rear axle ratio RPO

[bww3588]

Quote: Originally Posted by Gspot

i have an 87 s10 2.8L 5 spd 4x4 with a 3.73 posi, i've broken some of the disks in the posi and theres gettin to be a good build up of shrapnel on the magnet, so im lookin for another rear end, does anyone know if theres any problem with putting in a 83 blazer rear end?

as long as its 4x4 and your 87 dosent have ABS. i think in 87 they started puttin ABS on em. so the 83 wont work if yous has ABS

[Gspot]

i realized that the 83 was a 3.42 ratio, so thats outa the question, but i found an 89' 4.3L blazer 4x4 and the guy says its a 3.73 govnerlock, and he only wants $100 for it. I dont know if its got abs but i'll ask him. if it does, is there any way to make it work in my non abs truck?

[bww3588]

Quote: Originally Posted by Gspot

i realized that the 83 was a 3.42 ratio, so thats outa the question, but i found an 89' 4.3L blazer 4x4 and the guy says its a 3.73 govnerlock, and he only wants $100 for it. I dont know if its got abs but i'll ask him. if it does, is there any way to make it work in my non abs truck?

if yours dont have ABS which it should because its an 87 but any rearend will work if it dosent have ABS then your good but if the rear has it just leave it unhooked and take the sensors off from behind the axles before the tube.

[bluestreak2.5]

My 85 has descriptions next to the codes on the sticker, and they're telling me it has front and rear locking diffs with 4.11s.

[1slammedx]

the g80 is an EATON locking diff. It locks when a 100rpm difference is detected between the two side gears-the two spider gears that are splinned to the axle. it also will not or should not lock over 20 mph. it is an interesting little setup in the case. my 02 s-10 standered cab xtreme with a v-6 and a 5spd has the g80 and the 3.08 gears. it is a 8.5 ring and pinion. the same case that is in the fullsize silverados with the 8.5 .the easyest way to tell between the 7.65 and the 8.5 is the diff cover and gasket. the 7.625 is more oval shaped and the 8.5 is circular.

[s10-den]

Quote: Originally Posted by RedSpeck_09

i just checked my beater and its says GT5. that just doesn't make sense to me. a 4 banger with a 4:10 ratio? its a 95 2.2 5 speed. can anybody tell me about this?

the 4 bangers need the gears to get them moving

[s10-den]

Quote: Originally Posted by DimeTime

I have a 01 w/ 4.10, and i was wondering how much of a difference it makes in acceleration, and in gas milage, if someone has changed from 4.10 to 4.56

you dont want to do that....you will not tell the difference but you will in gas mileage.by the way,I live here in T-town too.

[low97s10]

is there any way to tell what gears you have without the rpo codes and with out pulling the rear cover. my rear end went out a couple years ago and i got one from a junkyard. he said it was the same as mine but it had the third shock and it is a diff ratio. mine had 3.73's and this is lower (3.42 maybe?) speedo reads 50 and im actually around 55

[squaredime]

any reason I have GQ1 AND GU6 on my tag in the glove box? could they not make up their mind between 3.42 and 3.73?..ool

[15sorbigger]

ok got a 89 s10 2.5L "ID", the codes i got are gq1 gt4, whats the deal.

also i want to put 22 150 spoke knock offs. is it possible or a dream.

[mikewiebe1987]

mines has three codes, gu6 g51 then g80 am i missing somthing retarded simple

[Bob35josh]

i have an 88 x cab 2.8 auto. it has 3.08's according to the codes on here. i also now have an 85 x cab with 2.8 auto. it has no sticker in the glove box and i havent got to drive it yet....still waiting on motor to be dropped. does anyone have any clue what it might be? its like i said 1985 2.8L x cab auto, s-10 tahoe, loaded out, power windows/locks, tilt wheel.
help me, please. anyone....

[2003blackchevys10]

what would it help if i changed my 2003 2.2L 5 spd from 3. 73 to 4.10 ???

[bww3588]

Quote: Originally Posted by 2003blackchevys10

what would it help if i changed my 2003 2.2L 5 spd from 3. 73 to 4.10 ???

nothing, it would make your MPG drop and 1st gear useless.

[Deezer]

I have a 2002 xtreme truck.Sorry can't seem to delete thread reposting under new thead.

[sandfly]

one way to tell what you have in gear ratio is to jack up the rear and mark the drive shaft and tire...now turn the tire one revolution and count the time the mark on the drive shaft goes aroun..it should give you a good estimate if you do it right..(3 time =308) (3.5=3:42)(3 and 3/4 apprx. =3:73) etc..

[babyboyfuz8]

should i stay with my 3.08 gears or switch to 3.42? in my 99' 4.3 gas mileage don't bother me, i want a little more torque, would that be 3.42?

