Rear Differential

[thehoe92]

wow..
I don't know where to start
I can't even accurately judge the difference because for starters my speedo is off big time
I'll probably have to grab one of my buddy's to see how much its off before I can even start my review

the ABS light is now on and it says service brake system so I don't know if that has anything to do with the gears

and it looks like its already sucking away my gas

the only positive is about half throttle it rips
I'm excited to see what full throttle from a dead stop will be like

 

[hoe]

wow..
I don't know where to start
I can't even accurately judge the difference because for starters my speedo is off big time
I'll probably have to grab one of my buddy's to see how much its off before I can even start my review

the ABS light is now on and it says service brake system so I don't know if that has anything to do with the gears

and it looks like its already sucking away my gas

the only positive is about half throttle it rips
I'm excited to see what full throttle from a dead stop will be like

Glad you like it, but its alot of misconception here, when people think gears will make them more hp or something. But its all physics, and everything must complement each other, The engine can be more efficient at a higher rpm. Thus getting better mpg. It may get better mpg at 2400 vs 2000. So it has alot to do with the sweet spot and the powerband /tq curve of the engine. with the final gear ratio or the tires you are even spining. I have ran 4.56s in the past and loved it, but got old as I do lots of hwy driving.

Instead of gears, cam, headers, heads, the total cost of all that can be matched & beaten with a SC real easy. Heck 1G plus a few hundred and Ill find a used SC to put on this thing. It will also add about 100 hp.

Full throttle from a dead stop will be a tire roaster, you prob half to back peddle it to keep traction. The ABS and speedo is off, truck needs a re-tune for the correct gears.

 

[Max]

Have Justin work his magic and your dash won't light up like christmas any longer.

 

[slocaddy]

hey hoe, did you have 456's in a Tahoe? or were you just explaining efficiency at differnt rpm's? you said you got tired of them did you mean bad gas mileage or turning higher rpm's? i want to order tune but am trying to decide on gears before i order. thanks

 

[thehoe92]

I never thought of it as more HP because it really has nothing to do with the engine
it has to do with the driveline rotating the axle

decided to have a wee bit of fun tonight since it was cold and I let it sit for a while
3 lane road.. celica (no clue on the upgrades), the hoe, and 2006 honda accord with a cold air intake and a couple other minor adjustments

I didn't have it in tow haul and I was around 3/4 of the throttle and instantly pulled away from the celica, kept up with the honda until 2nd gear when I let off because I didn't want to risk anything but the guy in the honda said that he was shiitin himself when he saw me right next to him and still pulling




my question is how much of a difference will the tune be?
I may be used to driving in the accord with my buddy where he just hauls ass everywhere but it seems like my gear change didn't do that much of a change

also Max what does ABS have to do with my diff?
I was almost thinking it could have been from when I replaced the hub but it hasn't lit up until I got it back today and even then it will just randomly turn on when I'm driving

---------- Post added at 05:22 AM ---------- Previous post was at 05:12 AM ----------

oh and I now have the breakdown of all the costs

Inspection: Broken Positraction, Rough Pinion Bearings, Metal in Carrier and Axle Bearings, Metal throughout housing

Performance Ring & Pinion 4.56 - $260
Rebuild Kit - $162
Axle Bearing & Seal Kit, 2 Bearings & Seals - $121
GM 8.5 2.7 & Up 30 Spline Eaton Positraction - $595
75W90 Valvoline Gear Oil (2.5 Quarts) - $22.50
Limited Slip Positraction Additive - $14
Brake Cleaner - $3.25
Labor - $340
Storage Fees - $100

Grand Total
$1725.80

 

[MUDHOE]

yea gears dont give you more hp it just gets more of what you have to the ground what kind of mpgs are you getting now?

 

[Max]

Storage fees? What a bunch of assholes The abs light is on because you're effectively outside of stock parameters on the abs tone ring in the rear differential, the pcm needs to be corrected with the proper value or it will throw a code because it thinks it is spinning at xxrpm when it is really going at yyrpm due to the gear ratio variance. No big deal you won't damage anything you just need a retune to adjust the parameters and the light will cease to illuminate.

 

[hoe]

hey hoe, did you have 456's in a Tahoe? or were you just explaining efficiency at differnt rpm's? you said you got tired of them did you mean bad gas mileage or turning higher rpm's? i want to order tune but am trying to decide on gears before i order. thanks

Ive had 4.56 in a tahoe before with 33s. The higher turning rpms is what turned me off. Power just seemed to be shifted throughout the powerband, no increase in overall power. More gas and higher rpms go hand in hand. Cam & stall has a big role to play in this as well.

2grand and im finding a used TVS1900. That price is just insane. When I had my gear done I payed 360 with all the bs addons. And still owed them like 50 bucks when I left the door. Still do too.

---------- Post added at 01:18 PM ---------- Previous post was at 01:04 PM ----------

To put things in perspective my tires are 30.45 in diameter on a 20" rim, gears are 3.73s. I can do 35mph @ 1Krpm! 105mph @ 3Krpms 190mph @ 5.5Krpms. Now think about it this way, with 4.56s I would shift my curve and have to spin ALOT more rpms to go the same speed. So you loose your top end basically, for gaining bottom end acceleration in the midrange area.

Someone with 4.56s gears will have a hard timing accelerating past 125-130. Where the 3.73s would still increase mph speeds.

