LSD appears to be inop

I've got an '08 long bed with 95K miles on it. When I bought the truck back in March, I immediately changed all the fluids (AT, oil, front/rear diffs, & transfer case). I bought the gear oil for the diffs from the dealership, they recommended Castrol Hypoy C 80/90 and they gave me a tube of additive for the limited slip rear end.

Yesterday I was coming home from hunting and was on a fairly steep incline. One rear wheel began spinning and the other didn't kick in like it should with the LSD. In fact, the other wheel never spun at all. I put her in 4wd and made it out easily. When I got home I jacked one rear tire off the ground, put it in gear, and the only tire that received power and spun was the one off the ground. I checked for leaks in the rear diff and the fluid was still at the correct level.

Any ideas? Is the Castrol Hypoy C that I used not recommended? Like I said, the Toyota dealership sold it to me...

Thanks, Hogfan

 

Ah, I see. However, it didn't work on the logging road either.

 

That does seem odd to me. Sounds and acts like my older chey's. My rear seems to be very sensitive, it is forever pulling with both (I'm not complaining.) I wonder if in your case you could have tried slightly taping the breaks in hopes that it would activate the other tire (like in older chevy's?) I don't know if our trucks work that way.

 

well its easy to check if it is working (assuming your truck has one from factory. Lift whole axle in the air and try to spin one tire. In open open truck if you spin one wheel forward other spins backward. With LSD it does the same thing but it takes really hard force to do it. On my truck using torque wrench its around 150 ft-lb to spin them in opposite directions.
If it is easy then something is not right.
Those trucks have 8 pack LSD from factory so they have significant force even with one wheel in the air. Those LSD's are not the same as Truetracs installed in most domestic trucks. Truetrac is useless in the air unless you apply the brake. In ours no need for that unless its broken. How big was the tube with additive?
that Castrol looks like the right thing, do you know if it had own additive already?

 

I'll try spinning the rear tire. From what you're telling me, I shouldn't be able to turn it by hand.

The Castrol doesn't say anything about having an LSD additive already in it - I still have half a bottle in the garage. The tube of LSD additive couldn't have been more than 8 oz or so. I don't remember what brand it was or anything, just remember that it was an LSD additive that Toyota sold me. Maybe it wasn't enough...

 

So I finally got some time and jacked up the rear end of my truck (both tires off the ground). I could turn one wheel, with some force required, and the other would rotate opposite. I don't have a torque wrench, so I can't measure the torque. I did jack up one side and put it in gear. Same result as before. Wheel in the air would spin and no power to the other wheel (even tried the brake taping). I might try to drain the LSD like I did 15K miles ago and try a different oil and LSD additive...just to see what happens.

I suspect that the guy that put the 90K miles on the truck before I bought it might not have EVER changed the diff oils. Maybe the recent fluid change, along with another fluid change this weekend, will flush the gunk out of the plates and it will function properly.

Any thoughts?

 

I'm thinking about taking the pumpkin off and overhauling this thing...

...unless anyone has any persuasive words against me doing it...

Thanks.

 

Probably best option, you going have to replace clutch packs in there. Mark everything so you don't need to reset gears afterwards

 

I suppose dropping the drive shaft and diving in is the way to go.

Thanks for the advice on marking everything. There's a high chance that I would've have forgotten to do that until it was too late.

I tried to find some but failed - do ya'll know of any pics or step by steps that have been posted on doing this?

 

Follow FSM , The hardest part is getting carrier out. LSd itself is very easy.
There are tons of step by step for installing rear lockright or Aussie locker. That will show you how to pull carrier apart. Once you get LSD out its only few bolts. When you putting together use blue loctite on bolts.

 

Reading this makes me happy that Toyota changed to the TRAC limited slip system on all the trucks! Bummer you are going through this hogfan.

 

Yeah Dave, it stinks for sure. However, I would think that driving 90K miles on the original diff fluid (which I am almost certain is what happened with the previous owner), will render most LSDs useless, regardless of type. Could be wrong.

Anyone got any FSM pages on this subject for an 08? I looked at a Haynes manual, which I normally despise, and it didn't have a good description.

Thanks.

 

I fixed for you, You are Welcome

 

What's a mall? How about I teach you about the desert and Baja?

 

You are correct about that... I really haven't read of too many LSD failures in the '05 to '08 Sports!

Hope it all ends well for you!

 

Good one - both of you.

Thanks Blue.

Thanks Dave.

 

Blue, I've searched for step by steps for Aussie or Lockright locker installation and haven't found anything. Would you mind pointing me further in the right direction?

Thanks.

 

Here you go...
http://www.tacomaworld.com/forum/technical-chat/134446-how-richmond-gears-powertrax-lockright.html