4.10 or 4.56?

[4x4junkie]

I ground my 5.13 8.8 gear. It was probably between 1/16 - 3/32" that I had to take off the very tip of two teeth. You could probably go as much as 1/8" before you'd start getting into the tooth contact area.
As for it causing a stress riser, there's no load placed on the tips of the teeth, so how could it be stressed there?

Also, there are two styles of notched pins (one is "stepped" (usually factory), the other has a center cutout (aftermarket)). Neither is as strong as a solid pin. Stress is put on the entire length of that shaft, no matter where it's notched.

 

[michowski]

I got another question. I dont wanna start a bunch of threads so il just keep it in here. Im thinking of doing a l/s in the rear and an arb air locker or auburn electric locker in the front. This is my daily driver and im just curious how this setup would work with the 4.56 gearing.

 

[rickcdewitt]

with 4.10's and 33's my truck turns about 2600 rpm's at 65 in over drive.i had 4.56's and liked the power but not the cruise rpm's.i commuted 50 miles to an awsome shop i worked at and when 4.10 axles fell in my lap for 100$ complete i ran them for commuting but i woulden't want to tow up a hill with them its like car gearing.i work closer now and the 4.56's are going back in so it can be a truck not a commuter again.its been said here that you get a little better mileage with the engine not working as hard even if its at a higher rpm.i get 17mpg now i guess time will tell.

 

[Wicked_Sludge]

your numbers dont add up. 33's with 4.10's will turn close to 2700 rpm at 65MPH with a 1:1 ratio (thats 4th gear in your 5 speed). overdrive is around .79:1, which would put your rpm at about 2100.

4.56's with 33's will turn 3000 rpm in 4th, 2370 in OD.

you get better mileage by running your motor near its peak torque rpm...your 2.9 has a relitively low peak, so higher rpm will probably decrease your mileage.

michowski, a l/s is great on the street, and will perform well off road if you dont lift tires often. the locker up front is a good idea...but it will put a lot of added stress on the front drivelines when locked. full circle clips would be a good idea, and dont be afraid to unlock it to make turns (turning and giving the truck gas while in 4wd is when front axles usually pop).

 

[rickcdewitt]

your numbers dont add up. 33's with 4.10's will turn close to 2700 rpm at 65MPH with a 1:1 ratio (thats 4th gear in your 5 speed). overdrive is around .79:1, which would put your rpm at about 2100.

4.56's with 33's will turn 3000 rpm in 4th, 2370 in OD.

sounds like you are getting your #'s from the tech library.you have to remember that tires are never actually the height they say they are.my speedo is only off by less than 1 mph(checked by several radars) and its 2600 at 55 in 4th,about 2650 at 65 in overdrive.3100 at 65 in 4th.how did you get those #'s? my brothers jeep has 4.56's and 33's also and he turns about 3000 at 55 in direct drive with the converter locked up.sorry man but actual #'s from very different trucks doesn't lie.try calibating your speedo
i was sketchy about the 4.56's because in overdrive(mitsu tranny)at 55 you turn 2600.
my isuzu has 4.55's stock and that 4 banger revs like crazy on the freeway with 31's(its completely stock and the speedo is accurate.

 

[Wicked_Sludge]

...and its 2600 at 55 in 4th...

...i was sketchy about the 4.56's because in overdrive(mitsu tranny)at 55 you turn 2600...

which is it?

you may have actual numbers from actual trucks...but they are incorrect. both vehicles will turn the same rpms, with a 1:1 ratio, the same differential gearing and the same tire size. yet you say the jeep turns 3,000 RPM at 55 and your truck only turns 2,600 rpm.

none of your numbers are adding up.

 

[rickcdewitt]

which is it?

you may have actual numbers from actual trucks...but they are incorrect. both vehicles will turn the same rpms, with a 1:1 ratio, the same differential gearing and the same tire size. yet you say the jeep turns 3,000 RPM at 55 and your truck only turns 2,600 rpm.

none of your numbers are adding up.

sorry to confuse you i could have been a little clearer.if you look in my signature you'll see i run 4.10's,when i refered to the jeep having 4.56's also i was talking about your rpm quote with 33's and 4.56's not my ranger(although i do have some 4.56 axles i took out of my truck 2 years ago)

 

[Wicked_Sludge]

ahh, ok.

but something still isnt right. perhaps your buddies speedo hasnt been corrected for the 4.56/33" combo.

i didnt take into consideration your toyo-kogo tranny's .85:1 overdive before...your setup (4.10/33") should turn close to 2700 rpm at 65 in 4th, 2295 in OD. according to the numbers you claim, your 33's are only 29" tall

 

[rickcdewitt]

yes my brothers jeep is 5 mph off but it turns the same rpms as my ranger when i had 4.56's if you correct for it.your numbers being off by 300 rpm's is really pretty close for an equation.maybe the ford equation using revolutions per mile would be closer.none of the equations i've used on different cars and trucks have come out dead nuts,the only way i've found to really know is to get out there and drive it.from what i've found 4.56's give a good cruise rpm at 55-60 in overdrive and 4.10's at 65-70 in overdrive with 33's(or should i say32-32.5)

 

[Wicked_Sludge]

my calculations are 400RPM different then the numbers youve given...thats 14% error and not acceptable. something isnt right here.

to calculate engine RPM, you have to start with rotations per mile...so its the same equation: 5280/(diameter X pi/12)=rotation per mile. then times that number by the differential gear ratio and you get RPM at 60MPH (60mph=1 mile per minute).

