Rear Diff-How Many Quarts?

Drained and refilled Rear Diff today. Took 4.3 Quarts to refill. Going by the info on this maintenance guide, it should've only taken 3 Quarts. My Tacoma is a 2nd Gen, 4.0L, 4X4 just as listed on the guide.
https://www.tacomaworld.com/threads/2nd-gen-diy-maintenance-quick-reference-guide.438945/

The rear was jacked up a foot, but I can't see that causing over 1 Qt difference. Is the guide wrong? Should I open the fill plug while level and let the excess drain? Is overfilling a problem?
Any ideas?

 

You needed to fill it while the truck was level on the ground. Fluid will come out of the fill port once the proper level has been achieved.

 

I do mine with 3 quarts not using every drop of it on as close to level ground I can find. With the truck on the floor no jack.

would be cool if there was a way to know its level.

Etsy has a bubble level but it’s for old land cruisers I think. Could be useful offroad and camping.

I think Hilux or Surf has a factory one in ROW, inclinometer unit on the dash. That folks fit on older US Toyotas because it matches the interior design and there’s a spot for it.

for this task likely easier to find a parking lot than to be putting a level on axle and frame, which itself depending on suspension the frame may have rake.

without putting too many miles you can always do a fill level check somewhere else let the excess come out.

 

I uses 2x4 blocks of wood to level the truck when I do diff fill-ups and ATF refills. I have a sloping driveway, so I need four blocks under each rear wheel, and use single blocks to build a mini ramp.

 

yeah maybe on the frame. Just gonna keep finding flat ground. Suspension has forward rake so it’s probably not gonna measure level even on flat ground.

 

Another use for this, if you really want to get technical lol because it’s self leveling, you could measure points to the line..

 

Just had a similar result when I did my front diff last week. Specs say 1.5 for front but I added almost 2 before anything started to weep back out.

 

Thanks to everyone for the help!
My driveway is pretty level but, I cannot get under and work under my truck. Maybe with the 3" lift-kit I want?

I leveled and drained the excess.

I realized after the replies, I could jack up the rear at the trailer hitch; lifting the chassis without lifting the tires and diff. That allowed me to get under with my creeper. Still not much room for my arms but enough.

So that's one lesson learned.

I also learned you can't squeeze all the oil out of those bags. So 4 quarts is really like 3.6 quarts. You can consolidate all the un-squeezed oil into one bag.

Somebody tell me if it is advisable to jack the rear at the differential? That would allow me to use ramps at front and jack the rear level. So I can do the Front Diff, Crankcase and Transmission.

 

I see you have a 4x4 so you should have quite a bit of room under the truck to service the rear diff with all 4 wheels on the ground.

But if you need an extra inch or two, put some planks of wood in front of each wheel and drive up on them. This will evenly raise the truck so you can move around underneath easier.

 

I'll be looking for some 4"x4" wood blocks.

My 4X4 is not a TRD. I think my truck's height is the same as an SR5 PreRunner. I myself am an XXL, I have a friend who does his without Ramps or jacks. He's 5'7" and skinny.
Even after lifting the chassis at least 6 inches at the trailer hitch, (stopping b4 the tires left the ground) Sliding in on the creeper, I had to raise my arms over my head b4 sliding in... so-as to have them available to work on the diff. I'd say only 3.5 inches from my chest to the spare tire and exhaust. But this worked. If I get the 3" lift done, I'll have shocks and springs checked. Maybe she sits a little low?
With the front up on 8 inch ramps, there's a little more room to do the crankcase, front diff and trans. But, I then must lift the back to be level.

Also, covid almost killed me, after a loooong time in hospital I had to literally learn to stand and walk in rehab. 7 months total till I got off oxygen and I still could barely/painfully walk. 1.5 years latter I still have trouble getting down and up. Just now starting to have that ability. I'm so thankful I can do these things at all. So a creeper is necessary. That takes up at least 2.5 inches.

Still trying to learn if using the differential as a jacking-point is taboo?
I could just by another set of ramp[s and drive up all four. That would solve a lot.

 

As long as the truck is “close” to level you are fine.
Fill it until it starts to run out the over flow. You’ll technically be “over full” doing it that way.
But close enough is “good enough”. You’d have to be on a pretty steep incline for it to make any difference. FWIW, bringing the front of the truck UP will make the diff hold less.

Seriously though, no need to make it complicated.
I’d be worry more about side to side, then front to back.
Side to side will let the fluid run down the axle tube and be “way” over full.
Front/back…….not worried about it.

 

I think you are correct on all counts. However, No exaggeration... putting the rear up on 8" ramps resulted in about a 1 quart overfill.
I corrected it by jacking only the chassis at the hitch while leaving the tires on the ground (so I could get under there). Removing the fill plug and letting the excess drain to a trickle.

Thanks for the help!
Can you answer whether or not the diff can be used as a jack-point?