4.10's?

JeepinJarhead03 · **Posted:** Fri Apr 24, 2009 3:51 pm

Tell me somethin

What happens when you take two sets of identical 4.10's and turn one at an ever so slightly faster rotation than the other due to a transfer case?

tommudd · **Posted:** Fri Apr 24, 2009 3:57 pm

how slightly faster
and
due to the transfer case?

JeepinJarhead03 · **Posted:** Fri Apr 24, 2009 4:04 pm

fast enough that they tell you not to operate it on even moderate traction surfaces

Don't the CT's turn the front slightly faster than the rear?

and by the way this isn't an argument on needing to match the front and rears to such degree

it's more of an statement that in some cases it doesn't matter if you do or not when you pull the stick it becomes unmatched - that is if it's true that the CT's do turn the front faster than the rear to some degree

CRD Joe · **Posted:** Fri Apr 24, 2009 4:44 pm

I didn't mean to cause a fuss. I just figure that if you're buying two sets of Yukon 4.11's that's what you're getting. I'll go back to sleep now.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

As far as my 4.10's are concerned, they are Yukon C8.25-411 in the rear, and the front diff from a 4 cylinder up front. The box for the Yukon ring and pinion says 4.10 rotational. The 4.10's in the front diff are actually 4.09's. Been like this for many years with absolutely no problems even if running in FT4WD on the highway. It's always been explained to me that this is how it should actually be.

CRD Joe · **Posted:** Fri Apr 24, 2009 4:53 pm

Thanks for clarifying.

tjkj2002 · **Posted:** Fri Apr 24, 2009 8:24 pm

All 4.10's for the 8.25 are actually a 4.10:1 ratio,the front axle uses 4.09:1 gear ratio but is called 4.10's.There is no such thing as 4.11's for the 8.25.My Yukon 8.25 gears are 4.10's.Anymore then 0.01:1 difference is very bad.

JeepinJarhead03 · **Posted:** Fri Apr 24, 2009 8:39 pm

thanks for that info tjkj i had the misconception that the CT caused the difference in ratio

ATXKJ · **Posted:** Sat Apr 25, 2009 12:34 am

a V6 has a torque peak at 4000 rpm
a CRD has a torque peak at 1800 rpm

if you're gearing them the same - one of them's wrong.

tommudd · **Posted:** Sat Apr 25, 2009 7:59 am

but you are talking about torque PEAK, do you run at torque peak all the time in each? Don't think so :roll:

tjkj2002 · **Posted:** Sat Apr 25, 2009 8:19 am

ATXKJ wrote:

a V6 has a torque peak at 4000 rpm
a CRD has a torque peak at 1800 rpm

if you're gearing them the same - one of them's wrong.

Wonder why my Father opted for the 4.30 gears in his SD over the normal 3.73's(OEM option for SD's),get's better mpg's and tow's more then the 3.73 equipted SD's.

CRD Joe · **Posted:** Sat Apr 25, 2009 9:28 am

It seems to me you'd want to gear a daily driver for optimum peak torque at highway speeds. Wouldnt you gear your rig for peak torque in its final drive? You have lower gears for all the other speeds...... I like to drive 60mph. I like the mileage I get at that speed (62+ in my TDI) I like the fact that with 4.10's and 31.5" tires the math indicates a CRD would be at 1758rpm at 60mph. Peak torque and great mileage....

ATXKJ · **Posted:** Sat Apr 25, 2009 6:35 pm

60 would get you run over in Texas

speed limit on the drive across town is 70, I35 is 75 and I10 down South is 80

if you're going 60 you'd get run off the road.

and I don't Tow

ATXKJ · **Posted:** Sat Apr 25, 2009 6:38 pm

tommudd wrote:

but you are talking about torque PEAK, do you run at torque peak all the time in each? Don't think so :roll:

That's also the BSFC minimum - so Yes for optimum mileage and performance - I want to be at the Torque peak.

CRD Joe · **Posted:** Sat Apr 25, 2009 6:40 pm

ATXKJ wrote:

60 would get you run over in Texas

speed limit on the drive across town is 70, I35 is 75 and I10 down South is 80

if you're going 60 you'd get run off the road.

and I don't Tow

Who said you tow? Im not in Texas, while sometimes I wish I was. People around here are commie loving turbo greenie idiots! That said they dont run you off the road. You didnt address the issue I tried to make a point about. Wanting peak torque at the speed in the final drive you use most often seems to me most logical. Do you disagree?

ATXKJ · **Posted:** Sat Apr 25, 2009 6:48 pm

The Tow comment was for TJ - I don't doubt a Powerstroke used for towing would work better with lower gears

I do agree that you should be targeting the torque at the speed you use most often - for me that's 70+
(which is why I think the 4.10 for everything is a bad idea for diesels)

around here most folks try to be friendly -
but our greenie idiots have elected no-growth politicians that fight against building new roads even when the moneys there -
the result is overcrowded roads and when you're slow enough that the 18 wheelers are trying to pass you - it's a problem.

CRD Joe · **Posted:** Sun Apr 26, 2009 10:47 am

Roger that AT. That really isn't a problem here in Warshington. He'll it takes you guys days just to cross your bloody state! I recently drove down to Arizona to visit my mom. I drove 60mph the whole way and I got 62mph with my TDI Jetta. Nobody cared that I was driving 60!

ATXKJ · **Posted:** Sun Apr 26, 2009 5:44 pm

As a side note on highways.

I35 got a lot worse with NAFTA - you have a lot of 18 wheelers running to & from Mexico - they're always in a hurry
the section where they're banned from the left lane - they weave in and out of the right lanes
the section from San Antonio to Dallas is pretty much bumper to bumper 24/7
They're building a lot of Toll roads to take the extra traffic but it'll be years before they're finished.

on the other hand I10 down south the limit is 80 - and despite the mpg penalty - I highly recommend you try to be close to that
it's not crowded - but it's 500 miles from San Antonio to El Paso and the scenery is interesting for 10-15 minutes

JeepinJarhead03 · **Posted:** Sun Apr 26, 2009 6:04 pm

we got a 100mile stretch of highway out here that goes from around greenville to raleigh

theres nothing within 15 miles of the highway off any exit for like 90 miles and the SL is like 70, but the only time they'll pull you for going over 80-90 is if it's raining

unless ya think trees and ponds are scenery, theres nothing to look at other than the road, which is a very bland grey :lol:

CRD Joe · **Posted:** Mon Apr 27, 2009 11:31 am

Ya I understand. I'm the odd du k who's never in a hurry going anywhere. That said, I pay attention to my mirrors and I'm never a neusense to other drivers.

4.10's?

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