LSD Problem, maybe. Someone Diagnose what's going on!

Update: Tech said that it was the additive. Or, more specifically, the additive was either not getting where it needed to be or not doing what it needs to do. He explained that if the additive is not getting in the friction plates that you can get viscous coupling in the plates and they stick together and act like its locked, not letting it slip, causing binding. I can buy this. He said that the weight and brand of oil is not really that important, but that our rear diffs are really finicky with anything other than the toyota or chevy additive. Anyway, they replaced the oil and additive free of charge and wrote it as a warranty claim (I stressed to him that I had replaced the rear diff oil and additive TWICE). NO MORE NOISE COMING FROM THE DIFF!!!! FYI, the dealership used

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90. Proof:

 

glad to hear the problem is gone and even better covered under warranty.

 

X2!! I'm glad they even went with

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90!!! Thats all I have in my garage. I'm a little concerned still cause mine is all Redline products. Redline oil and redline LSD additive.

 

Can you get from them what brand oil and what brand of LSD additive they used ?

 

Went through this problem my self, spoke with the head tech at a local dealership and he said they use the posi-trac additive rated for Chevrolet differentials. Worked like a charm.

 

When I went to buy new crush washers for my rear diff, the parts guy told me they used the FORD additive. I just asked where the closest ford dealer was and he told me that they sold it there. Motorcraft Friction Modifier LSD Additive cost about $7. The parts guy said toyota does not have their own branded additive. At my local dealer, they use shell dino oil.

I had the similar symptoms and recently switched out to the Castrol 80w-90 oil with FORD additive and haven't had any problems. I did a lot of reading on the forums as well and it seems like either the FORD or GM stuff is the way to go.

 

75-90 will work and give long service however here would be my concern for those applications which are above and beyond the normal requirements.

gear boxes/drives/FD work by transmitting power. In some applications the power delivery is consistent and does not vary much but in an automotive application it is a different story for the following reasons.

1. Shock loads
2. Shear stresses
3. heat

This is a text book case in an EP application where the following become critical and are what deal with the above mentioned issues.

additives both sacrificial and non-sacrificial (we will get back to that latter) and film boundary layer which is directly proportional to viscosity deal directly with the conditions above. Like i said before 75 to 80 is greater than the difference numerically there is between the two. there can be as much as double the viscosity between the 80 and 75.

Now under normal conditions the difference is not much of an issue. however for those of you who operate in high ambient temps is some reason to change since the oil will get thinner as the heat goes up – a straight 90 is best for that application as opposed to a multi viscosity oil – more stable but the benefit is probably negligible for this application. However, the biggest and most critical reason is that while towing and loading the truck all the above (shock loads, shear stresses and higher heat) becomes more of an issue and youll definitely want as resilient a film between the meshing gears. Also 4X4ing is a severe application (depending how aggressive you are)

One other thing to consider and I am just throwing this out there based purely on anecdotal info from what I have seen in other shops. It is much easier and cost efficient for a dealer to stock one oil as opposed to several varieties. They know 75-90 will work but that does not = the best option. I have no idea if that holds true in any or all the cases.

Sulpher == EP properties = bad smell

Other EP additives work only when there is metal to metal contact between asperities (micoscopic high points on the metal surface that comes into contact with the opposing metal surface). These sacrificial EP additives will be consumed/come between the metal to metal contact to avoid a weld at the point so they get consumed and thus not damage the surface of the metal

High viscosity = EP properties



Yes I am bored – stuck in DFW waiting for a flight.

 

Makes sense to me.

 

While this thread seems to be poplular....

Anyone ever use Amsoil Severe Gear? It's a

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 oil with additives already in it. We put this stuff in our corvette which has an LSD in it. Been working GREAT with no issues.

Wondering if this stuff will work in the taco.
API GL-5, MT-1, MIL-PRF-2105E, Dana SHAES 234 (Formerly Eaton PS-037), Mack GO-J, or the differential (hypoid) gear oil specifications from all domestic and foreign manufacturers such as GM, Ford and Daimler Chrysler. Can also be used in axles where an API GL-4 lubricant is recommended.

I might just get this and cross my fingers. We'll see. I've got about 4,000 miles yet till I reach 30K. Maybe this fall I'll do it.

 

You need to replace LSD oil at 15K .... so you are way overdue, dont wait for fall.
On the side note, that LSD is the most picky thing I ever encountered. I seem to have problems finding oil & additive that works with it. So far the only thing that worked with 0 problems was Valvoline 80W-90 with Trans-x additive.

 

Yeah -- just bear with me. Ive been caught with delayed flights in various airports. I have no one else left to bore the hell out of

 

maybe thats why is so hard to find additive that will work with

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 but anything seems to work fine with 80w-90.
BTW none of the synthetics gives long lasting run on that LSD. The best I got was little over 3 months of grind free, afterward, GRRRR....... sound would come back

 

definitly possible. Get some of the 75 & 80 and the synth. Pour each out and you will devinitly notice a difference. The 80 will flow noticibly slower. It's thicker and that may be a factor. What is very strange is that it works for some and not for others. Maybe Toyota uses different suppliers for the internals or some lots where slightly out of spec of manufactured silightly different to save cost. Unfortunately no one on this site will be able to definitively say one way or another. As such the 80 is fine with it and not the 75

Sorry -- should have said the synth is slicker Than the other two. That is why on some dirt bikes most of which have wet cluthes it is not recomended to use a synth oil. That makes your theory even more plausable. If I was a betting man I'd say that was the reason

 

I've got a third member with an Eaton LSD in it that I need to install so I've been researching the type of gear oil and additive needed for the it. Eaton has been less than helpful by only recommending that a quality mineral based gear oil be used with friction modifier.

After doing some digging on bobistheoilguy.com it seems that the Eaton LSD's (which is what is in the Tacos, right?) were developed with Shell and Texaco conventional oils that met a spec set by GM/Ford. It seems that most conventional oils work ok with them, but synthetics with built in friction modifiers are a no no. Something about how the synthetics don't bond to the clutches as well.

It doesn't surprise me that Toyota service uses GM/Ford friction modifier. Although the CRC modifier I bought says on the tube that it meeds the specs set by GM, Ford, and Chrysler so I guess it's ok to use.

 

Its probably how they mix oil Groups to get certified for a spec. There is lots of room to make different mixture maybe some

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 are so crappy that they are actually 80w-90 Dont know that but I am very interested why that LSD refuses to work with synthetics.

 

O.k so can someone pick top three oils to use in our LSD diff with viscosity #, because I have Royal Purple in there and it's ssttuudderrriing, and it's starting to piss me off because I spent $$$ on that crap that I DON"T RECOMMEND to anyone with LSD. AVOID Royal Purple in the LSD Diff!! I do however use Royal Purple in the engine, no problem!!

 

I know that regular Valvoline 80w-90 with Trans-x additive works . not sure about others.

 

Valvoline

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 with Trans-x did not work in mine
Castrol 80w-90 with Champion LSD Additive did not work in mine

I think the Oil is not the important component, I think the Additive IS!

 

That's why I am not a betting man. It sound like the oil is not an issue.

May be supplier issue Or the additive issue but if I remember correctly there are some folk who use the run of he mill stuff with no problems -- who the he'll knows. At least there isn't a Prius throttle cable attached to it.

 

why? did something happen with the Prius?