Front & Rear Differential Factory Fill Low

The issue is that when you do a dry fill, it’s full, but after some use, oil will slosh around and coat things. Now when you drain it, some oil will stay in the various places like the axle tubes, coating the gears, housing and other components above the fill plug, etc.

Now when you fill it again, there will be more oil in it than when it left the factory. Does that mean it was low when it left the factory? I suppose it depends on your definition.

I’m sure by Toyota’s definition, it isn’t. But I’m also sure by Tacomaworld’s definition, it is.

Jeff

 

lmmfao...same issue is "reported" on every auto forum...Factory under fills (insert your choice) fluid to save money...Only fluid that's not to spec is gas...

 

My 2016's diff's were spot-on when I brought it home. The auto trans... now that's a different thread altogether.

 

I just did the 30k front rear and transfer case. All levels seemed fine, the front diff fluid was noticeably dirtier than the rear. Transfer case looked perfect and I could have probably left it alone for the 60k change.

Kinda makes me wonder what percentage of owners actually change the driveline fluids, my guess would be probably less than 5 percent

 

Some of the fluid perhaps, but I doubt half a quart is going to be sticking to the housing/gears, especially after the truck has sat awhile and then you drain it.

More likely, IMO, is that Toyota is filling the diffs only to a minimum acceptable level, enough to preserve integrity/longevity of the diff while also saving money. (0.5 qts of gear oil * $15/qt = $7.5 per Tacoma * 200,000 tacomas per year = $1,500,000 saved every year just on rear diff gear oil for one vehicle type!

At the end of the day, I'm not worried. Now if diffs were burning up in large numbers due to them filling them below an acceptable level, then I'd have a big problem with it... but that's not happening.

 

You only get larger rear diff with an MT. All autos share 8" diffs. Could be sport, pro or OR.

Edit: i was wrong, thanks to TW police

 

2014 Tacoma 4wd rear factory fill low, this is not a new phenomenon, just fill it with the factory specs and get on with life

 

AT ORs and Pros get the 8.75in rear diff also.

 

great point, by Tacomaworlds definition everything is a catastrophic issue based on what their personal feelings are on trivial non problems

 

Do you seriously think that Toyota is paying $7.50/qt for gear lube? Here's $3.40/qt without even trying:


That's just enough to fill about 36 Tacos. They use over 6,500 times that per year, just on Tacos. Guaranteed they are paying less than $2/qt, which cuts at the penny pinching conspiracy theory.

 

Ok fair point, I was totally guessing on price they pay, lol. Still though, not worried about any of this.

 

Oh, thought its only MTs. Thanks for clarifying.

 

Same here.

 

No problem!

 

So does that mean AT pros and ORs come with 4.3 rear end instead of 3.9?

 

No. All V6 ATs have the 3.909 gears. 4.30s would probably have made a lot of folks happy considering the MPGs that we see even being geared a bit lower overall.

 

I think you underestimate how much stays in the axle tubes.

Jeff

 

That's really not enough to worry about. Your diff isn't going to fail because it's half a quart low. Nobody builds/designs stuff that way.

How do you measure driving smoother? You don't because you will feel differently about it any day of the week. Same goes for that noise. It might be a little quieter now, but it won't stay that way.

 

I believe the factory fill for the front diff is a different lube than the rear diff, is a darker-colored lube right off the bat compared to the rear diff, T-case.

What amazes me after all these years Toyota still trots out the same ridiculous 10mm Allen drain/fill plugs for the front diff. They were shitty in 1964 and Toyota still trots them out 50 years later.

Tundra, 4Runner, Taco, they all have those same ridiculous 10mm Allens on the front diff.