Differential Fluid

[Mano1124]

So, my mom called me telling me that her 99 4runner was shifting hard when switching from park to reverse and drive. I checked the differential and has a major leak. To top it off, The filler plug is completly stripped. Tomorrow i'm heading to the stealership and pick up the filler plug and two crush washers. Now, what gear oil should i use? I'm going to get conventional but don't know what weight to get. Should i get 75-90 or go thicker? 4runner has 189k miles

 

[Singtoe]

My suggestion for your high milage diff is Lucas 85w-140 gear oil. It is the best stuff out there.

 

[K.C.]

Synthetic Fluid Changeover
Synthetic Fluids Toyota 4Runner Information

via J.A.

 

[Singtoe]

If you want to keep your diffs alive, don't run synthetic...

 

[02SE]

If you want to keep your diffs alive, don't run synthetic...

What's your rationale for that?

I've run Synthetic (Mobil 1 or Redline) in every diff I've owned or worked on for twenty years. No excess wear issues, or leaks with any of them.

 

[Mano1124]

Sorry guys. Just had time to check the thread. My mom told me she's looking into a 02 4runner right now. So i'm thinking of going conventional. Just wondering what weight. I too have a 99 4runner. Same color same model but with 155k miles. Im thinking of switching my trans, diff, and motor to synthetic. Just want to do a quick fix on my moms. The leak is actually on the filler plug.

 

[Nunyabiz]

What's your rationale for that?

I've run Synthetic (Mobil 1 or Redline) in every diff I've owned or worked on for twenty years. No excess wear issues, or leaks with any of them.

There is no rationale for that, synthetic is far superior in every way.
If anything you would have less leaks and certainly less wear.

 

[Nunyabiz]

Sorry guys. Just had time to check the thread. My mom told me she's looking into a 02 4runner right now. So i'm thinking of going conventional. Just wondering what weight. I too have a 99 4runner. Same color same model but with 155k miles. Im thinking of switching my trans, diff, and motor to synthetic. Just want to do a quick fix on my moms. The leak is actually on the filler plug.

For what you are doing Singtoe is correct the 85W 140 would work very well for that purpose.
But definitely change the fluids on yours to full synthetic though.

 

[Mano1124]

Alright, cool guys. So when it's time to drain and fill my differential, with no leaks, what weight of synthetic should i use and how many quarts does it take?

 

[quicksilvr]

So, my mom called me telling me that her 99 4runner was shifting hard when switching from park to reverse and drive. I checked the differential and has a major leak. To top it off, The filler plug is completly stripped. Tomorrow i'm heading to the stealership and pick up the filler plug and two crush washers. Now, what gear oil should i use? I'm going to get conventional but don't know what weight to get. Should i get 75-90 or go thicker? 4runner has 189k miles

I'm curious why nobody has mentioned that your issue of hard shifting has nothing to do with the differential?? You need to check the transmission fluid and change THAT.

 

[trailmix]

Also grease the zerk fittings on the driveshaft, sometimes those joints get sloppy with no grease in them and can cause it to shift hard from park to drive and reverse.

 

[TN_Soljah808]

Synthetic Fluid Changeover
Synthetic Fluids Toyota 4Runner Information

via J.A.

Alright, cool guys. So when it's time to drain and fill my differential, with no leaks, what weight of synthetic should i use and how many quarts does it take?

That post has all the information you need for amount required and torque. I run Mobil1 in my vehicle. However, I have seen a few post about Redline. But, it's not available locally so I didn't purchase it. Maybe I will later.

 

[Mano1124]

Cool. I'm off to the dealership. I'll check the tranny fluid too. Hopefully nothing expensive repairs are not in my future. Wish me luck!

 

[Tomsriv]

Unless you have a posi rear end I wouldn't waste the money on synthetic gear oil. If its that big a concern to you just change it more often. Chances are the fluid in your moms car has never been changed. Diff fluid is the most commonly ignored fluid. But rear ends are the longest lasting component of the drive train because they always have plenty of lubrication. I run conventional 85w-140, but its not that big a deal. Even my 38 Cadillac has an original rear end with conventional oil.

On my runner I changed it when I bought it at 113,000 miles. I now have 225,000 and haven't changed it yet.

 

[Mano1124]

Thank Tomsriv.

 

[02SE]

There is no rationale for that, synthetic is far superior in every way.
If anything you would have less leaks and certainly less wear.

Exactly my point.

 

[durrell]

He has pretty good rationale after talking to the guys at East Coast Gear Supply. I will let him explain, but it certainly all makes sense.

 

[Mano1124]

So I finished working on the rear diff. It was a PIA to remove the stripped fill plug. To top it off, I removed the drain plug with my hand. It was loose. I drained only 2 quarts!!! I filled with 3 quarts and replaced the crush washers. I used 85w-140 lucas. I checked the tranny fluid and it was full. Just dont understand why the gears shifts hard from drive to reverse. Im thinking of self flush the tranny.

 

[kball]

The rear diff is only supposed to take about 2.5 qtz I believe. Were you on level ground when you serviced it?

What do you mean by shifts hard? Do you hear clunking? Do what trailmix said and grease the drive shaft.

 

[Mano1124]

kball- I was on ground level when i filled it. It took close to 3 quarts before it started spilling. when i have the brake pressed, i shift from park to reverse and i feel a rough jerk and clunk also when i switch to drive.