differential not spinning on bench

[857lover 291]

so i took apart my differential it’s a 10 pinion ls and i put it all back together but i noticed that the axels don’t rotate and i don’t remember if they where spinning when i took it out is this normal ?

 

[Achto 27,601]

Your tranny should be a limited slip. That big C clip in by the pinion gears keeps the axles from spinning separately. It will slip (one will turn one way while the other spins the opposite direction). But it takes a fair amount of effort.

[857lover 291]

1 minute ago, Achto said:

Your tranny should be a limited slip. That big C clip in by the pinion gears keeps the axles from spinning separately. It will slip (one will turn one way while the other spins the opposite direction). But it takes a fair amount of effort.

so i won’t be able to spin those axels like as it sits because they don’t move at all

[Handy Don 12,235]

The whole point of LSD is that the axles do not rotate relative to the other

1 minute ago, Achto said:

Your tranny should be a limited slip. That big C clip in by the pinion gears keeps the axles from spinning separately. It will slip (one will turn one way while the other spins the opposite direction). But it takes a fair amount of effort.

Also, it isn't being bathed in oil as it will be when the trans is back together. With them dry now there is extra friction between the pinons and the differential body as well as against the spring.

[857lover 291]

1 minute ago, Handy Don said:

The whole point of LSD is that the axles do not rotate relative to the other

Also, it isn't being bathed in oil as it will be when the trans is back together. With them dry now there is extra friction between the pinons and the differential body as well as against the spring.

but neither side of axels spin i am just making sure that’s ok so when i put it all together it works out 

[Achto 27,601]

 

If I jack my LSD's up & lock the parking brake, it is fairly hard to get the diff to spin. At this point the tires help create a lot of leverage.

 

2 minutes ago, 857lover said:

but neither side of axels spin i am just making sure that’s ok so when i put it all together it works out 

 

As long as you put the pinion gears in the same way as they came out, it will be fine.

[TJ5208 1,824]

2 minutes ago, Achto said:

 

If I jack my LSD's up & lock the parking brake, it is fairly hard to get the diff to spin. At this point the tires help create a lot of leverage.

 

 

As long as you put the pinion gears in the same way as they came out, it will be fine.

May I ask what you mean about locking the brakes and the diff is hard to spin.

[Achto 27,601]

6 minutes ago, 857lover said:

but neither side of axels spin i am just making sure that’s ok so when i put it all together it works out

 

 Can you lock one axle in a vise and try spinning the diff? This would give you some more leverage to see if it will slip. Clamp in the center of the axle so that you are not near the bearing or seal race.

[Achto 27,601]

2 minutes ago, TJ Salyers said:

May I ask what you mean about locking the brakes and the diff is hard to spin.

 

 With both rear wheels off of the ground and the parking brake locked. When you spin one wheel, the other one will spin the opposite way. This is fairly easy on an open diff, not so easy with a limited slip.

[857lover 291]

23 minutes ago, Achto said:

 

 Can you lock one axle in a vise and try spinning the diff? This would give you some more leverage to see if it will slip. Clamp in the center of the axle so that you are not near the bearing or seal yeah i’ll have to check it out tomorrow 

[kpinnc 12,083]

1 hour ago, Achto said:

(one will turn one way while the other spins the opposite direction).

 

You got that backwards for LSD. The opposite side will spin the same direction but slower. 

 

If the opposite side turns the opposite direction, it is NOT limited slip.

[TJ5208 1,824]

Turn the wheel slowly.

[Achto 27,601]

7 hours ago, kpinnc said:

You got that backwards for LSD. The opposite side will spin the same direction but slower. 

 

If the opposite side turns the opposite direction, it is NOT limited slip.

 

Not really. It is still a planetary differential not positraction. The C-clip riding against the pinion gears just makes it harder for it to slip.

Edited April 6, 2022 by Achto

[953 nut 55,298]

10 hours ago, 857lover said:

i took apart my differential it’s a 10 pinion ls and i put it all back together

Did you torque the bolts to 35 foot pounds? Last thing you want is having a nut come off and the blot break an end plate.

[pfrederi 17,741]

A few years ago when we were researching getting replacement springs made I did some experimentation on LSD.    It takes some effort to turn the axle indpendently

 

 

[TJ5208 1,824]

6 minutes ago, pfrederi said:

A few years ago when we were researching getting replacement springs made I did some experimentation on LSD.    It takes some effort to turn the axle indpendently

 

 

MVI_0123.AVI

 There's no picture only audio.

[pfrederi 17,741]

1 minute ago, TJ Salyers said:

 There's no picture only audio.