To the original poster, Im not talkin about you, you need the gears to get moving again. but for the other people, money should be spent making horsepower, than swaping gears just for the sake of swaping gears. Unless you have 33s or huge tires, dont even think about it. A SC and 3.23s gears will be fun to drive, and great on mpg for instance. And have insane mph speed when on the hwy. It will also be way more tire roaster than a 5.3 with 5.11 gears.

 

[MUDHOE]

So hoe do we have an update on mpg and all the other stuff?

 

[candyman74]

gears

so you did just the rear end and not the front?

 

[thehoe92]

didn't do the front end so I don't have 4wd any more
they have broken in and what a difference!!
my speedo is still off but I've gotten used to it
it gets off the line so much quicker now
I put 22 gallons in last week and even with me at WOT a lot of the tank I still managed 340 miles which is about 15 mpg!!!
definitely an increase
highway going 65 is about 2300 RPM's and it will still get on it even in top end in fact it probably likes top end better

it downshifts every time I step on the throttle and won't shift until I get to around 90 mph

I've also noticed that when I shift at around 30 mph it doesn't lug anymore to get back up to my power band it shifts then starts pulling right away

it also rained last week and I whipped it sideways a couple times with no issues

even in puddles I'll stomp on it and feel the tires skipping then the posi locks in and it breaks loose


I love my new diff!!

 

[gmcjohn]

Just food for thought regarding burnouts and the like. I read this info on here about a year ago, and I'm glad I did! If you are burning out and you have your wheels turned be sure not to crank it because you can blow your power steering pump! Just FYI as you seem to be interested in spinning your wheels, but then again who isn't?

 

[slocaddy]

ive been thinking twice about 456's and just did some other things instead, but hearing your out come has me reconsidering

 

[candyman74]

didn't do the front end so I don't have 4wd any more
they have broken in and what a difference!!
my speedo is still off but I've gotten used to it
it gets off the line so much quicker now
I put 22 gallons in last week and even with me at WOT a lot of the tank I still managed 340 miles which is about 15 mpg!!!
definitely an increase
highway going 65 is about 2300 RPM's and it will still get on it even in top end in fact it probably likes top end better

it downshifts every time I step on the throttle and won't shift until I get to around 90 mph

I've also noticed that when I shift at around 30 mph it doesn't lug anymore to get back up to my power band it shifts then starts pulling right away

it also rained last week and I whipped it sideways a couple times with no issues

even in puddles I'll stomp on it and feel the tires skipping then the posi locks in and it breaks loose


I love my new diff!!

so did you take the front driveshaft out or what and i thought that screwed things up? also post some vids of it.

 

[Travieso]

Yes 1+ on videos.

 

[thehoe92]

Just food for thought regarding burnouts and the like. I read this info on here about a year ago, and I'm glad I did! If you are burning out and you have your wheels turned be sure not to crank it because you can blow your power steering pump! Just FYI as you seem to be interested in spinning your wheels, but then again who isn't?

the wheel is always straight when I'm attempting to do a burnout
I have never really been able to do one so I don't try anymore but if it is wet and I feel like spinning the tires the wheel is always straight

but thanks for the info

ive been thinking twice about 456's and just did some other things instead, but hearing your out come has me reconsidering

I think you should definitely reconsider especially if you have 24's or better
it would be pretty hard to drive my tahoe with 3.73's again just because of how much of a difference these gears made

as soon as I got the to the diff shop I asked if I had to do the front and they said no.. just as long as I don't put it in 4wd I'm fine.
I'm thinking about making my hoe a 2wd anyways

what would you guys like to see some videos of?

 

[candyman74]

about the gas mileage. until you get the speedo fixed your gonna think your getting better gas millage . i had a mustang and put 4.11s in the rear end and i thought the same thing i was like damn im getting better gas mileage but the speedometer is going faster than your truck is going. use a gps to to show you how fast your really going. so really your putting extra milage on your truck cause the speed is off. but anyways if you get a chance ask the rearend shop how much to do the front diff aslo.

 

[thehoe92]

I did some math and the speedo is off around 14.2 mph so when the speedo says 60 I am really going close to 45mph

this was with city and freeway driving that I got 15mpg

 

[thehoe92]

the differential has once again failed me

driving down to the bay on Wednesday and nothing went wrong.
drove to Matt14's house in San Leandro and hit a big dip in the freeway, then once I got off the freeway my left half shaft started making noise

then the next morning driving through chinatown my tires started squeaking really randomly.. it wasn't a slick surface by any means but they were squeaking

then down by the wharf I heard the dreaded clunking and grinding noise that I became so accustom to, so I pulled over and let it sit.. got on to the freeway and it wasn't making any noise

got over the golden gate bridge and the last bump made my whole rear end feel like it had just fallen out on the golden gate bridge..

pulled off into vista point on the marin county side to let it sit and think about if anything seriously bad was wrong

got out to let the air out of my bags and checked underneath and there was oil everywhere on the ground

a bolt had come loose and hit the cover and I'm guessing a ring gear got dislodged and hit the cover as well because there are perfect teeth marks of it

got it towed home with my uncles triple a 100 mile trip

now its just sitting in my driveway until I'm actually healthy enough to deal with it

it should be under warranty but I have a feeling they are going to try and ********* me and say that its not there fault

 

[slocaddy]

when things like this happen it really kills the ''mood to mod bug'' for me, i had my electric fans catch fire (junk fans) and wonderd wy even bother? sorry this happend to you.