LSD ?

[RichR]

I have an 02 Tundra 86k with LSD rear.
I noticed when it was cold it was sluggish at start.
And I got stuck on ice easily.
I went to grease it today.
Rear jacked up in nuetral to turn drive shaft.
It did not free wheel like earlier.
And the opposite tire did not spin in the same direction either.
Is the clutch LSD shot?
What will happen if I leave it alone?
Any damage?
Should I look for a mechanical replacement?
This is a pavement truck/daily driver.
Kids and wife will drive so I need a civil acting rear.
Any idea on cost?
I live in Chicago so 4x4 shops are not plentiful.
Thanks for any advice.
Rich

 

[RichR]

Also recently switched to Scheaffer's #267 for Mobil 1.
Too much Moly?
Grasping for straws?

 

[Merkava_4]

lysergic acid diethylamide?

 

[JHZR2]

I can't imagine a toyota differential to go bad so early unless abused... toyota can do no wrong, it seems...

My father's LSD in his 94 previa has 205k miles and is just a slight bit noisy... we've been running royal purple in it.

and, IIRC (I may be wrong on this, I always confuse it), when you spin one wheel, the other SHOULD spin in the OPPOSITE direction on an LSD - so I think youre OK there (you wre worried they werent both spinning the same way). Of course I may be wrong - so dont go off of what Im saying here...

Did you use a heavier gear lube? 75w-140 in place of 75w-90 for example? That could do it...

Are you sure you installed enough?

Diffs are generally bulletproof unless they ingested a lot of water or were abused. It doesnt sound like yours is either of those two...

Can you remove the cover? Did you recall anything funky (e.g. lots of metallic shavings in your drained lube) when doing the change?

JMH

 

[Sparkman]

When you spin one wheel the other should go the same direction on a LSD. Effectively one side "drags" the other along via the slip clutches or viscous coupler. Does Toyota recommend a friction-modifier additive or special lubricant for their LSD rears? Sometimes using the wrong lube can cause these to act up.

Are your rear tires similar enough in circumference to avoid damaging speed differences?

 

[CBDFrontier06]

Definitely ask Toyota about what oil is required. Oils with friction modifiers could be the culprit, and can actually cause the clutch to wear itself out. I'd have them maintain that LSD for you, or at least use their products or products they suggest.

 

[Benzadmiral]

(Flashback to the '60s
Wow, man. . . .

Melts in yore brain, not in yore hands, man. . . .

(Back to 2007
Oh, wait. Limited slip differential. Ah. Never mind.

 

[unDummy]

You got stuck on ice? Did you use 4wd?

Spinning a wheel up in the air is not a way to test any LSD.

If there are no broken parts, nothing will happen if you leave it alone.

OEM LSD's have relatively low LSD capability. Many have very low torque ratings and slip too easily. Once you exceed that rating, it'll just slip away.

So, change the gear oil. If you want, use a gear oil with no LSD additive. Then, add just enough LSD additive to make dry street driving acceptable. Add only enough additive to reduce the LSD's chatter, groaning, & noise. The goal is to add as little LSD additive as possible to give the LSD as much grip without chattering away.

If you want a better LSD, you need to buy a new diff. You'll have to research your vehicle. But, eaton, TRD, Kazuma, Kaaz, ARB air locker, powertrax, detroit softlocker, and truetrac, are some brands worth looking into.

 

[BOBISTHEOILGUY]

grease has nothing to do with your problem, therefore there is no such thing as too much moly. moly only works with heat and cools down the parts then the rest of the moly passes by the heated (which is treated with moly) area and as it gets hot again as moly gets scraped off new moly will take its place. otherwise moly just goes by like any other suspended additive.

 

[SteveD2]

Not to be a naysayer, but different brands of oil CAN and WILL change the characteristics of the LSDs effectiveness. You get a super slippery synthetic in a Dana LSD, and they will not grab as hard no matter how much additive they claim or you add, I know this for fact (and RP is one culprit I have dealt with in the Dana's). Just changing brands of oil can make a difference. The same goes with the newer Trac-Rite LSD in the dodge AAM axles...it worked horribly with OE and Mobile 1 fluids, but works great with RP (but it is a different type of LSD compared to the Dana).

The "spin one tire this direction and watch the other" trick works on some LSDs but not all. The older clutch type dana and eaton rears would typically spin both tires in the same direction when the clutches were good and in opposite directions when the clutches were worn. However, some of these newer "gear biased" LSD (eg. the AAM Trac-Rite found in the 2003+ dodge ram 2500/3500) act like an open diff all the time unless there is similar traction under both wheels (the biasing effect). So the only way to know for sure is to pull the cover. And I'm not sure what the toy's use, but I believe it is a gerotor-type???

There are very few LSDs that can handle the "one tire on ice and one tire on pavement" scenario. There are only two factory-installed LSDs that I am aware of that will actually grab enough to push a truck in that scenario (the Dana 60/70/80 Power-Loc and the Dana 80 Trac-Loc), but at the same time they will also drag tires when cornering on bare pavement and push straight in slippery conditions because they are so agressive. Additionally, the clutch-style LSDs have a finite life span, typical less than 150k. the gear-biased LSDs theoretically should last the life of the vehicle. And because the LSD is less agressive (less likely to cause an accident) and a "non-wear" item, manufacturers are switching to them.

And I would not recommend a locking type differential for a daily driver application...been there, done that. Unless you offroad, a quality LSD will be a better choice...

steved