FZJ80 Diff and Transfer Case fluids (1 Viewer)

[Lyle Kilson]

Forgive me if this question has already been answered but I’m doing my diffs and t-case fluids for the first time and want to make sure I do it right. I live in southern Utah where temps rarely get below 20 degrees but it can get well above 100 degrees in the summer. I was planing on using a Amsoil 75w-90 Severe Gear Synthetic oil for both diffs and the t-case. Is the 75w-90 the right weight for my climate? Does the T-case need something different than the diffs?

Thanks

 

[BILT4ME]

Forgive me if this question has already been answered but I’m doing my diffs and t-case fluids for the first time and want to make sure I do it right. I live in southern Utah where temps rarely get below 20 degrees but it can get well above 100 degrees in the summer. I was planing on using a Amsoil 75w-90 Severe Gear Synthetic oil for both diffs and the t-case. Is the 75w-90 the right weight for my climate? Does the T-case need something different than the diffs?

Thanks

@jonheld can advise on that brand. He knows it well.

 

[deltapine1]

I run conventional oils. 75w140 in the xfer and 80w90 in the diffs.

I have had a lot of seals in all types of vehicles start leaking when changed over from conventional oils to synthetics.

 

[Lyle Kilson]

I run conventional oils. 75w140 in the xfer and 80w90 in the diffs.

I have had a lot of seals in all types of vehicles start leaking when changed over from conventional oils to synthetics.

I didn’t consider the potential leaking. Thanks!

 

[deltapine1]

The xfer case holds 1.8 qts.

When you think about the weight of our 80s and the heat the tranny and xfer case develop that is not a large volume of fluid. I would use a name brand gear oil as they have more heat stabile wear additives in larger ppms than the generic and parts house brands. Castrol and Valvoline still use old modified formulas of MT1 gear oils to create the GL4/GL5 hypoid gear oils. Both have good EP additives.

I would run Red Line products if I had time to put new seals in everything. I made the statement today after 500 miles logged in the 80; "I could get a lot of work done if I could work on the 80 while I was driving."

 

[Lyle Kilson]

The xfer case holds 1.8 qts.

When you think about the weight of our 80s and the heat the tranny and xfer case develop that is not a large volume of fluid. I would use a name brand gear oil as they have more heat stabile wear additives in larger ppms than the generic and parts house brands. Castrol and Valvoline still use old modified formulas of MT1 gear oils to create the GL4/GL5 hypoid gear oils. Both have good EP additives.

I would run Red Line products if I had time to put new seals in everything. I made the statement today after 500 miles logged in the 80; "I could get a lot of work done if I could work on the 80 while I was driving."

Thanks man I really appreciate your insight. So the Castrol and Valvoline are your recommendations? Unless replacing seals should I stay away from synthetics like Red Line?

 

[deltapine1]

Thanks man I really appreciate your insight. So the Castrol and Valvoline are your recommendations? Unless replacing seals should I stay away from synthetics like Red Line?

Correct based on my experience. Others may have had great success with synthetics.

 

[cme4lyt]

Forgive me if this question has already been answered but I’m doing my diffs and t-case fluids for the first time and want to make sure I do it right. I live in southern Utah where temps rarely get below 20 degrees but it can get well above 100 degrees in the summer. I was planing on using a Amsoil 75w-90 Severe Gear Synthetic oil for both diffs and the t-case. Is the 75w-90 the right weight for my climate? Does the T-case need something different than the diffs?

Thanks

I use exactly what you plan on in mine, have for over 5 years, and very happy with the results. I’m a huge Amsoil fan and I usually run oil for 2 years, about 10000 miles in my case, before I change. I believe you can go with longer intervals but I’m a firm believer in changing oil as frequently as one can afford.

Regards,

 

[jonheld]

Forgive me if this question has already been answered but I’m doing my diffs and t-case fluids for the first time and want to make sure I do it right. I live in southern Utah where temps rarely get below 20 degrees but it can get well above 100 degrees in the summer. I was planing on using a Amsoil 75w-90 Severe Gear Synthetic oil for both diffs and the t-case. Is the 75w-90 the right weight for my climate? Does the T-case need something different than the diffs?

Thanks

I've been running Amsoil products for over 2 decades now. I simplify my stock by keeping 1 gear oil and 1 grease for everything. The 75w-90 is all I've used in both trucks for 100s of thousands of miles. The first number in a multi-grade oil is the cold viscosity. The second number is the final viscosity at operating temperature. So a 80W-90 and a 75W-90 are both 90 weight at operating temp. The 75 just flows a little bit easier when cold. IMO, insignificant.

I keep a case of the moly grease for everything that requires grease. PRODUCT CODE: GPOR2CR
I use the ATF in the tranny and PS system. PRODUCT CODE : ATFQT
I use the 10W-30 motor oil. PRODUCT CODE: ATMQT (only Toyota oil filters)

They do keep changing the packaging and product codes which makes me a little crazy.

 

[leonard_nemoy]

I have used Lucas 75w-90 in my Rigs for 10+ years. I am also in Saint George. My rig sees anywhere from below 0F to 115F ambient air temps.

Being in Saint George you can see quite a difference in temps and conditions just by traveling an hour or two. Ice fishing at 9,000ft to wheeling the Grand Canyon at 2,000ft in the summer. Or snowboarding on a Saturday and wake boarding the next Sunday.

 

[Lyle Kilson]

I have used Lucas 75w-90 in my Rigs for 10+ years. I am also in Saint George. My rig sees anywhere from below 0F to 115F ambient air temps.

Being in Saint George you can see quite a difference in temps and conditions just by traveling an hour or two. Ice fishing at 9,000ft to wheeling the Grand Canyon at 2,000ft in the summer. Or snowboarding on a Saturday and wake boarding the next Sunday.
View attachment 2551157View attachment 2551158

Thanks for the reply I really appreciate it. If you’re living in Saint George I may bug you from time to time about some question as I am really new to this LC life. Cheers!

 

[Lyle Kilson]

I've been running Amsoil products for over 2 decades now. I simplify my stock by keeping 1 gear oil and 1 grease for everything. The 75w-90 is all I've used in both trucks for 100s of thousands of miles. The first number in a multi-grade oil is the cold viscosity. The second number is the final viscosity at operating temperature. So a 80W-90 and a 75W-90 are both 90 weight at operating temp. The 75 just flows a little bit easier when cold. IMO, insignificant.

I keep a case of the moly grease for everything that requires grease. PRODUCT CODE: GPOR2CR
I use the ATF in the tranny and PS system. PRODUCT CODE : ATFQT
I use the 10W-30 motor oil. PRODUCT CODE: ATMQT (only Toyota oil filters)

They do keep changing the packaging and product codes which makes me a little crazy.

Thanks for the specifics that really helps me out!

 

[Lyle Kilson]

I use exactly what you plan on in mine, have for over 5 years, and very happy with the results. I’m a huge Amsoil fan and I usually run oil for 2 years, about 10000 miles in my case, before I change. I believe you can go with longer intervals but I’m a firm believer in changing oil as frequently as one can afford.

Regards,

It’s good to know other people are using these products. Thanks for your response!