Changing Rear Diff Fluid. Synth or Regular?

[swampy_swimmer]

HOW ABOUT THIS ONE?

DID ANYONE TRY IT?

 

[nobb]

That's interesting you say your gear oil looks almost new after 50,000 km (30,000 miles) and [MENTION=141906]PWD4R[/MENTION] says his looks perfect even after 50,000 miles.

Yep, and this is with a pretty simple but decent quality full synthetic 75W90 made by "Boss Lubricants" which is a local company. I got it for 1/3 the price (with corporate discount) of what a typical brand name product would be. That's why I sometimes doubt if those specialty "boutique" synthetic brands are really necessary for something as simple as a transfer case or differential.

I do run a premium Redline MT-90 transmission fluid though.

The whole k or km is a little confusing on this thread. When I hear somebody say 40k, I think 40,000 miles. But then others are saying km, which is obviously kilometers. Anyway, I think I got it figured out.

Haha now you know how I feel when everyone references everything in miles. Doesn't make sense to me!

 

[TorqueOfTheDevil]

There are no wearable materials inside an axle tube.

Errrrr, what?

I'd consider the crown wheel, pinion and bearings wearable items, they even have a run in period!

My only thought was that you meant the tube part itself, but that shares oil with the above mentioned, so regarding oil colour is irrelevant!

Eaton Recommend Mineral oil for use with Truetrac diffs... Toyota recommend Semi synth from memory. I can't remember what the Yukon recommendation was.

 

[Konkordmusk]

Errrrr, what?

I'd consider the crown wheel, pinion and bearings wearable items, they even have a run in period!

My only thought was that you meant the tube part itself, but that shares oil with the above mentioned, so regarding oil colour is irrelevant!

Eaton Recommend Mineral oil for use with Truetrac diffs... Toyota recommend Semi synth from memory. I can't remember what the Yukon recommendation was.

Certainly those items will wear...in the same way that seats wear, or steering wheel would wear; not necessarily an item designed to wear. The r+p certainly aren't items that one would change at regular intervals like brake pads. That is what I meant by wear item, apologies for lack of clarification.

 

[4runnerWiniarski23]

I definitely need to swap mine. I don't think it's been done in the 104k miles.... =(

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[RS Dude]

Well, something is happening with the gear oil to turn it a darker color and I'm having a hard time believing it can be attributed to dirt finding it's way into the breather. That breather hole is small and covered with that cap so I'm thinking very little dirt could find it's way into there, and if it did, it's not going to be enough to change the color of the gear oil. If it's true that much dirt can enter the diff breather, I'm definitely going to do the breather mod and run it up to the gas tank fill tube. I drive dirt roads quite a bit but I haven't had the need to cross any deep creeks so I haven't bothered with that mod yet.

I agree there's nothing really wearable in the axle tube other than maybe the axle seals and bearings, BUT, there's definitely wearable parts in the differential. The drain plug is magnetized and I find a small amount of metal debris attached to it every time I change the gear oil so there's definite wear happening.

In regards to the breather valve, I just bought a new oem breather and I tested it by blowing through it. A new or correctly functioning breater will only allow air to escape and will NOT allow air into the diff., which is good to know. I decided to replace mine at 295,000 miles because I recently replaced my rear bearings and seals and wanted to make sure everything stays perfect. Also, the breather costs less than $7!

 

[RS Dude]

i use this and i have had absolutely no leaks at 340k Kms

If an Amzoil cultist bumps into a Royal Purple cultist, what is the likely outcome:

1. A fistfight breaks out:boxing:
2. A knifefight breaks out:fencing:
3. A gunfight breaks out:uzi:

Just askin'? :guitar2:

 

[ThorInc]

If an Amzoil cultist bumps into a Royal Purple cultist, what is the likely outcome:

1. A fistfight breaks out:boxing:
2. A knifefight breaks out:fencing:
3. A gunfight breaks out:uzi:

Just askin'? :guitar2:

Purple Amsoil? [emoji12]

Sent from my SM-N900W8 using Tapatalk

 

[3rzrunner]

If an Amzoil cultist bumps into a Royal Purple cultist, what is the likely outcome:

1. A fistfight breaks out:boxing:
2. A knifefight breaks out:fencing:
3. A gunfight breaks out:uzi:

Just askin'? :guitar2:

pfff... royal purple.:uzi:

read this. -> https://www.amsoil.com/lit/g3115.pdf

 

[swampy_swimmer]

pfff... royal purple.:uzi:

read this. -> https://www.amsoil.com/lit/g3115.pdf

My latest engine oil change was rp 5w30 HM. Noticed slight fuel economy vs m1.

 

[vester]

i use this and i have had absolutely no leaks at 340k Kms

I second the Amsoil severe gear. Have used it for years and never had any issues.

 

[T4R2014]

People have used cheap-o bulk gear oil for years without issues... any name brand will do the job. Don't overthink this.

 

[swampy_swimmer]

Ordered amsoil 80-90 for rear and 75-90 for front and t-case. And their grease for shaft for good measure. And their break fluid... :hat: On the side note, I was able to check the records from prev owner's. It looks like dealer did full 90mi menu on her at 91K. All fluids were changed exactly 40K ago. So I'm right on schedule.

 

[thor999]

In regards to the breather valve, I just bought a new oem breather and I tested it by blowing through it. A new or correctly functioning breater will only allow air to escape and will NOT allow air into the diff., which is good to know. I decided to replace mine at 295,000 miles because I recently replaced my rear bearings and seals and wanted to make sure everything stays perfect. Also, the breather costs less than $7!

You got that P/N?

 

[TorqueOfTheDevil]

Certainly those items will wear...in the same way that seats wear, or steering wheel would wear; not necessarily an item designed to wear. The r+p certainly aren't items that one would change at regular intervals like brake pads. That is what I meant by wear item, apologies for lack of clarification.

Ahhh, ok, as in consumable items (Clutch/tyres/brakes).

Did the US 4Runner not have a friction plate LSD as an option? Or was that other markets only?

 

[RS Dude]

you got that p/n?

90930-03031

 

[RunnerFanTenn]

Wife and daughter's 4runners both over 250k, always on pavement....normal use. Have always changed differential at 75k (always looked good), and transmission at 100k (just drain and fill). Synthetic on both.

 

[RunnerFanTenn]

I use Mobil 1 75W90 for both front and rear diff as well as transfer case with good results, no leakage, 233K miles.

Use Mobil 1 also, change differential every 75k transmission every 100k. Pavement only, typical driving....very little towing. Both runners over 250k no issues.

 

[cdrewferd]

East Coast Gear, who does a crap ton of Toyota 3rds and other gears, recommends non synthetic Lucas Severe duty. They say to spend less and just change it more often. This is what I'm running in my diffs I got from them, and will always run as I agree with their line of thinking.

 

[repo]

East Coast Gear, who does a crap ton of Toyota 3rds and other gears, recommends non synthetic Lucas Severe duty. They say to spend less and just change it more often. This is what I'm running in my diffs I got from them, and will always run as I agree with their line of thinking.

I've seen their recommendation too and was going to switch to Lucas 85-140 conventional. But then I looked to see what the peanut gallery at bobistheoilguy was saying and they seem to think Lucas is pure junk. I'm just going to keep using valvoline/castrol/whatever 75w-90 conventional in everything and stop caring. The gallon jugs of conventional are way easier and faster when doing front/rear/trans in one go.