98 V6 rear end fluid change

Hello,

I am planning on changing out the fluid in the rear end on my pickup soon. I don’t know how long it’s been since it’s been done is the reason for doing it. It now has 279,000 on the clock. I also am not sure if it’s currently synthetic or not but if not it would likely be a good time to switch to it or no? If so what weight would I be looking for? I know the weights are all over the place vs the oil designations. Thanks

 

I went with Redline

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

75W-90. Should be good for a long time.

If I were offroading a bunch and expected that it might get messed up, I'd go with something cheaper, like Supertech from Walmart.

 

Good plan. Does it take 2 quarts or less? I can’t remember

 

Probably between 2 and 3 quarts.

All the capacities are in the owners manual, which you can get for free here:
https://www.toyota.com/owners/resources/warranty-owners-manuals

 

You should be doing all the fluids,
Tcase, Trans, front and rear diffs and check the breather valves

 

I am planning to. I’ve actually already done all but the front and rear diff and breather valves

 

The Amsoil bags make it soo easy and you can reuse those bags , no pumps needed,
Don’t over fill the front diff tho, it will push out the breather valve if you put to much in.
Be careful and don’t strip out the lower Allen drain bolt too,
You can get an Lexus bolt head replacement instead of the Allen type

 

With the transmission and engine, I use synthetic, but in the diffs and transfer case, I stick with dino juice. Those seem perfectly happy with the cheaper fluid, and I've never had an issue - though, I try to change the rear every ~30K miles, and the front+transfer case every 60K.

Rear Differential Oil Change - covers the fluid amounts and parts you need for the rear.

Sounds like you haven't done the front yet either - so here's what I do for the front, again with fluid amounts - Front Diff Oil Change. I have to say, I do like John @1997tacomav6's point about the Amsoil bags and not needing a pump. That's a pretty cool idea.

Here's the info on the Lexus drain/fill plug replacements for the front diff. These things are pretty great:

A Front Diff Drain (and Fill) Plug that Doesn’t Suck

 

I've seen other (cheaper) brands come in a bag now (valvoline synthetic, IIRC). When I tried to drain the front diff, the drain plug was seized, so I just used an extractor through the fill hole. One of these days I'll bust it loose and replace with the lexus plug.

 

As for the breather valves are they serviceable by way of cleaning or just check and if they don’t let air move they need replaced?

 

I soaked mine in WD40, then tooted them with compressed air (wear safety glasses). If this method doesn't free them up to your liking, then they are cheap to replace.

 

Sorry, I noticed that as well and meant to include this link. Relocating the rear diff breather is easy, cheap, good practice. It's location there on top of the diff is quite terrible for a breather. Leaving it there can cause it to clog, and then you risk having to replace your rear axle seals (and bearings) which is a much less fun job.

Here's how to do it on a Tacoma: Rear Diff Breather Mod – Why didn’t I do this sooner?

You can see what happened on my 4Runner when I didn't do it: I’m Too Late! – Rear Diff Breather Mod on 3rd Gen 4Runner. Ended up having to replace the seals and bearings. A good learning experience.