[lowereds10extcab]

you said that the lower the ratio the better gas mileage... i have a '93 s10 ext cab, with a 2.8l v6 5spd and it has 3:08
gears and revs at like 5000rpm and drives at like 55 max... horrible gas mileage, i went on ALL Data and Mitchells and it told me that truck should have either 3:73 or 4:11 gears, im not sure of the numbers in the glove box but since you said that the 4cyls should have the 4:10's then does that mean i should have the 3:73's?? if anyone can help please email me jon_brown06@yahoo.com

[runuover]

i have a 95 blazer that says gu6 g80
i remember spinning one tire when ever i took a rite and both on a hard left
sometimes i could lock both on power brakin so does that mean i have a limited slip
id really like to know b/c that blazer was totalled and now i have an s10 w/ just gu6

[lstude]

I put a 2002 Sonoma rear in my 52 Studebaker. I bought it from the S-10 Warehouse but I couldn't remember what the ratio was. This thread sure helps.

Does anyone know if you can get gears lower than 4.56 for the 7.5 or 7.65 rearend? I am looking for 4.88 or 5.13

[flickjo94]

Quote: Originally Posted by speedydtp247

i'm lost. exctaly what row/column do i look at to find out what gear ratio i have?

the codes are listed in the glovebox in alphabetical order

[Head]

G75 mean anything?

[krazybronco]

ok i swaped out the original diff because the housing was broken from a wreck
so does the axle have an axle tag like ford do
if not how do i find out what it has now

just wondering

[Dranko]

does anybody know the top speeds on these different rearends with the vortec 4300 and auto tranny

[Woolford]

so the G80 is the locking diff, does that mean i have a POSI or i dont?? And i have the 3.08 gears. Im not to familiar with this stuff so are the 3.08 gears good lol??

[89-S-Dime]

Quote: Originally Posted by DoubleDown

GU4=3.08
GU5=3.23
GU6=3.42
GT4=3.73
GT5=4.10
HC4=4.56

G80 - locking differential


compare to the codes in your glove box to know which gear ratio you have

Just wanted to add that H04 = 4:11 is found in pre-1994 S10's (most commonly 4x4 Jimmys and Blazers)

[Jr's z]

does anyone have a 4.3 5 spd w/ 3.42's or 3.73's.. hows the gas milage, and the revs at 100kms/60mph?

[Woolford]

ya i have the 3.73's. Gas is a lil better than autos at like 20mpg but still shitty. And if i can remember i think my rpms are around 2500 at 60

[sippiwhiteboy]

I have a '87 2.8 extra cab 2wd. The code says it has 3.73's. Is this why 1st gear is more or less a granny gear? My heap is turnin 4500 rpm at 65-70 mph. Should I change the dif or tranny?

[hbii]

my truck has 2 codes listed it has GU6 and GQ1 so what would my Ratio be

[Blublazin]

My blaze has 3.73 behind a 6sp. With 315 x 35 x 17 tires. Turning about 1800 RPM's @ 75 MPH.

[trinityaqk]

I have a 2002 4.3 5 speed. I want to give my truck some more power/torque. I think my truck has the 3.73 rear end and I was wondering what would happen if i swapped that out for the 4.10 rear end? Is it correct that the 4.10 rear end comes in the 4 cyl s-10?

-Eric.
Trinityaqk@gmail.com

[blue blazer ed]

I have a 83 Blazer with a 2.8 . Im looking to chrome out the rear end.

Going to junk yard to get one so my Blazer wont be down while this is happining. My question witch rear end should I look for , what year to what year to look for, and will the U joints be the same?

[sonofavette1]

ok my code for my x blazer is GU6 and G75 so what the hell is G75

[ka_jd7and1]

Quote: Originally Posted by sonofavette1

ok my code for my x blazer is GU6 and G75 so what the hell is G75

G75 : AXLE REAR, 3.62 RATIO

Heh, I think you got a typo somewhere.

[BLAZIN1990]

will 3rd gen blazer rearends bolt right up to a 1st gen blazer

[berrong]

Quote: Originally Posted by DoubleDown

GU4=3.08
GU5=3.23
GU6=3.42
GT4=3.73
GT5=4.10
HC4=4.56

G80 - locking differential


compare to the codes in your glove box to know which gear ratio you have

what if there is not a sticker in the glove box how else can i find out

[Rinkrat456]

Quote: Originally Posted by berrong

what if there is not a sticker in the glove box how else can i find out

Put wheel chocks up front, lift the rear on jack stands. Take the differential cover off and rotate the wheels until you see two numbers marked into the ring gear. Divide the large number by the smaller number (for example, 41 ring gear teeth divided by 10 pinion teeth gives you a 4.10 ratio). This is the sure fire way of knowing what ratio you have. There are others, like turning the wheel and watching how many times the driveshaft goes 'round, but that's eyeball and usually wont get accurate enough to tell the difference between 3.42 and 3.73, and 3.73 and 4.10, since the ratios are close together.

