Fuso Rear limited slip differential

[jappie]

In september, I bought my Fuso 4x4 ( u.s. FG40, FGB72... ). I did not have time to play with it because it went to storage as soon as the snow came. So today I went to start it for the first time since October, got it out on ice and tried the 4x4. Got in reverse until a snow ( ice ) bank stopped me. I could see by the rear window the left set of wheels joyfully spinning while the right set was not moving, same in the front. Now I thought the rear differential was not suppose to do that.
Is that Normal ? still a newbie at this
JP

 

[jappie]

ok, I just found this on the net:

"...... but even the most powerful clutch-type LSD needs some wheel grip on both half shafts to function.
With one wheel clear of the ground a clutch-type LSD is no more effective than an open diff.....:

So i guess being on very level slippery ice, is the same.......
and I have no rear weight, just the frame.
JP

 

[Howard70]

I've not had that problem our Fuso, but several of our toyota trucks with limited slip would work better when applying a little brake if one drive wheel was off the ground, that might have simulated the "some wheel grip" you mention.

Howard

 

[pugslyyy]

My experience with the Fuso limited slip is that it is really tight. I've never felt like I needed anything more. Maybe somebody changed the diff fluid and left out the limited slip additive?

 

[SkiFreak]

Maybe somebody changed the diff fluid and left out the limited slip additive?

From memory... if you do that it gets even tighter and makes undesirable noises when going around corners.