Downloaded it and it worked on my computer.

[TJ5208 1,824]

Figured it out my phone doesent support it.

[pfrederi 17,741]

Also keep in mind your differential has the aluminum end plates.  They do not stand up as well as the steel ones.

[Handy Don 12,235]

1 hour ago, pfrederi said:

A few years ago when we were researching getting replacement springs made I did some experimentation on LSD.    It takes some effort to turn the axle indpendently

There are two important engineering/design decisions in the WH LSD differential that separate it from the other differentials:

 

1. The spring that pushes against all ten pinions. When the pinions try to rotate, the friction between the spring and the pinions resists that rotation. Because five pinions are rotating one way and five in the opposite directions, the friction is balanced and the spring itself does not rotate.

 

2. Pinions that float in the body (all other WH transaxles have shafts or the equivalent on which the pinions rotate). The LSD spring forces the floating pinions to rub against the inside of the body of the differential. This extra friction between the pinions and the body also makes the pinions resist rotating. (Imagine a brake drum being pressed against a brake band instead of the other way around.)

 

Pinions rotate ONLY when the two axles try to turn at different speeds! So when turning with good traction, or when one wheel starts to slip, or when both wheels are off the ground and you turn one wheel, the LSD provides resistance and tries to make both axles turn at the same speed in the same direction.

 

By the way, all this extra friction means the differential needs more cooling oil, hence the extra neck on the filler plug to increase the oil capacity. It'll also wear the spring and the pinions more quickly if driven with lots of turning or wheel slippage.

 

(Thanks and a tip 'o the hat to @stevasaurus. His videos, posts, and answers to my numerous questions helped me see inside that differential and understand it! Thanks, too, to the anonymous authors of the WH Transmission Uni-Drive Manual. What a wealth of information they provided.)

 

Edited April 6, 2022 by Handy Don

[kpinnc 12,083]

5 hours ago, Achto said:

Not really. It is still a planetary differential not positraction. The C-clip riding against the pinion gears just makes it harder for it to slip.

 

But when one wheel spins the LSD does turn the opposite axle the same direction. This is what makes it 'limited slip.' This can be verified with both back wheels in the air turning one side by hand.

 

The same 'test' on 4 and 8 pinion rotates the opposite side in the opposite direction. This differential is more or less nothing more than to allow easier turning of the tractor on hard surfaces. It gives no additional traction. When these diffs rotate inside the transmission, and one wheel slips, the other wheel does nothing.

[stevasaurus 22,764]

There is a little truth in all of these statements, but remember this...The Limited Slip Differential only acts like a Limited Slip when you are going in a straight line.  It acts like a regular differential when turning.  

[Handy Don 12,235]

3 hours ago, kpinnc said:

This differential is more or less nothing more than to allow easier turning of the tractor on hard surfaces

 

It is more.

It shares the available power equally to both wheels during the turn while also allowing them to turn at different speeds.

Traveling straight, with wheels having equal traction, it gives both equal shares of the power.

ALL of the WH differentials do these things--this is what planetary differentials do.

 

The misunderstanding is that the non-slipping wheel is getting no power. It is getting an equal share, but it isn't enough to turn the wheel! The slipping wheel's share is just spinning the wheel faster!

 

What does LSD do differently?

It internally diverts some power that would, in a regular differential, go to just making an already slipping wheel turn faster go instead to the gripping wheel.

So the question is, how to get the power from the slipping wheel to the non-slipping wheel. It is doable:

On a farm tractor, the operator manually applies a brake to the slipping wheel to take power from the spinning wheel and divert it back through the differential to the wheel with traction.

My Volvo does the same thing but with wheel speed sensors and electronically actuated independent wheel brakes (an extension of the anti-lock system).

Subaru's newer and more sophisticated technology can now divert nearly all of the power to the non-slipping wheel without using the brakes.

WH's LSD (circa 1966!) does it by making it ALWAYS easier for the two wheels to turn in the same direction at the same speed than to turn independently

 

Edited April 6, 2022 by Handy Don

[kpinnc 12,083]

1 hour ago, Handy Don said:

On a farm tractor, the operator manually applies a brake to the slipping wheel to take power from the spinning wheel and divert it back through the differential to the wheel with traction.

 

Exactly why I want turning brakes... 

 

And, not having them severely limits the standard differential's effectiveness when slippage occurrs. My previous statement should have clarified that. Thank you Don for your post!

Edited April 6, 2022 by kpinnc

[pfrederi 17,741]

Turning brakes on my D200 are less than impressive. Independent brakes on my Farmall M and narrow front equal right angle turns....

Edited April 6, 2022 by pfrederi