Diff and Transfer Oil

[Oldswagon]

I am due to change the differential and transfer case oil in my '08 Tundra. Last time it was done by the dealer so it likely has Toyota dino in there now.

The transfer case specs GL-3 75W-90. The diffs specify Toyota Genuine Differential gear oil LT 75W-85 GL-5 or equivalent. I am thinking of upgrading to a Synthetic as I see temps in the -30 C range and my truck sits outside all the time.

Any recommendations?

 

[dave123]

Redline

 

[Clevy]

Redline

 

[BISCUT]

M1 in my F150 and the Armada...

 

[Astro14]

M1 75W90 is both reasonably priced and reasonably available. I use it in my 4 Runner.

 

[Bandito440]

Originally Posted By: Astro14
M1 75W90 is both reasonably priced and reasonably available. I use it in my 4 Runner.

This is what I put in both differentials and the transfer case of my 2008 Tacoma. Can't complain.

 

[Kuato]

Vote for Amsoil here.

 

[Cold_Canuk]

Amsoil

 

[CharBaby]

GL-3 ?

 

[LotI]

Originally Posted By: Clevy
Redline

+1

 

[901Memphis]

Originally Posted By: Char Baby
GL-3 ?


Probably to protect syncros?

 

[supton]

Hmm, had to look, the 2009 manual I downloaded does list GL5 for diffs and GL3 for transfer. I thought it was GL5 for all myself. 2HI/4Hi can be disengaged/engaged up to 62mph. Although, the front diff has the same setup, so as to disconnect the front driveshaft.

 

[Oldswagon]

Does GL-5 supersede the GL-3 rating? It looks like GL-3 is hard to find. What about using a GL-4 fluid?

 

[camelCase]

Originally Posted By: Oldswagon
Does GL-5 supersede the GL-3 rating? It looks like GL-3 is hard to find. What about using a GL-4 fluid?


GL-4 will work just fine for a GL-3 specification. Some high grade automatic transmission fluids will do too.

GL-5 fluids have higher dosage of EP additives in them that will attack yellow metals. Only use GL-5 fluids in rear ends and other similar gear sets that call for them.

Using GL-5 in something requiring GL-4 or lower is not recommended.

 

[Oldswagon]

Sounds good. I will try to find a GL-4 rated gear oil for the transfer case. Anyone know of one?

 

[daleferd]

Check the manual and then pick a synthetic in that wt.

 

[Oldswagon]

I already did, as I mentioned the specs in my first post. I already have several good options outlined here for a GL-5 for the diffs, but I am looking for a GL-4 for the transfer case.

 

[INDYMAC]

You can use whatever you use in the front diff in your t-case. Page 680 in your owners manual says 75w-90 gl4 or 5 for t-case. GL5 for diffs. I don't think there is any reference to gl3, because there is no such thing in the API inventory.

 

[jake88]

GL-4 is no longer an active spec. If there is any worry about brass/yellow metal parts in your t-case, I would suggest a 75W-90 fluid meeting API MT-1. The MT-1 spec is an upgrade on the GL-5 spec, which includes more stringent copper corrosion protection.

If you find an MT-1 fluid you trust, you can use it in the diff and the t-case. You may have to add some differential friction modifier for the axle if you have a locking differential. Just depends on what gear oil you buy - some are pretreated with friction modifier.

 

[Oldswagon]

I got the info from my service manual. I didn't check the owner's manual. Your Tundra is newer, so maybe Toyota updated the specs.

I didn't realize that GL-4 is not longer active too. I thought this was only the case for GL-3. I am not sure if there is any yellow or brass parts in the T-case. I will have to look into that.