suggestions for front diff gear oil (1 Viewer)

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Whats the best fron diff gear oil/weight?
 
From the 1997 Land Cruiser Owner's Manual (OM)

Oil type:
Hypoid gear oil API GL–5
Recommended oil viscosity:
Above—18°C (0°F)
SAE 90
Below—18°C (0°F)
SAE 80W or 80W–90

Should be the same for your 1992 but you should open it up to the "Specifications" section and double check. If you don't have the Owner's Manual then you should get it. It costs $10 and about 10 minutes of your time using the TIS web site. Spend a few more hours and you will have the complete Factory Service Manual (FSM), the Electronic Wiring Diagram (EWD) and any other Toyota or Lexus manual that you want. Quite a deal huh?

-B-
 
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The FAQ lists some good synthetics.

75w-90
Mobil1 is the winner for price-performance ratio
Redline is also good.
Amsoil good too supposedly

80w-90 non-synthetics:
Chevron Delo is great, but hard to find. Has to be bought in pails.
Any name-brand should be good. I used Valvoline. While I don't love valvoline products, the biggest deal is to make sure you have full diffs rather than dry, regardless of oil, and you should be good
 
Dyno comparison: Royal Purple Video Player

I would say synthetics perform better all around. I have run Royal Purple 75w90 in my diffs for years.

Mobil One tranny oil and, until recently, engine oil. I switched to Quaker State Synthetic because of availability and price.
 
I've gone with Royal Purple 75w-90 mixed 50/50 with Lucas Heavy Duty Oil Stabilizer. This time I tried all Lucas products, works great so far. Using the oil stabilizer has reduced gear noise considerably.

Just my two cents!
 
Royal Purple 75-90W:smokin:
DSC00212.JPG
 
I read a gear oil review that compared like 30 gear oils, and royal purple was one of the worst actually. Go figure.
I read through that test and though Royal Purple didn't do as well in some tests it was a good performer in other tests. Some of the tests are designed to detect potential shear breakdown of conventional oil which is much less of a problem for synthetic oils.

Having said that, the Amsoil seemed to do well in all the tests. I should research this further for my upcoming gear lube change.
 
I read through that test and though Royal Purple didn't do as well in some tests it was a good performer in other tests. Some of the tests are designed to detect potential shear breakdown of conventional oil which is much less of a problem for synthetic oils.

Having said that, the Amsoil seemed to do well in all the tests. I should research this further for my upcoming gear lube change.

I'm sure it's a "test" paid for by Amsoil. If you notice, Mobil1 was "second" and it's significantly cheaper and far more available. Plus, you don't have to buy it in some Amway like pyramid scheme.

Anyway, fresh clean oil with no water in it is what you want. Change your gear oil after you've been in water over the axles whether it's synthetic or conventional, and you will likely never have a differential failure in your entire life.

I mostly use coastal 80w-90 and change frequently.
 
I think that sometimes we over pamper our trucks. I have seen vehicles in some of the undeveloped countries that spend their whole life without a change of the gear oil and nothing happens to their transmissions or gears, and some are 4x4s used daily in some of the worst conditions. In some of these places they have no idea or they cannot afford these expensive oils, and the vehicles get used and abused daily. We forget that Land Cruisers were designed originally to be used in some of the worsts environments. However we do what we can to make our vehicles to last way beyond their expected life and I believe that regardless it is Mobil One, Amsoil, Royal Purple, etc. all these oils are good enough to get the job done, it is a matter of our personal taste and loyalty to certain brands. Like Cruisedrew said, all you want is fresh, clean oil.:cheers:
 
I think that sometimes we over pamper our trucks. I have seen vehicles in some of the undeveloped countries that spend their whole life without a change of the gear oil and nothing happens to their transmissions or gears, and some are 4x4s used daily in some of the worst conditions. In some of these places they have no idea or they cannot afford these expensive oils, and the vehicles get used and abused daily. We forget that Land Cruisers were designed originally to be used in some of the worsts environments. However we do what we can to make our vehicles to last way beyond their expected life and I believe that regardless it is Mobil One, Amsoil, Royal Purple, etc. all these oils are good enough to get the job done, it is a matter of our personal taste and loyalty to certain brands. Like Cruisedrew said, all you want is fresh, clean oil.:cheers:

Well said. I'm not sure if I'm loyal or not: Mobil 1 in the engine, Amsoil in the transmission, and Redline in the transfer case and diffs.
 
We should realize that each company is going to publish studies demonstrating that their product is superior than the competition. Iam not too loyal, only to the motor oil. Being using Mobil One for may years, even in a 1985 dirt bike that I have never taken the engine apart (no need yet). When it comes to transmission and gear oil I go mixed. I have used from cheap ATF to Amsoil. Now I found these bottles of Royal Purple for $8.00, I don't know how much it goes in the states, but here is normally $15.99 a bottle, so I think is worth the try. Unless I put the truck to some exterme wheeling (water), that gear oil will stay there for a long time.:cheers:
 
amen. all those using royal purple/amsoil are so anal they are going to change it often anyway.

Actually I use that stuff because I don't change it very often. 2 years on engine oil (waaaay less than 10k miles in 2 years) and I may never change the transmission or diffs again as I just don't put the miles on the LC.
 
amen. all those using royal purple/amsoil are so anal they are going to change it often anyway.

I change it with Royal Purple now and maybe 5-7 years from now (if I haven't sold the truck or go under water) so I don't think its being anal, its saving money on the long run. I pay $8.00 for a bottle of Royal Purple vs the regular stuff around 3-4 bucks that's going to be changed often... once a year? Do the math.:hmm:
 

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