Chances are you needed a fluid change and new gasket anyways. $40 well spent.

Forgot to add the pic.
Here's the numbers I'm referring to. ALL American axles have these numbers stamped into the ring gear. The blue circle is what I'm talking about.

[ps2141]

I have a 85 s-10 standard cab extended bed. It has the 2.8 v6 with a 4 speed manual and 2 wheel drive. I dont have a sticker in my glovebox so i was wondering if anyone had an idea of what gears it would have thanks

[Rinkrat456]

Quote: Originally Posted by ps2141

I have a 85 s-10 standard cab extended bed. It has the 2.8 v6 with a 4 speed manual and 2 wheel drive. I dont have a sticker in my glovebox so i was wondering if anyone had an idea of what gears it would have thanks

Read the post above yours.

[RMcCourt]

I am confused.

First, I have a 96 SS with 97K GU6 (3.42) G80, and an 01 with 19K GU6 G80.

I was under the impression that the lower the number, the better the acceleration. For example, with the 3.42, for every 3.42 revolutions of the transmission output, you rotate the gear driving your tires 1 time. Likewise if you had a 4.10 you would need 4.10 revolutions from the trans to get the same 1 revolution on that final wheel gear. If that is correct, then the fewer revolutions you need the quicker you can go.

However, after reading this thread, everyone seems to be sayiing the opposite... that a 4.10 will provide better acceleration. If this is accurate, then please help me to understand why this is the case.

Thank you,

~Ryan

btw - this is my first post here.

[kandel123]

ok The G80 is a locker. General motors calls it there "G80 Locker" it locks when the weights in the diff sense i difference of 100 RPM. It locks 100% but if you let off the gas it will dissengage. If you power brake the rear end it will not unlock untill you get out of the throttle. When you release the pedal it becomes an open rear end untill it senses a 100 rpm difference

[Eddygordo23]

Quote: Originally Posted by Nate8727

Ok here is a rundown of the different cabs and engine combos for differentials. I found this out just by building an s-10 on chevy.com

2.2 4cyl- regular cab LS - manual tranny/3.73
auto tranny/4.10

extended cab LS- manual tranny/4.10
auto tranny/4.10

regular cab xtreme- manual tranny/3.73
auto tranny/4.10

extended cab xtreme- manual tranny/4.10
auto tranny/4.10


4.3 6cyl- regular cab LS- manual tranny/3.08
auto tranny/3.42

extended cab LS- manual tranny/3.08
auto tranny/3.42

regular cab xtreme- manual tranny/3.08
auto tranny/3.42

extended cab xtreme- manual tranny/3.08
auto tranny/3.42

Positraction is not available on the 4cyl engines

Positraction is available on either the 6cyl manual or automatic transmissions. I didnt get it in mine, darn it I should of ordered one. Ah crap... oh well, better luck some other time. arrrrrr

ANYWAY ENJOY, IM SURE ALMOST EVERYONE IN HERE WILL

now this says my truck being a 2.2 5spd is a 3:73 but the first post in this thread says the code GT5 is the 4:10 and that is the code i have. so which do i got?

[Eddygordo23]

nevermind i got it figured out

[Madkaw_16]

To clarify for some people wanting to change a 3.73 to a 4.10. I changed mine in my '00 4dr. with a 4.3 auto, and it has really good acceleration, but my mpg went from 23, to 18. I'm gonna have some fun with it for a while, but will be changing it back shortly.

[TitusvilleSurfer]

I was rear ended and my axle was bent. Instead of replacing the axle I swapped the whole rear end from 3.73 to 4:10. I knew a guy with a V6 who had an extra so it was a cheaper job. I enjoy the faster pickup from a stop sign, my 3.73's were just too slow. I did suffer on gas millage but think it was worth it. 2001 2.2 LS 5-speed

[ss350]

Just wanted to update this sticky.

On 98-01 Blazers 7 5/8 ring gear, 28 SPLINE, the length of the axle is 26 3/8".

On 98-01 S10/S15 Trucks 7 5/8 ring gear , 28 spline, the length of the axle is 26 5/8". I had to learn this the hard way.

Quote: Originally Posted by Larry Black

there are two different types of axles used. the number of splines that fit into the spyder gears make the difference. all other spec's are the same. to find a posi, limited, locker, try light line of Louisiana. they have fairly diecent prices. www.lightlineofla.com.

[lowxpectationz20]

anyone got some 308s they want to sell?

[jd101proof]

simple solution.....if you want to know what gears are in your truck without crawling around, or extensive research on the net.....the next time you are cruisin through town, stop at your chevy dealer parts counter with your VIN# and have the parts guy look it up. of course this wouldnt work if someone else swapped your rear, but chances are that they havent since it is a commonly overlooked item. hope this helps! -also, you can find out darn near anything from the parts dept by your VIN#

jd