Beware changing LSD lube!!!!!!!!!!

I'm about to do the 30k maintenance on my '09 sport. Read through this whole thread and was getting worried since I was about to use Amsoil severe gear 75/90 to do my rear diff. Used it in my '01 with no problems but that was an open diff. Then I started thinking: Toyota switched to electronic LSD in '09 didn't they? Does that mean I have open gears and there is no need for concern about LSD additives? ELSD means the slip is controlled electronically from outside the gear box right?

 

Correct, you dont have to worry about additive.

 

I see this thread has been around a while..

When I had my diff fluids changed by the Toyota dealer last week, they said they are no longer using Toyota brand diff fluid because it costs so much, they are using Ford brand.. I hope it doesn't cause any problems....

 

Does that mean I will be fine with synthetic? I called my dealership and asked the service dept. They said to use 80W/90 and a tube of LSD additive. I asked if I really needed the additive even though it was ELSD and not mechanical. I have a feeling they really don't know either. They usually don't. I mean, I knew more about the truck and options than they did when I bought the truck.

 

Ok .. I had my dealer do the 30 k service.. I have 4x4 with Elect diff lock... They said it doesn't need change because there isn't a Limited Slip in the rear end.. I assume that is true... is it?

 

I would just go with Amsoil or Redline and see how it does. If it is noisy or vibrates then add some friction modifier, but probably not necessary with a brake actuated diff rather than mechanical clutch LSD.

 

yeah with only 30k I would assume your fine. if your concerned or if you've dunked it in some deep water you could drain some and just have a look. you could probably even used a syringe type setup and open the check plug and with a short piece of tubing attached draw some out and send a sample to Blackstone for analysis.

 

You still need to change the diff oil regardless of what kind of differential you have. Open diff, LSD, locker.....you still need to change the oil.

The dealer told you that it didn't need changed ??
If you have a mechanical LSD - it needs friction modifier. All other diffs do not need friction modifier.

 

Dealer probably misunderstood year and they think you have mechanical LSD. Thats all. You can use pretty much any oil you want.
So any synthetic you want. and no additive unless you want to add some..

 

Awesome - that's what I thought. Thanks. BTW - BlueT, how's it going? Do you remember me from NTC. Red '01 tacoma - live in Cheshire. The '01 is gone now, traded it for the '09. You still wheel with NTC? Do you still have the LC, 1st gen tacoma and 2nd gen tacoma?

 

yep still with NTC and still rolling LC . It purrs like kitten, With 180k miles engine sounds better then 2gen truck.
BTW if you need help just stop by ...

 

OK, I've called a half dozen toyota dealers in the area and they all say you still need to add the friction modifier even for E-LSD. Some seem to know what they were talking about and others not so much but not a single one said you don't need it. I think I might just go with Valvoline 80W-90 with the additive and skip the Amsoil for the rear just to be sure. Got about 400 miles to go before the service - so next weekend I guess.

 

Its simple thing to check. Do you have a sticker on the rear diff that says "LSD oil only" if not then you dont have mechanical LSD. It also should be listed on the vehicle purchase sticker. If both dont have mechanical LSD listed then you can use whatever oil you want.
If you still not sure stop by my place on Sat and we will check.

 

I've used Redline 75W90 without adding any additional friction modifiers and have had no issues. I did this in both my '06 Tacoma TRD Sport and my wife's '05 4Runner both with the LSD sticker on the pumpkin. The Redline description states: "Contains additional friction modifiers for suitablity with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required"
I bought a bottle of their friction modifier but did not have to use it on either vehicle as they both run great without it. Been about 1500 miles on both and been quiet and smooth so far.

 

You do not need friction modifier for the AUTO LSD.

How exactly did you ask them (in words) and who did you ask?

Call them back and ask a TECH. Not the first person you talk to on the phone. Not the Service writer. Not the Service Rep, Not the Service Manager. ASK A TECH
Make sure you fully explain to them exactly what you have. If they need - give them your VIN number.

 

You can add I with friction mod even in non LSD without a problem so be safe

 

Just a thought: I know I've read remarks earlier in this thread indicating that the friction modifier increases lubricity. Do we know for sure if this is the case? A clutch-type mechanism needs friction to work properly. Is it possible that synth lubes are too slick and the additive is to promote friction, ie decrease lubricity slightly so the clutches can grab properly when needed? I realize I am most likely wrong on this issue, has anybody done any research on this subject?

 

Friction modifier is a SLIP agent. It promotes slippage. Without it, there's TOO MUCH friction and why it chatters when turning.

When both wheels are spinning at the same rate/speed, the clutches ARE grabbing already. Its when you make a turn, they need that friction modifier to allow them to SLIP (or stop grabbing) while in the turn. Obviously, you can make the turns...but the clutch continues to grab slightly while you make a turn. The friction modifier allows it to slip.

 

So what's the difference between mechanical LSD and electronic LSD? The way I understand it, mechanical has clutches inside the differential gear housing that come in contact with the gear oil and electronic uses sensors that measure wheel spin which in turn controls braking at the wheels. If that's correct, does that mean there are no clutches in the gear box for electronic LSD? Shouldn't matter whether the oil is synthetic or dino or has the additive or not, right?

 

great explanation Jan, thats basically what I figured. even with the Redline and extra additive I get a trace amount of groan when I first take off, so I was entertaining the possibility that the modifier caused stickage instead of slippage. the sound is so minimal that I'm sure its not unhealthy, just being paranoid I guess. I have entertained possibly trying some Amsoil while I'm pissing away cash for lube, but I probably hold off for quite a while.