Differential fill and drain bolt size

[JayRolla]

My saga (short version)

The rear diff was rusted to hell and it took about 24 hours of PB blasting, hammering, straining until I finally tried the "car-jack-on-the-ratchet" trick and it worked. The oil was black and goopy but it was full.

The transfer case nuts came off easily and the fluid was in good shape, but still changed it.

The front diff fill bolt came off easily but the drain bolt got half-stripped when I used my foot to push on the ratchet. I put my finger in the fill hole and couldn't feel liquid anywhere! So Ill let it soak in PB Blaster some more.

I'm doing all diff fluids today. Not much rust here so I'm hoping the bolts come off. Wish me luck.

 

[Twan]

Tried to do my front diff yesterday. Both of them are seized and the fill plug started to round off. Going to have to let someone better equipped than I get those suckers out.

Also pissed off that the diff carrier bushings can't be replaced separately, since one of those is toast too. $100 for the entire arm with bushing.

 

[brisamh]

when you say "Rear Diff 75(80)w-90"

Why 75 or 80? Which is recommended / why?

 

[BrianK14]

I love PB but my oldest son got a 97 Ranger that was from Ohio back in 2013. we discovered some stuff called Kroil. (aero kroil for the aerosol version) Only available from industrial suppliers. about 13 bucks a can. worth every penny when needed.

then About a year ago saw an article comparing penetrating oils that put it at the top of the list for commercially available products. But it also used a 50/50 mix of brake fluid and lacquer thinner did better than anything at freeing frozen bolts. I havent personally tried that one.

Brake fluid and lacquer thinner? Haven't heard of that one. I use a mix of ATF and acetone. Works great.

 

[SilvFx]

when you say "Rear Diff 75(80)w-90"

Why 75 or 80? Which is recommended / why?

It has been my experience that the conventional dino based oil only comes in 80W-90. Synthetic gear oil comes in 75W-90 and 75W-140. Have used Mobil 1 75W-90 full synthetic gear oil in '99 4Runner for years without issue (front diff, rear diff, transfer case).

 

[4Runner4Leon]

Great thread, I am adding some photos below to show the locations of the drain and fill plugs.

I used my 18V cordless Makita Impact to loosen all the plugs, except the front where I had to use hand tools.

The front diff plugs on my '97 were 10mm (fill) and 12mm (drain) internal hex. All other plugs were 24mm.

Also, the transfer case drain plug was not magnetized.

Here is the rear diff:



Transfer case:



Front diff fill:



Front diff drain:



I used Mobil1 75W-90 for all three, and a kit of crush washers from Amazon:

 

[kolelt]

Valvoline 80w-90 in everything except my manual transmission. Don’t loose sleep over 75w or 80w. I get 80w-90 valvoline because it comes in a gallon.

 

[4Runner4Leon]

Valvoline 80w-90 in everything except my manual transmission. Don’t loose sleep over 75w or 80w. I get 80w-90 valvoline because it comes in a gallon.

I'm sure that's fine too. I just went by this:

 

[kolelt]

I'm sure that's fine too. I just went by this:

I understand. Just saying that you can save a lot by getting valvoline 80w-90 gallon. To each is own. But 80w or 75w. It’s not much different. I change my fluids ALOT because I off road a lot and play in water and mud.

 

[4Runner4Leon]

I understand. Just saying that you can save a lot by getting valvoline 80w-90 gallon. To each is own. But 80w or 75w. It’s not much different. I change my fluids ALOT because I off road a lot and play in water and mud.

Got it, and I appreciate the tip! In my case I got the Mobil 1 for < $9/qt, so $36 a gal. The Valvoline gallon seems to be selling for about $23/gal, so maybe ~ $15 total savings for all three boxes. I can see that it would add up for frequent changes, but I expect to change mine no more than once a year. But good to know, thanks for the info!

 

[AZZTR0CREEP]

i hope all the good things in life happen to you, ty for the rear diff plug gasket #

Do NOT use an impact on drain plugs, it's a good way to strip out the threads in the drain pan, diff, case etc.

DO use a six sided short socket on a breaker bar (I used a 16" 1/2" drive) rather than a deep well or an twelve point. The closer you are to the plug the less likely you are to slip and round it out.

DEFINITELY change the crush washers and use the appropriate washer for each application.

ALWAYS remove the fill plug first so if the drain plug rounds off or won't budge you can drive to a shop to have a nut tacked onto the plug and removed.

It's RECOMMEND that you use a torque wrench for installation of the drain plugs.


Transmission 75w-90 GL4 only 2.3qt
Drain
Crush washer 90430-A0003
24mm hex magnetic plug 27ft-lbs
Fill
Crush washer 90430-A0003
24mm hex plug 27ft-lbs

Front diff 75w 90 GL5 1.2qt
Drain
Crush Washer 90430-24003
10mm magnetic allen head plug (2000) 48ft-lbs
Fill
Crush Washer 12157-10010
10mm allen head plug (2000) 29ft-lbs

Transfer case75w-90 GL5 1.1q
Drain
Crush Washer 90430-A0003
24mm hex plug magnetic 27ft-lbs
Fill
Crush Washer 90430-A0003
24mm hex plug 27ft-lbs


Rear Diff 75(80)w-90 gl5 2.6 or 3.1 with locker
Drain
Crush Washer 12157-10010
24mm Magnetic Hex 36ft-lbs
Fill
Crush Washer 12157-10010
24mm Hex 36ft-lbs

Oreilly and Autozone continually waste my time and money on wrong parts..... thank you

 

[MountainBrew]

I would like to replace front and rear diff drain and fill plugs with the lexus 14mm hex plugs (apparently much harder to round these off than the stock ones). Ive seen conflicting part numbers for these, some of which are difficult to procure. Has anyone done this and have confirmation on the correct part numbers for these? Transfer case would be a nice bonus too.

 

[3bears]

usually its only the front diff drain and fill that gets replaced , rest are standard type using a standard socket
well at least on my past 3 4runners

 

[cl4Rk]

I would like to replace front and rear diff drain and fill plugs with the lexus 14mm hex plugs (apparently much harder to round these off than the stock ones). Ive seen conflicting part numbers for these, some of which are difficult to procure. Has anyone done this and have confirmation on the correct part numbers for these? Transfer case would be a nice bonus too.

Front diff is the only one with the recessed hex style bolts.

These worked for my 2000 4x4:
- Front diff fill plug: Lexus PN 9034118060
- Front diff drain plug: Lexus PN 9034124016

 

[octanejunkie]

Got mine for $9.48

View attachment 393908

I don't see a need to change the fill at this time...

EDIT
90341-18060 comes up as a Toyota part and my local dealer has it for $7.26.... tempting

 

[3bears]

ordering my lexus style drain and fill b4 this summer diff oil change, I assume uses same gasket as stock ?

 

[PerfectTommy]

great thread with a lot of useful info.

thanks.