms

3.42

1st 2nd 3rd 4th

43 80 130 186

4.10

1st 2nd 3rd 4th

36 67 109 155

Difference

1st 2nd 3rd 4th

-7 -13 -21 -31

I know that I never run over 100 mph on the roads but need to out the data down fo comparison. But as you can see the mph differences involved. Which brings up the time question again. How much time is cut by say reaching 80 mph? With the 3.42s, I will still be in 2nd with a few hundred rpm to spare. With the 4.10s, I will be at 6000 rpm in second! Actually would have shifted and running at close to 3700 rpms.

I think I answered one of my questions about the power curve. At WOT, upshifts will be in the higher rpm range. Thus, more power availability. With that being said, what would be a good stall speed be for 4.10 gears without being to radical?

awdvkd · August 17, 2004

The only reasons the change from a 3.42 to 4.10 is if you tow and want to tow more or you are going to a much larger tire. You don't say much as to why you considering the trade out so thats a nut shell explanation

stebob · August 17, 2004

The 4.10's will yield quicker acceleration at the expense of top speed. Also, running 1700 RPM's on the highway is not really where you want to be running a V-8 anyway. V-8's will run better around the 2200 mark, that is where their power is, not down that low.

mazingo · August 18, 2004

I have been wanting 4.10's for a while and I use TCI's calculator to figure my ratio and rpm differences when swapping from 3.42 to 4.10. It isnt real bad at 65 you will only be turning around 2100 +/- given the size of your tires.

I love the way my truck pulls in 2nd and 3rd gear. Sometime I ride through town in 2nd just to hear the exhaust . The 4.8L really turns up after about 2500 rpm. Sometime I sware you can almost feel more fuel or something once you get to about 3500 or so.

I think gm should have made all these trucks stock with no less than 3.73's

Has anybody had the 4.10's installed and if so what was the total price? I want to be able to get a good deal and would like some prices before I go to a shop.

Silver-Dollar · August 18, 2004

I was wanting 4.10s strictly for acceleration purposes. I do not do any towing or plan to. From what I have read, 4.10 are as high as you may want to go to keep the vehicle as a daily driver. Keep in mind, I say that with tire hieght considered.

As far as price, the gears and install pack sell together at Jegs for about $320 + shipping. As far as install goes, I have received two quotes. Both were identical in labor rate ($75/hr) but were different on install time when asked. One company has been around along time and the other fairly new. The fairly new one said 4 hours to do the install and the other said up to 8 hours with the possibility of having to do multiple setups to achieve proper depths and backlash.

With that being said, it is a toss up who I take it to. I like the idea of dropping it off in the morning, go to work, and come back a little after lunch to pick it up. This way it definetly keeps the wife out of the loop.

Still wondering about a good stall range for these gears.

hercman · August 20, 2004

It sounds like the 8 hour job is a high estimate. The other one seams like they tryin to lure you win with a short estimate. If I was you I'd go with the one that's been around longer. Even though they estimated longer on the job time if they come out sooner you won't be out any more then you planned on where with the quick time It'll probably run over and cost more then you anticipated. As for the gearing I don't have a comment I like my MPG with the 3.42.

zippy · August 25, 2004

we went from 3.42 to 4.10 in a buddies rcsb 2wd with a 4.8 and 4L60E. it made the truck a much better driving truck around town and not bad at all on the highway. deffinitly helped out towing. the tire size was 275/45R20 which is about the same as the stock 255/70R16's (this had a 3/4 drop). his fuel milage was around 19 on the highway after and about 20-21 before. didn't get to find out, but was probably worth about .3 in the quarter.

Silver-Dollar · August 27, 2004

Thanks for the info. Talked to another installer who was recommended by the parts store. He builds race cars and said he would do the install for $350. Kaching.

However thats were the bargin ends. He suggest using US GEAR/STRANGE for the ring and pinion. I have seen them on-line selling for about $190. That is a fair bit more than the Richmonds I was looking at.

He also suggest replacing the Eaton G80 with an Auburn Pro series LSD. This will add some serious damage to the budget. Any thoughts on this suggestion?