Help to confirm diff ratio

[jcote75]

HI,

Wanted to check what gear I have in differential this morning.

So I started to block one half shaft with a bar and attempt to turn the other side half shaft........ I did all I could but it would never turn. Not even an inch....

So I've removed the bar from the half shaft and started turning the two half shaft together 10 turns. Result on the drive shaft is 41 turns.

Can I confirm I have a 4.11 gear?

Since I wasn't able to block on half shaft, is this related that it could be a LSD unit?

If I refer to an old invoice (early 80), it should be a 4.11 R200 with a LSD. But nothing on the differential can confirm me that.

Can someone help me on this.

Thanks,

Joce

[Zedyone_kenobi]

it really depends. Most LSD have a break away torque that will allow one side of the diff to turn at a different speed than the other. How hard did you try to turn it?

its not uncommon for some people to make a 'poor mans' differential by welding up the cogs inside of it.

[JeffMopar]

jcote75,

That is how you verify the axle ratio. Turn the tires one revolution and count how many times the driveshaft turns. You compare that number to the available ratios for that axle to find the exact one. Going ten times is far more accurate though. Not sure on the limited slip diff part.

[Walter Moore]

Most of the LSD differentials that I have owned on non-Nissan products took more force to override than normal people would be likely to apply by just trying to turn one wheel by hand. If you were just trying to turn the studs without the wheel you would need a breaker bar to move it.

Just my opinion.

[zguitar71]

Take the rear cover off the diff and look at the carrier, this will confirm if it is an lsd or not, you can also check the ratio stamp on the ring gear too. But if you cannot turn the wheels seperatly and you have a receipt that said it is an lsd then it probably is.

[jcote75]

Thanks for the advise.

I'll open the cover in a few weeks to what it is actualy.

Been installed almost 30 years ago, so could have been change since.

I have a receipt that there is a close ratio 5 speed from Datsun Comp and it appear it is true. So probably the same thing fot the differential.