2015 diff and transfer case oil and spark plug questions.

2015 Tacoma dc sb manual.
Changing the front rear dif oil along with the transfer case oil.

is the Valvoline full synthetic 75w90 a good choice for all 3 or should I go with something else in the transfer case? 92k miles and changed at the stealership for free at 32k and 60k.

plugs, what’s the best option at Napa for the 4.0 as that’s the only place local or I can order from Amazon as well.

 

If you can find Denso iridium plug at nappa then get those. I would stay clear from Amazon since you can sometimes get counterfeit plugs. Get them at rockauto if you wanna buy on line.

 

Rockauto is where I bought my plugs from. But I just went in with the standard plugs that were in there originally.

 

Valvoline 75w90 is fine.

Plugs stick with the OEM Denso K20HR-U11 copper. RockAuto has them for like $2 each. Iridium’s give no extra benefit, don’t buy the snake oil. Don’t buy them from eBay or Amazon, too many counterfeits that can damage your engine.

 

Is that even possible to get counterfeit plugs. They come in the right packaging and the right markings on the plugs. In that case anything and everywhere you buy them can be counterfeit.

 

You’ll be fine with

$28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90
Don’t order Spark Plugs on the internet unless that’s your only option.
My local Napa carries the Bosh.
I prefer the Bosh over NGK when used in the 4.0 engine.

BTW, Both Bosh and NGK part # are in the owners manual. They are standard copper core. Nothing special about them.

Sure you can use Iridium. But the standard copper core have been known go along time.

 

Awesome thank you for all the info as usual. Time to head to Napa and get some work done!

 

Yes, and misinformation as has been provided here as well. You can safely order from Amazon if you avoid third party vendors. Each product web page shows who is selling the item; to avoid buying counterfeit items, order the item if it shows it is being sold and shipped from Amazon. Exceptions exist for trusted third party vendors; for example I order my pulley bearings from Rodavictoria, who also sell on eBay.

Iridium plugs are fine for our Tacos if you want to go that route. I'm on my second set. Their benefit is longevity, 50K to 100K. I changed my first set at 115K, but I would not go past 100K. If the Denso/NGK application guide shows an iridium plug# for your vehicle, you can safely and confidently use the product. Besides, Toyota is part owner of Denso; if Toyota did not want iridiums in our engines, they would not allow Denso to list them, or they would warn Taco owners not to use them. I have looked for and not found a TSB advising against their usage.

Re gear fluid, Valvoline full synthetic 75-90 is fine. I have it only in my rear diff. For the front diff and transfer case, I use the more affordable SuperTech synthetic blend. My limited slip requires an additive but I can leave it out if I use full syn.

 

I don’t order plugs online because I don’t like broken plugs. I like to take the plugs out of the box and inspect them before I leave the store. If you get a broken plug, you’ll usually find it about the time you put in the last plug of the job.

I’ve been there. I didn’t like being there.
I don’t want go there again.

 

I stick with copper plugs since that is what Toyota recommends for the 4.0. I like to think they know more than me.

 

Two counter points on this:
1. Car owner manuals are not updated with improved products and procedures. (One can argue TSB’s fill that role somewhat.)
And
2. Reputable aftermarket manufacturers are also smarter than you. They also have engineers who have developed quality products and present them to you via their application guides.

 

There is a TSB for copper plugs?..JK… The majority of people here run copper; sure there are a lot that don’t and they run great with less maintenance. I think it would be foolish to not let OP know what is “recommended” by Toyota.

 

Nope. He asked, “plugs, what’s the best option at Napa for the 4.0…”. Who thinks they can get oem plugs at Napa?
I will agree you can’t go wrong with oem, but that, clearly, is not what he asked.

 

I've actually gotten better mileage from the iridium plugs. The other benefit from iridium plugs is that you don't have to change them as often as the copper plugs. So if OP is the type of person who likes to set it and forget it for a while then iridium is the way to go.

 

I'd be willing to bet that the increase in MPG is "butt dyno" or there was something wrong with your old plugs (e.g. gapped incorrectly).

The sole purpose for iridium, platinum, etc. over copper is longevity. Copper is actually a better conductor than iridium and theoretically should deliver a "stronger" spark than iridium but in practice it's negligible.

 

For plugs NGK or Denso ONLY. Don't F around.

 

When I bought my truck I took it for a pre/purchase inspection.
The mechanics were very Tacoma knowledgeable.

They told me to make sure to use the normal OEM spark plugs and OEM coolant - not try and be fancy and put the iridiums in there; it was one of the specific things they told me past, "if you don't buy this, I will"

And since I didn't live in the area, they were only getting the 60$ out of me and really had no incent to lie about shit.

I will trust the guys who do this stuff day in/day out and have to deal with the blowback if it goes bad.. over a manufacturer's table of what fits/etc and may work.

 

As Chuy indicated above in post #11, sometimes improved items come along that can and/or should replace the original part.

When Toyota went to dual VVT-i on the 1GR-FE they switched to Iridium plugs for superior ignition performance with increased durability.

1GR-FE 4.0 V6 - Everything You Wanted to Know | Tacoma World
Ignition
The 1GR-FE had long-reach spark plugs that were positioned in the centre of the combustion chamber. For the VVT-i 1GR-FE engine, the spark plugs were either Denso K20HR-U11 (nickel type) orNGKLFR6C-11 (nickel type). For the dual VVT-i 1GR-FE, the nickel type spark plugs were replaced by

$59 Denso SK20HR11 ---- IRIDIUM PLATINUM power pack Spark Plugs -- # 3421 ----- 6 PCS NEW

Denso SK20HR11 iridium-tipped spark plugs which had 200,000 km maintenance intervals. By adopting an iridium centre electrode, ignition performance was superior to that of platinum-tipped spark plugs and durability was increased.