[azza4.2td]

Today I had the Patrol on axle stands and I noted when I rotated the tail shaft, both tyres roatated the same direction, not opposite like open diffs. I know it's an LSD but I didn't think they trasfered drive until there is some slip on one wheel.

I rotated one wheel and the other rotated the same direction and the tailshaft turned, so it didn't matter where the driving force came from, same result.

Lastly, I dropped one wheel on the ground and rotated the free wheel by hand. It was stiff, I could move it with some effort but it didn't freely spin.

Could this mean my LSD is:
1. Stuffed
2. Modded to be tighter
3. Oil getting old and due for replacement
4. wrong oil in it
5. the ramps (that compress the clutch pack) is "stuck" on
6. Perfectly normal and I should shut up and be glad I have an awesome LSD

Cheers

 

[Twinotter600]

6 but I don't know how much force it takes for one wheel stop and the other to turn.

Does it shudder when turning sharp from a stop, accel lightly on hard surface?

 

[azza4.2td]

There is a slight shudder. This is what I am currently trying to figure out. I don't think it is the clutch because it does it even when the clutch is fully engaged. I also gave all the uni's a squirt of grease and spin by hand but no binding there. Hence the only other thing is the LSD.

The shudder I get is usually experienced under hard acceleration, and even when turning a little. I think I have also felt it in a straight line, but I can remember.

It started after I had done some intense 4wdriving, in getting up steep loose surface as well as steep downhill ruts. I had a 500km journey to get home after the offroading and it seemed to be very noticeable when I pulled onto the highway after a rest stop, but it seems to have settled down. This is the reason for my LSD ramp stuck theory and wrong/old oil, it is worse when cold.

 

[Twinotter600]

When was the last diff oil change? The book calls for 140w.

 

[azza4.2td]

Unsure of when the oil was changed last. I have only had the car for about 5 weeks, and bought it privately. I doubt the previous owned would have changed the oil unless something was wrong. I did check the diff for water, but it wasn't milky. It was fuller than fill hole, and I let some out. It also had the distinctive gear oil smell, so I assumed it was ok. The oil was thin, not quite ATF thin but would be between the thicknesses of ATF and engine oil when warm.

I think I might change it out anyway, as I don't think it is thick enough.

Cheers

 

[azza4.2td]

Pulled the diff plug when I got home today. Well all I can say is that it had a lot of shiet on the magnet. the photo's below show it. The bottom one is shows it after I cleaned it.

Those spikey bits were the silvery grey material following the lines of the magnetic field, there were no solid bits of metal.

The stuff on the plug was very akin to graphite suspended in the oil.

The old oil had a shimery look to it so it looked like there was still some of the "graphite" in suspension.

It is possible that the magnet was full of this stuff that it could no longer hold onto anymore and the rest would have been floating around the oil.

I am going to leave this oil in for a few weeks or until the service after next, (in about 6000km), and then replace it again. I'm hoping the new oil will collect any of the left over "graphite" and stick it to the magnet.

My feeling is the "graphite" is the LSD plates rubbing and grinding off microscopic pieces of metal, and the chatter was because the oil was full of this stuff giving unusual LSD operation, possibly locking it up slightly.

Anyway, any comments are welcome.

 

[BeNos]

your shuddder would have been bad oil. limslip 140 is the bees knees for these things.
change that and it should all be sweet.
also that is pretty normal for the magnet of a diff.

 

[MikeH]

The proper oil is THICK. It's like honey on a really cold day.
If you use a funnel and a small hose it takes about half an hour to pour it in it's so viscous...
I it should be closer to grease than auto transmission fluid.
The best way I found was to put a nozzle on the bottle and squeeze it in.

I suspect someone has put normal diff oil in yours, possibly not even LSD oil. That was the case with my Mav when I bought it.
Get it nice and warm and drain it for about an hour then fill with the correct oil.
After a while it will get tighter as the incorrect oil in the clutches is rinsed out.

 

[azza4.2td]

Mike, the fact that it felt too tight was the my concern. The oil has now been changed and I hope I will have results soon.

It does appear that the oil was too thin. After driving home, I drained it and it literally rushed out so quick I could hear the air being sucked in through the breather, and it definately felt thinner than the new stuff I put in. I put in some Nulon 85W/140 LSD oil in. I have searched the forums and this grade of oil seems to be the popular choice with no ill side affects.

Now I am tempted to do my front but after reading the capacity, i'll need another bottle or drum more like it. Man diff oil (especially LSD) is expensive. Front might have to wait for another service.

 

[Twinotter600]

Now I am tempted to do my front but after reading the capacity, i'll need another bottle or drum more like it. Man diff oil (especially LSD) is expensive. Front might have to wait for another service.

Ha ha yeah it's a big sucker but no need for the $$ LSD oil....unless of course you have a pathy LSD up front.

 

[azza4.2td]

I couldn't believe, on my drive to work this morning, very little shudder to start with but by the time I got to work, I could not detect any shudder at all. I thought maybe it would take some time for all the bad oil to work it's way out of the clutch pack. Well I am surprised and happy that the problem is fixed.

What I am still confused about is that the Diff had only recently started doing this, maybe it was ok until it was used heavily which exacerbated the problem. The old oil is very dark coloured and full of the microscopic metal. Even if it was the right oil, it looked very old,

Just glad the LSD is still ok.

Cheers

 

[bigsim1]

i had this problom in my old hilux, did some asking around, apparently if its wrong oil it will shudder real bad, put the the recomended stuff in and she was like new

 

[ST391GQ]

MY factory workshop manual states that the correct oil to use in Patrol LSDs is straight 140 limited slip oil....not 80/140 or the like ...but straight 140LSD. I queried this with the local dealer...and the workshop manager said that he had been advised by Nissan Aus. that any other oil/grade of oil than that recomended was an immediate "NO WARRANTY!!"
I figured that was enough for me hey.

HTH.

Cheers Keith

 

[azza4.2td]

MY factory workshop manual states that the correct oil to use in Patrol LSDs is straight 140 limited slip oil....not 80/140 or the like ...but straight 140LSD. I queried this with the local dealer...and the workshop manager said that he had been advised by Nissan Aus. that any other oil/grade of oil than that recomended was an immediate "NO WARRANTY!!"
I figured that was enough for me hey.

HTH.

Cheers Keith

Problem is the Auto shop I was in (Supercheap) didn't have any straight 140. I have a '99 model anyway so no warranty issues and as I said, speaking with others the multigrade is fine.

 

[eighty8]

I think you'll find you have a good working lsd after doing the oil change. I've been playing with different shim thickness's lately, going from fully locked, to semi locked and shuddering, to end up with a combination that is as you have described with yours. With one wheel off the ground there is a bit of force required to rotate the wheel but it is not a free spin.
I have used the same oil that you have, on and offroad the unit works extremely well. Prior to shimming it was very loose and would easily lose drive.
I would change the oil again in 1000k's or so and then enjoy the famous Nissan lsd.

cheers.

 

[Twinotter600]

How many kms on your LSD prior to shim? What do the shims look like? A thin dsk the same as a plate?

 

[eighty8]

How many kms on your LSD prior to shim? What do the shims look like? A thin dsk the same as a plate?

Its got 350 k on it. The shim is just a copy of the plates.

cheers.

 

[Twinotter600]

Mine works very well but where ti get shims? From the parts manual?

 

[eighty8]

Mine works very well but where ti get shims? From the parts manual?

Actually mine is from the supermarket, made from a coffee tin.

 

[Twinotter600]

Ha, that easy eh! I will stow that info away for long time down the road....