Rear, Front Diff's and Transfer Case Oil

Hi, new to the forum. Amateur DIY mechanic. I'm doing my diff's and transfer oils. I bought

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 with a friction mod mixed in already (Valvoline 75w-90 high performance gear oil). Will the modifier hurt my transfer case?

On a side question, is a friction modifier needed? I have contacted my dealer and they told me they DO add it to their services. Toyota has told me that it is not recommended in the manual so they wont recommend it. I do get a lot of conflicting information on this topic, anywhere I read. I would appreciate a clear cut yes or no and reason (if this is at all possible).

Thanks everyone.

 

Only 2005-2008 TRD Sports need the modifier, however the modifier will not hurt your diffs or tcase. I just used the same oils in my 2014.

 

Yup. Used the same excat oil for my 60k service (now at 70k) and nothing has exploded yet

Friction modifiers are for mechanical limited slip diffs. But works fine in 'normal' applications as well

 

Thank you. What is the reasoning I don't need the modifier? I do have a LSD, I have a hard time understating this as well.

 

It was my understanding that early year Sports had LSDs. Other models / years either had a standard open differential, or the e-locker. I have seen a bunch of conflicting info on this topic though.

Either way, you should be covered.

 

Yours is not mechanical, it uses the abs system instead.

 

After reading a few posts, I felt like I became more confused as to which brand of gear oil I should or should not use so I stopped reading. I looked at the owners manual and went to the local auto parts stores and settled with these. I have not heard any explosions from underneath yet either.

 

I changed mine yesterday. Owners manual called for 7qt. total for both diffs, transmission and transfer case. It actually took 8 1/2 qt. I used Valvoline HP buy one get second 1/2 price. Cheap ass pump took over 200 pumps.

 

Those are fine. If your Sport is 2009 or newer, you don’t need the additive.

 

I only use the pump on the front diff. On the rear and tcase I attach a short clear tube and squeeze the oil in. There is plenty of room especially if you drop the spare tire.

 

I used to do that till I wore a quart.

 

I used Mobile 1 in them 75-90.
Yes starting in 2009 no real LSD or posi unit in Tacomas. When a rear wheel starts to slip the ABS fires and the engine management can ramp your throttle down too. Only the TRD Off-road models can truly lock the rears together in 4Lo (the e-locker). Other models, even TRD sports, do not have this capability. NO Tacoma has any true LSD/posi anymore you have go aftermarket. They cheaped out as most buyers have no clue what real limited slip diff was and with traction control they can tie it all together in the ECU to handle (somewhat).
Ever see a 2009 and up Tacoma (without e-locker) try and pull a stomp or big load out when slippery you hear the ABS firing and the engine ramp down! On the Off-road with the e-locker engaged in 4Lo it actually shuts off the ABS, engine management and ATACS (traction control) as all the dash lights come on.