Trying to figure out my sierra diff. I've worked out its 7.5 in and a 3.92 but can't figure the little plate to see if its an LSD or not. Don't really want to take cover off.

When I have the car jacked up so both rear wheels are off the ground. If I turn one of the wheels the other one turns as well.

What does that indicate?

 

have 1 wheel off the ground and try to turn the nose drive or the opposite drive flange

 

So have one wheel off the ground and try to turn it?

 

You have an LSD, if the opposing wheel spins in the same direction.

Martin

 

yes, with the car in gear not running

if it is an LSD the wheel will be very tight to turn, if you can turn it!

same check with a diff on the floor,
hold one drive flange so it wont turn, turn the nose drive and if you struggle to hold the drive flange still, its LSD, if the opposite output flange turns freely while nose drive is turned, its and open diff

 

not always the case, it must "turn the same way" when forced under load

lots of vehicles when both wheels are jacked up will turn both wheels in same direction, with no LSD



this must always be checked under specific conditions, incase of badly worn LSD`s or tight open diffs

 

With one wheel on the ground and car in gear it's near impossible turn the lifted wheel. What's that mean then.

 

It will be because you are trying to turn the wheel, which is connected to the diff, which is trying to turn the other wheel, which is on he ground, so then it will try to turn the prop, which will try to turn the gearbox output shaft, which is geared to the main shaft, which is connected to the input shaft, which is held in place by the clutch, which is connected to the engine

So you can move the wheel to take up all the slack until you are then trying to turn the engine with that wheel

If you are not in gear the output shaft is not locked to the countershaft in the box so both will rotate freely and let you turn the wheel

 

Hi
I recently took my diff out and replaced radial drive shaft seals
to do this i sat it on its side and knocked the seal in - both sides
now when i try and turn it by hand it turns then seems to jam ?? turn it back and rotates but then also jams later ?

could i have knocked something loose ?

thanks