Rear diff oil level issue!

So on a whim, I decided to check the oil level in my rear diff. Correct me if I’m wrong but to check it, I open fill plug and put my finger in diff and if I feel oil, I’m good to go?

I didn’t have any oil on my finger! So I ended up putting just over a quart of

$26 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 in my diff!! WTF?
I’ve been driving Tacoma since day one with low diff oil? 21k miles so far!

What should I do next? Contact dealership and ask they’re opinion? It’s still under factory warranty.

Haven’t noticed any adverse effects yet though.

 

Correct, with the truck parked on level ground, the oil should be level with the fill plug. You fill it until it starts trickling out.

I would do a full drain and refill. If there is no noise and no chunks of metal on the drain plug, I would call it a day. If you want to take it one step further, you could take it to Toyota for them to document it for if any problems arise in the future. I'm not sure how willing they would be to do that though, since you already filled it up and they would essentially be taking your word on the fact it was underfilled.

 

Good idea, thanks.
I also made appointment at dealership to check rear AND front diffs for oil levels and any damage. And also to document this potential situation.

 

Personally I would check all the levels . If it's low let the dealership tell you . See if they are honest.

 

The 'proper' level is just below the fill plug. I think they spec 5-10mm below. But if you just fill to when the oil comes out the fill, you will be OK. Make sure you are on level ground. Also, if you change the oil, go back and recheck after a drive because sometimes air pockets when filling will cause the oil level to settle lower after driving. Always a good idea to recheck.

 

When you say check the front and rear oil level. Do you mean, all they are going to do is open the full plug and see if it is full?

If so, seems to me like a wasted trip.
You’ve already done half the work for them. Might as well do the front and know for a fact it is full.

 

low fluid from the factory might explain why some people get a diff whine and other don't. glad i changed mine at 500 miles. seemed a bit low and had a bunch of metal shavings on the magnet.

 

I'd be surprised if it's different for third gens, but spec for a second gen is 0mm-5mm. I don't have access to that FSM otherwise I'd check.

 

https://www.ttguide.net/differential-1280.html

 

Tis the same indeed. Thanks for the resource.

 

Thanks for all the quality replies. I will definitely check my front diff as well. So far so good with the dealership where I bought truck. They warranty replaced both my rotors without any fuss.

I am including the dealership in this situation in order to document everything since truck is still under factory warranty. When I take it in, they will drain-flush-refill diff and inspect. We’ll see what they do if front is low. I’ll know it’s oil level before I take it in.

 

No problem.

I say it’s full when it starts coming back out the fill plug.
But that is my preference and not “technically right”.

 

I had problems with the whining noise coming from the rear diff at 30k miles, send it to dealer, they couldn't find anything wrong.

I decided to change the fluid. I measured 3.2qt came out of the diff., manual calls for 4qt. No visible leak of any kind.

 

Learn to do this simple probing yourself
I do not trust dealerships.
But then im a lifelong mechanic

 

Well that’s what prompted this post….simple probing. But you’d be a fool not to involve the dealership with a warranty issue. Free is far better than $$$.

 

I did a drain & fill at 3,000 miles.
3 1/2 qts came out of my rear diff, and it took 4 1/4 qts to fill it.
From the Factory, 3/4 qt low is not good - glad I decided to do it!

 

That’s understandable.

But I don’t think the dealership is going to drain the differential and inspect it for damage if it’s low.
My bet is, they will top it off and send you on your way.

That’s what I’d do if it were my truck. Top it off and drive it.

 

It’s not low after I topped it off today (about 1.3 qts added). I wonder since it came from factory low in rear diff if front diff is also low. I will check that next.

Dealership stated in writing that they will drain, flush, inspect and refill both diffs. Again, I simply want all this documented with dealership for any potential issues ahead.

Also, drive train is a 60k mile warranty.

 

You don't mention any evidence of a leak so that leads to a question.
Who did the 10K & 20K oil changes?
Doesn't checking all the fluid levels fall under the multi-point inspection?
(or the pre-delivery, dealer prep inspection)

 

No leaks. Dealership did the 10 & 20k oil changes via Toyota Care. Diff oil changes and level checks were not part of the free services. They claim to perform a 29 point inspection each time, guess the diffs are not one of the 29 points.