lets beat a dead horse

ive read so much on the topic of transfer case and diff oil i think ive confused myself more then not. ive got an owners manual for this truck and it says for the t case recommended oil is 75w90 1.2qt so thats just regular old 75w90 gear oil correct no additives or anything crazy? im assuming not or it would say it. and for the diff gear oil it says LT 75W-85 GL5 or equivlent. 4.9qt. i dont think i have limited slip. its got a traction control button i can turn off and to my understanding that means the diff is open and the traction control just applies brakes to which ever wheel is spinning. do i have that correct? trying to figure out if i need the additive for limited slip or not. thanks

 

For 2nd generation I always used synthetic

$39 75w-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w-90 in all cases for the past 13 years.

 

Does yours have limited slip diff? Will the limited slip diff additive have any negative effects on a non lsd?

 

2nd gen Tundras have open diffs

This

 

As stated we don't have a true lsd. I do have an aftermarket lsd, Speedmaster, that requires a 85w-140 conventional oil. But that's not what is stock.

 

Good enough for me, just ordered 2 gallons of triax 70w90. Do you guys use Toyota trans fluid or do you use an alternative?

 

Gotcha. I thought I had read somewhere that the 2nd gen’s could have come with the lsd.

 

Like these guys said ^^^… a quality synthetic 75w90 all the way around will work great. You can use 75w85 in the diffs if you would like - it is usually a little more expensive and harder to find but zero issues running 75w90.

To clarify a few things for you - 2007+ tundras were never offered with a mechanical limited slip differential from the factory. Like @Mdl, I’ve run an aftermarket LSD for quite some time - first an Auburn gear clutch type LSD, now a worm gear type Speedmaster. The stock AutoLSD system is simply traction control that will engage the rear brakes independently to limit wheel speed and send power to the wheel with traction. Many call it malarkey and useless, but it is very functional in the right circumstances when used correctly. The differential itself is an open differential, though. I obviously felt the need for more traction in all circumstances and upgraded.

A note about the transfer case: in 2014, the transfer case changed from an Aisin to a Borg Warner unit, and the required oil type was changed to a straight 75w. Dealerships and many owners still use 75w90 in it without issue, but be aware that anybody suggesting straight 75w is referring to 2014+ tundras; your 2012 still wants 75w90.

Regarding transmission fluid, I much prefer Toyota or Aisin WS ATF. I wouldn’t muck about with anything other than WS unless you have a justifiable need for different transmission behavior. Aisin is the transmission manufacturer, and Toyota owns Aisin. So in my book, both this ATF’s are well suited to our vehicles. General consensus - and my preference and practice - is to perform a drain and fill rather than a flush. I’ve done so every 30k miles since new on my ‘13 and am currently close to 230k miles with lots of hard use. You can do an drain and fill with every oil change (or sooner) if you are lookijg for cleaner fluid. There is a little procedure for it that you can look up here on the site. Simple, but a few things need to be followed closely. No more difficult than an oil change, IMO.

 

thanks for the clarification. I also plan on doing a drain and fill not a flush and at the 30k intervals. The truck has 50k on it now and I doubt it’s been done so I’d like to get it on a regular service schedule and keep everything as nice as I can