Yeah, that topic sounds disgusting. Sorry.

I need to add some fluid to the rear diff on a '98 4-runner 4x4. I can see the drain plug (its the one on the bottom) but how do I get the new fluid into the diff?

I can see another plug that seems to be about halfway up the diff on the license plate side. Is that where I put the new fluid?

How much will this thing need?

Should I stick with the Toyota recommended fluid or should I use something else?

 

That's the fill plug. Fill until it comes out of the hole. Any Hypoid gear oil should be fine.

 

yes the drain is the lower of the two bolts on the diff. to put new fluid in i got a hand pump from auto zone or pep boys...worked like a champ! oh and 2.6 quarts.

 

Cool. How big are those plugs anyway? I dont think I have a socket that will fit.

 

the plug is 24mm

 

Definely use the right socket and hold it firmly on the plug when turning. Lots of guys round off that plug when trying to loosen it and are stuck trying to fill the diff through the vent hole. :cry:

 

I'll definitely be careful. I'd hate to have to feed my diff thru a straw!

 

I’m glad someone else posted something like this. I too have a diff problem. Mine seems to be leaking, a lot! At this time I am replacing my engine so I can’t afford to fix it so I was wondering if I could put some synthetic grease in there for the time being. I would only have to do this for about a month. Otherwise, I’d have to refill the diff every other day.

Is this a possible temporary solution?

Also, what would cause a humming noise in the rear diff. It starts at about 30 mph.
When I let off the gas it stops…Anything helps thanks.

 

Your axle seal is leaking.

I'm experiencing the same problem with mine at the moment.

There is a thread that goes over this; let me try to find it.

 

https://www.yotatech.com/forums/show...eaky+axle+seal

That's the link.

 

It's leaking from this area, not by my tires. The rear end of my runner gets covered in oil by this leak as well.
it's in this area...

 

You can try to powerwash it off, then use some brake cleaner and RTV silicone the outside of the case where it is leaking until you can get it fixed premanently.

 

Good pic. That looks like a supra TT auto/NA diff. Is it not?

John

 

with regards to the leak, the above information says it all. with regards to changing out the fluids, see here: http://www.4runners.org/articles/difftsf Also found in the "Tech" section.

bob

 

I'm not sure what car it's off, I was just using that image as an example.

 

Designsbyme,

my truck leaks right around there too, although to fix it, it looks like I'd have to take the driveshaft off
it really isn't too hard to fill though so that's the good part, I use a 15/16th inch wrinch and socket to loosen the bolts on the rear diff, transmission, transfer case and front diff. it comes out to be something like 23.7 mm so it should fit a lot better then a 24mm would, don't have to worry about striping anything.

as for synthetic.. wouldn't that just leak faster?

RTV Silicone? guess walmart doesn't carry that eh?

 

The diff posted looks like a regular pre-Taco IFS front diff.

If you are leaking bad enough to need to refill every other day, I think I would take care of that quickly. Synthetic ought to leak faster as was said.

In either case, it looks like you need to pull the third from the housing to get a new gasket or a bead of silicone.