 

[rickcdewitt]

i get the feeling you don't drive any thing with 33's and 4.10's or 4.56's on a regular basis.all i can say is put some on your truck and see what you get,my numbers are real world forget the equations.if it was only one truck with those #'s i'de suspect the instuments but when you run multiple vehicles past different radars its pointless to argue.if you don't have experience with those set ups lets give the poor guy his thread back and put the calculator down

 

[Wicked_Sludge]

ive driven several combinations of tires and gears over the years. i am actually planning on running 4.56's with my 31's eventually. the reason im arguing my point is because 400 RPM could be the deciding factor for michowski, and i want him to have accurate information when he makes his decision. your numbers may be "real world", but they are still wrong. im sorry man, numbers dont lie.

im not saying you dont have these gears or these tires on your vehicles. im saying something got mixed up somewhere along the way. perhaps your tach is off, perhaps you werent in a 1:1 transmission gear, ect.

 

[rickcdewitt]

ive driven several combinations of tires and gears over the years. i am actually planning on running 4.56's with my 31's eventually. the reason im arguing my point is because 400 RPM could be the deciding factor for michowski, and i want him to have accurate information when he makes his decision. your numbers may be "real world", but they are still wrong. im sorry man, numbers dont lie.

im not saying you dont have these gears or these tires on your vehicles. im saying something got mixed up somewhere along the way. perhaps your tach is off, perhaps you werent in a 1:1 transmission gear, ect.

insist all you want but like i said my #'s are from more than one truck and i know what direct drive and overdrive are.also if you plan on 4.56's you better have a 4 banger like my isuzu with factory 4.55's and 31's.it revs like crazy on the freeway even in overdrive.also the ford equation uses circumfrence to start not diameter because you get a more accurate measurement.sure you can convert it but the initial measurement is where your inaccuracy comes from.i don't know where your problem lies but i know enough about scientific method to rule out one of your moron scenerio's where i put it in 3rd instead of 5th.my tach has been checked at the smog machine at work and more than one radar has checked the mph.i'm perfectly clear on my tranny ratios and it doesn't have some fancy close ratio shit.i've run more than one set of 33" tires without any noticable change so that rules out the set i'm running now.are there any other variables i'm forgetting?accurate tach,speedo,consistant tires.and on more than one truck! you should know from school that equations are made to mimic reality and as such aren't always accurate.i'll be saying i told you so when you add two stroke ports to your motor so it can run at 75 with 4.56's and 31's.anyway this is pointless, why not try starting a thread asking what rpm's people are turning with 33's and 4.10's or 4.56's.go ahead and have the last word,then let michowski have his thread back.

 

[michowski]

no go ahead and carry on. Its good info and good knowledge to know. I think my questions were answered already anyway so carry on

 

[Wicked_Sludge]

thanks michowski...but i am sorry for boogering up your thread.

rick, i dont have a 4 banger, i have a 3.0..which is why ive decided on 4.56's. it'll allow me to access my motors high peak torque, but ill still only turn around 2500 rpm in OD at 65mph.

fords IDS (the software they use at the dealership), has an integrated calculator that takes the tire width and aspect ratio and converts it to circumference. it does the exact same calculation im doing...only it uses millimeters.

THIS CHART shows rpm vs tire size/gear ratios. on my truck with 3.73's and 31's at 65 (corrected speed), i turn around 2500 RPM in 4th...if we refer to the chart, we see it shows this combo as turning 2628.

both my escorts with 24" tires and 4.11's turn 3700 RPM in 4th at 65. according to our chart, thats right on.

i had a 74' wagoneer for a while with 30" tires, 3.54 gears, that turned a little over 2600 rpm (no torque converter lock up) at 65. low and behold, it matches up to the chart as well.

theres 4 vehicles (3 of them bone stock...so speedometers are without a doubt correct) that follow the equation.

im trying to figure out why it is that you think you and your brothers trucks for some reason doesnt have to obey the laws of physics. this is simple math. i realize a tires ultimate diameter isnt always the same as whats advertised...but ive never seen a tire advertised as a 33 that was only 29" tall.

you can argue with me all you want...but again, the numbers dont lie. something in your guys' setups doesnt pan out.

EDIT: most of the time, when i see those little "your speed is:" radar units, they are near town, at a point where the speed limit is reduced from a higher speed. just out of curiosity, at what speed did you radar check your speedometer?