Differential Fluid 1/2 Quart Low

Hey, Was under 4runner that I purchased a few months ago just looking things over.. ,Told my wife I’m doing some light maintenance and she rolled her eyes cause she knew what that meant, jack, stands, removed skid plates etc lol. I removed the rear skid plate for the first time and I noticed oil leaking from what appeared to be coming from the front differential drain cap. I went and purchased Mobil1 synthetic LS just to top it off to see how low it was. I ended up pumping in a little less than a half quart (12 ounces).. it appears to be a very slow leak so who knows how long it has been low since I bought this used (it’s a 2016). Do you think this caused any damage? I am going to order the crush washer and some Redline and drain and refill soon but just wondered if I should be concerned... Thanks!

 

I assume you're referring to the rear diff. I have a 2019 Offroad, so it's probably the same as your Trail. When I drained and filled the rear diff fluid, I pumped in the amount (2.65 L) specified in the owner's manual. It didn't reach the bottom of the fill hole, so I kept pumping. I can't remember how much more fluid it took to start dripping out of the fill hole but I think it was over 1/4 of a quart. I'll have to look for my notes. I drove around for a few days and OCD took over so I ended up pumping out the excess.

I may have read your post wrong. If it's your front diff, the recommended fill is 1.55 L, so if it was a half quart low, that was pretty low! It may still be fine but I would keep an eye on it.

 

Yeah it was the front differential.. is the front differential only engaged and turning when it's in 4wheel drive? Maybe it's turning but since most of the time it's not in 4wheel I was thinking maybe it wouldn't of really been under a load and therefore low fluid wouldn't of really caused much damage?

 

There’s no reason your differential should be leaking unless they didn’t put the drain plug back on right.

I’d buy a new plug and washer and install it after you top it off.

 

If it's the pinion seal, it should be wet around it. Axles seals would be around....the diffy output shafts

 

It's only wet around the drain plug... Dry everywhere else....

 

Lucky you then, easiest fix!

 

Probably some dripping from filling the engine oil.

 

Put a new crush washer in

 

You pumped out the 1/4 quart even though it was not overflowing from the fill port? Doesnt the fill port define the correct level?

 

Had to check my notes. The recommended fill on mine is 2.65L (2.8 quarts). Each model has a different spec, so be sure to check the owner's manual for your model.

Anyway I initially pumped-in the recommended 2.8 quarts and was expecting it to start dripping out the fill hole. It didn't, so I kept pumping until it did, which took a total of 3.2 quarts. Went back a few days later and pumped out the excess 0.4 quarts.

Honestly it probably wouldn't have mattered, but lesson learned. I'm sure a lot of people keep pumping until it drips, and I doubt it causes problems.