[SoCalSerg]

Hi y'all. I have an 04 silverado ls 1500 crew cab 5.3l coil spring suspension, and was wondering how I could tell if my rear end has lsd or not. I want to change the rear diff fluid but dont want to buy the wrong type if its lsd. Any advice??!!

 

[j cat]

your diff should have a tag on it at the fill hole. using your vin# the GM dealership will have the build info. in the glove box is the build code info also to determine what you have. since people screw with these items jack up one rear wheel .. spin the rear wheel many times . the diff if a eaton locking diff will lock ....these type diff's are locking when one rear wheel spins the other not or at a lower speed of rotation...

GM also used a limited slip for cars. this type diff is limited in its locking since it has clutches not a lock. therefore this type will have slippage and also be constantly in this mode ... the eaton locker will never lock or operate unless the rear wheels rotate at different speeds.

when replacing the diff oil you must remove the rear cover and clean out all the metal sludge. also inspect gear teeth for cracks and wear marks . magnet is on cover clean it all with mineral spirits / paint thinner ...

2WD will have both open and eaton locking. 4WD is eaton locking.

 

[RayVoy]

A true lsd is not used in the full size trucks, they may have a mechanical auto locking gear set. Either way, use synthetic gear oil, not lsd gear oil.

 

[SoCalSerg]

Ok thank you both for your input it is greatly appreciated!