useless lsd

[muvit madness]

hi can anyone shed some light on my LSD it feels as though it might as well
be an open diff. i was articulating on a dirt hump in 2 wheel drive to the point
were 1 rear wheel broke traction & did you think the power transferred to the
wheel on the ground? NO... the wheel in the air started to spin & i was going
no where so i drove home jacked up the rear (both wheels off the ground)
turned one wheel clockwise why the other spun anticlockwise but slight force
was needed to turn it whilst in park &no handbrake applied. ithen dropped it down
& replaced the diff oil with castrol EPX 80w90 manual but havent taken it for a drive
as yet. just wandering if its time it needs retightening. does other mu limos act
this way when jacked up & both wheels are off the ground?.
cheers for any help.
muvit

[pig75]

Sounds like you have a open diff not a LSD. When you turn one wheel the other should turn the same direction

[muvit madness]

i realize that but 100% sure its LSD i know this because i changed it myself & when the 2 are together
the open diff you can see all the gears in the hemisphere & it has the cross bars in it when you look thru
the side where the shafts go in. where as the limos hemisphere is completly closed. e.g like a lockers one.
but thanks for you imput anyway.
cheers
muvit

[geeves]

Wrong oil for starters. Of the castrol range you need CASTROL LSX 90 but there are other good lsd oils. A few of us are useing penrite limslip with good results.Redline synthetic limslip oil might rejuvinate the clutches but costs a fortune.
The only question left is how to get the old oil out. First ring your favorite oil companys help line and ask for advice They are the experts (maybe) If you cant get a better answer try this. It is what I would do but I have not tryed it and will not garrentee results at all. Drain and refill with kerosene. Jack both rear wheels off the ground and rotate each wheel a couple of dozen times in each direction by hand. Dont even start the motor with kero in there With no lube you will kill the diff. Drain and leave open overnight to dry as much as possible. Fill with the correct oil and hope for the best.
Dont expect a lsd to act like a locker It needs some traction on both wheels to activate the clutches so wheel in air means no go to the wheel on the ground

[muvit madness]

damn it this is the oil that was recomended for my nissan patrol rear lsd by repco i just figured it would be all right to use in the mu diff should i drain it out of the patrol as well you think? as this is out of their manual.
regards
muvit

[pig75]

If you know it's a LSD then I would say the clutches are buggered, 35" tyres would put a big strain on the driveline it might be time to fit new diffs
p.s I use Castrol SAFXA in my LSD's, which is a synthetic oil if you use LSX 90 you should use an additive

[muvit madness]

last time i go to repco for advise is SAFXA suitable for my patrol rear lsd & front ARB locker do you think?
regards
muvit

[pig75]

it will be suitable for the air locker as we are castrol agents i will check at work tomorow about the LSD, what model patrol ??

[muvit madness]

gq patrol y60 exact year unknown. maybe he was right in recomending it for the patrol & it was just my BAD for assuming it would do the mu limo as well
cheers
muvit

[roga]

I had the same problem with mine
So I talked to a mate who uses a y60 patrol off road and he gets his own oil made up !
It is 140 viscosity with extra lsd additive ??
I tried it in my Mu and now the diff is working way better so it works
but I think I will strip the diff and shim it in the long term.

[mudgrip4]

Can't comment on other lsd oils much but the penrite limslip is inexpensive - about $25 for 2.5 litre bottle - and works well. However, don't use the lighter grade 85w90 limslip - more for cars and vans etc, but always use the heavier duty 85w140 - gives more bite and is more designed for off road use. Maybe Roga (above) had the wrong grade lsd oil initially.

The best oil for limited slips is the american Redline Heavy Duty Shockproof gear oil - used in race cars and dragsters etc. Makes the limited slip bite like hell, and clunk and rumble a bit, but it is expensive at $22 per 900ml bottle club price - not good if you have to regularly replace diff oil. The slightly lighter grade Redline is 85w140, same price and also excellent, and better if you have already had your lsd tightened up for off roading - the heavy duty shockproof becomes too noisy in diff then.

If you can't get much joy with your present oils, I'd flush diff as above, then put in 85w140 Penrite Limslip, run it for several hundred ks to clear off other oil residues from surfaces, then jack up and test again. If penrite lsd oil - a good one - brings no improvement, then it will be a mechanical problem with the lsd. It will either need major tightening, or repair.

Mike.

[geeves]

Ive been useing the penrite 85w90 limslip for 2 years with no problems. With a wheel jacked up you can turn it by hand but its an effort (torque wrench on wheel nut indicates about 70 foot pound when it slips) but this is enough to leave 2 black marks if you use to much throttle on a tight corner.

[pig75]

GQ LSD diff should have LSX 85w/140. SAFXA is a 80w/140 and should be fine.
the range goes
LSX 90 normal use
LSX 85w/140 heavy duty
SAFXA extreme duty and race applications

[muvit madness]

hi
just changed the oil in mu diff to the SAFXA at the cost of $33.50 p/L thank god it only drank 2 Litres i'll try & take it for a burn through the week if i can finish early enough. how long do i need to drive for to know when the oil will have reached its full potential in the limo? coz its a 20min drive to the 4wd park & was wandering if it would tell me if it was the oil or she needs to be retightened?

pig75: so its safe to say LSX85/140 in the rear gq diff & the EPX 80/90 in the front open diff with ARB air locker is ok? or be done with it & just use the LSX in both? as long as its a 85w/140 correct?just a matter of choosing a brand.

many thanks too geeves,pig75,mudrip4 &roga for your advise.
regards
muvit

[muvit madness]

oh yeah cool avatar their roga i found myself clicking the X & CANCEL to see if something would change,
good for a laugh ;D ;D

[mudgrip4]

Diff shop who did my tightening and sold me the redline said run the new oil in lsd for a few hundred ks to ensure old oil film gone from parts. Then test.

[muvit madness]

mmm geuss i wont be hitting the track any time this week then did he say anything about removing the oil as well to ensure all existing residue was gone then replacing it again with fresh stuff?
muvit

[mudgrip4]

No - normally drain old oil properly by jacking up rear axle on one side to ensure everything runs out drain bung which is slightly off centre on diff bulb. This did the job for mine, and after 3-400 ks when old film residues had worn off there was full effect of new lsd oil. If you want to be sure you get rid of all old oil, you can flush with petrol or kero as geeves suggests above. Only make doubly sure you have drained every bit of petrol out! Use compressed air if necessary to blow out every trace.

If the SAFXA you have put in already works well for Pig75's truck, a little bit of old residue shouldn't matter much. Check your lsd out in a few hundred ks and it should be clear if the lsd is mechanically ok or not.

Mike

[geeves]

A little more digging after my last post suggests no need to flush. The lsd oil apears to be standard GL5 spec oil with an additive for the clutches. This means that as long as you drain as much as possible you should be ok.
Try giveing the car a good thrash for 20 k or so then remove bung while hot and let drain overnight lift one wheel as per Mikes suggestion to drain even better

[pig75]

muvitmadness said:

pig75: so its safe to say LSX85/140 in the rear gq diff & the EPX 80/90 in the front open diff with ARB air locker is ok? or be done with it & just use the LSX in both? as long as its a 85w/140 correct?just a matter of choosing a brand.

EPX 80w/90 is fine for the front but if it was me I would use the same oil in the front and rear just for convenience and less likely to put the wrong oil in the diff.