Rear Diff Question

hy_69 · February 11, 2011

ok.. so i have a '99 silverado ext cab 4x4 with the 5.3L.... bought it like a month and a half ago... today i had my differential opened cause it had a weird noise when shifting into D or R... turns out it is a planetary that is a little worn... the guy put everything back on the way it was and told me to use it till it breaks! which should take a while! he told me not to worry about it yet! but i want to know what to do when it breaks! can i change the inner parts of the differential?

do i need to buy a new differential? what should i get? eaton locker, truetrac LSD?? (i was watching some videos on youtube of silverados like mine with factory g80 locker and the seem to function really cool)

i dont even know what type of differential i have! can someone help me figure this out by seeing the picture? oh btw! the guy told me i have 4.56 gears ratio, i'm running 35" tires...

thanks in advance! any help would be appreciated...

i will really like to know what type of differential i have in case i can get like a rebuild kit to change the planetary and the little springs in there or what ever it needs....

chakis24 · February 11, 2011

check the glovebox. if theres an RPO code that says G80 you have the auto-locking rear. otherwise you have an open diff. the G80 is built buy eaton for the gm trucks. but if the previously swapped the gears- he couldve swapped the locker too. get in touch the previous owner if you can and ask.

if you have a 4.56 gearing then youre not running stock gears. 4.10s were and still are the lowest offered.

hy_69 · February 11, 2011

check the glovebox. if theres an RPO code that says G80 you have the auto-locking rear. otherwise you have an open diff. the G80 is built buy eaton for the gm trucks. but if the previously swapped the gears- he couldve swapped the locker too. get in touch the previous owner if you can and ask.

if you have a 4.56 gearing then youre not running stock gears. 4.10s were and still are the lowest offered.

i'm the 3rd owner of this truck... the previous owner had it like 3-4 months... he bought it to sale it and make some money so he has no info about the truck... he told me the first owner changed the gears on it and thats it! he didn't know what gears they were he just knew the first owner changed them... i know for sure it has 4.56 gears cause the mechanic told me.... when i checked my vin number in a webpage to see the specs in my truck for the differential it said i had the g80/lsd/locker or something like that... but according to the mechanic that ain't the stock differential! so thats why i'm asking if there is a way by looking at the picture to know what type of differential is it?? is it the g80 locker (stock), or something else? he mentioned something about auburn gears or something like that but i'm not sure he really knew what he was talking about...

Diesail · February 11, 2011

G80 is an option code for limited slip or locker. Whether it is a LSD or Locker depends on the year and the model of the vehicle. But the G80 code is used for both. By the looks of the unit it would appear to be a limited slip. I don't know what the G80 was in '99 but if I had to guess that is stock. If it was me and I needed to be replaced I would replace it with a truetrac if available for the axle.

hy_69 · February 12, 2011

ok.. so i went to another guy that really knows what he is talking about! told me i have a LSD differential! when it was brand new he says it is supposed to be very good! but since it has several miles on it! it doesn't work the way it should anymore! and i bought a almost new g80 locking differential! then one that some stock silverado has! he recommended me this one! so i did some research! saw several videos of how it works! and i said! for $150 i'm paying for the differential it does exactly what i want it to do! so i'm having it installed on tuesday! i hope i like how it will work....

dlstewart01 · February 12, 2011

G80 is an option code for limited slip or locker. Whether it is a LSD or Locker depends on the year and the model of the vehicle. But the G80 code is used for both. By the looks of the unit it would appear to be a limited slip. I don't know what the G80 was in '99 but if I had to guess that is stock. If it was me and I needed to be replaced I would replace it with a truetrac if available for the axle.

All G80s installed in trucks were mechanical locking diffs with the exception of the quadrasteer which could have a G86 limited slip. Cars got the G80 limited slips.

G80 locker

hy_69 · February 17, 2011

G80 is an option code for limited slip or locker. Whether it is a LSD or Locker depends on the year and the model of the vehicle. But the G80 code is used for both. By the looks of the unit it would appear to be a limited slip. I don't know what the G80 was in '99 but if I had to guess that is stock. If it was me and I needed to be replaced I would replace it with a truetrac if available for the axle.

All G80s installed in trucks were mechanical locking diffs with the exception of the quadrasteer which could have a G86 limited slip. Cars got the G80 limited slips.

G80 locker

ok so i bought a differential that looks exactly to that one! (g80 locker) almost brand new! for a very low price! took my truck today to the shop to have it installed and it turns out that the differential i bought has smaller bearings and there is no way to put the bigger ones that my truck needs! so i have to get another differential that will fit the bearings needed.. so now i'm wondering what to buy? right now i have a LSD... it works ok as long as one tire isn't in the air.. so i want something that works like the g80 locker but isn't as fragile, i mean whats the point of having a 6" lift with 35" tires and 4.56 gears if it cant handle a little off road???... i like the idea of having a rear locking diff but i don't like the idea of not being able to turn in corners without letting the gas so it can unlock... any help??