TRD sport LSD gear oil

So I've combed through all the discussions about diffs and oils, dino vs synthetic weights and brands, cons and pitfalls and I still have some concerns.... maybe.

So I have an rear LSD in my 2008 TRD sport and Im getting some chatter and locking up when turning. I've only had the truck a for a couple months now.. just under 78,000 miles on the odometer.

I'm leaning towards putting 80w90 dino in there, Lucas, or after doing some more research Im also considering Pennzoil 80w90, along with an LSD additive. I would use the additive no matter which brand I go with.

One thing I'm still wondering is since I have the lsd with the friction disks, how would using a gl-5 rated oil affect the diff and?

Has anyone tried that and is there anything I should avoid doing?

I havent tested the diff with the torque wrench 150lbs test... i hadn't read about that when I had the truck on the lift but the wheels spun the same direction and I have good traction in 2wd....I have a very steep incline, I live on a private road and I made it up in the snow and ice in winter very easily most days. Keeping in mind all of this... the low mileage, the traction, the fact that both wheels turn in the same direction and the chatter around turns leads be to believe that there is still plenty of material on the friction plates. The only issue is the chatter.

So what do you guys think?

Stick with dino as suggested by ECGS? (and some others)

Or synthetic? any issue if I use GL-5 because of the friction plates?... or is that only an issue for syncros?

I'm thinking to throw in 2 quarts of 80w90 most likely Pennzoil along with a quart of 75w90 synthetic Pennzoil again, along with an LSD additive 200-250ml. Up until yesterday was leaning towards the Lucas in the same weights and types.

Any thoughts would be appreciated... still not even clear as to what the LSD additive does... In theory it should make things a bit slipperier (to avoid chatter) but some here seem to be under the impression it creates more friction.

Any input would be greatly appreciated... especially first hand experience with a mechanical LSD in the early TRD sports (2005-2008)

Thanks in advance

 

I don't give mine much thought, maybe I should. I first used Mobil1 syn 75-90, then switched to Valvoline syn 75-90. I’ve never used the additive. Yours sounds like the friction plates may need replacing. I have no experience with that. Not knowing what is in there, I would put in fresh fluid (full syn, or regular with the additive) and see if that helps any.

 

So you've never had any issues with your lsd?

Thats good information. There are a couple of gear oils with additive for lsd actually added but a lot it seems are only "compatible" and it's written on the bottle which can be confusing.

When I see what comes out when I change the oil I will at least have an idea what's going on.

Hoping I wont have to change the diff but if I do I will stay with a lsd because if I add a locker even, unless its engaged it will be an open diff and not even have the brake assisted traction distribution. Which is why Im doing as much research as possible before changing the oil.

I wanna get it as right as possible as I can.

 

If your getting chatter occasionally & both tyres pull under power, dif should be fine.

I would go dino & a bottle of friction modifier in diff, once changed to new find a parking lot or open space and do about six or seven figure eights, that will work the modifier into the plates.

 

I tried the synthetics that claimed to work, but they all caused chatter. Went back to Vavoline

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

75W-90 with a friction modifier and all was good.

 

That's what I figure, if there's enough material to cause chatter there's enough to lock up both wheels. And both wheels turning the same direction on the lift points to this as well.

Thanks for the input.

 

Isn't Valvoline 75w90 a synthetic?

 

They have a non-syn formula called, “Daily Protection”. I think it used to be called “High Performance”.

 

Thank you

I found it. It's also available in 80w90. I think thats the first non synthetic I've ever seen available as 75w90. I took it for granted that no one made non synthetic gear oil in 75w90 grade, it seemed every dino oil was 80w90 and never 75w90. I just learned something.

 

Redline 75W90 in mine and good to go with no need for additive per Redline.

 

Can't go wrong with redline sure... thanks for the input.

I used that in my wrx with a lsd and I remember it mentioning on one of the bottles, either the 75w90 or 75w85 cant remember which but one of the 2, about chatter in lsd diffs. I dont think the subaru diffs are the same I'm not sure there are any wear parts in them so Im not sure it applies... but I remember that about the redline gear oils.