I'm getting ready to replace all three (front, center/transfer, rear) differential fluids and would like a clarification on the oil type. I'm planning to use Mobile 1 75W90 synthetic, but there is a regular version and a LS (Limited Slip) version. My question is should I put LS version on all three, just the rear or just the front and rear? Thanks.

 

Only the center diff is an LSD type diff, but I'm pretty sure even it takes regular (non-LS) gear oil. Front and rear diffs are open on the GX470.

 

Our center diff doesn't use clutch packs so you're fine using standard 75w90 gear oil.

Make sure you remove the fill bolts first before draining any oil.

 

Thanks for your replies. So I am fine using either the regular or LS version of the gear oil on all three differentials, correct?

 

If you've already bought the oil you'll probably be find but if not there's no reason to buy an oil w/ LS additives in it since we don't have clutch plates.

 

You should be using the regular version, not the LS version with the friction modifier the LSD clutch packs need. I'm sure it won't harm anything using the LS version, but that's not what you should be using.

 

Here are the specs and the refill procedure.. Hope this clears your doubt.

 

^^Does that indicate that LSD was an option on the GX470?!?^^

 

Nope, our GXs did not come with LSDs and it was never an option:
http://www.lexus.com/contact/pdf/2005/2005GXspecs.pdf
(change the year in the link above to see different years)

The center diff uses a torsen type limited slip. The front / rear diffs uses ATRAC that uses the brakes to act like a limited slip. As you can see below there are no clutch plates in either the front or rear diff so we do NOT have LSDs.

Front Diff


Rear Diff

 

How many bottles of oil you getting to do all 3?

 

That was my understanding as well, but the docs Mann777 posted look to be GX470 specific, and seem to indicate the LSD sticker on the rear diff is something you should watch for. Weird.

 

I bought 7 bottles of Mobil Synthetic gear lube with LS (limited slip) LS 75W 90 bit messy job, so there was some spill.

I USED THE SAME OIL ON FRONT DIFF, REAR DIFF, AND TRANSFER CASE. 2004 GX. (RC OR mann777, AM I OK DOING THIS?)

Check out MANN777 link, he covers front and back diff. The transfer case is not included in the link but very easy to do.
https://www.clublexus.com/forums/gx-...-tutorial.html

 

You'll need 7 quarts total:

• Front Diff: 1.5qt.
• Transfer Case: 1.5qt.
• Rear Diff: 3.15qt.

It's not GX specific, or I should say the picture of the LSD sticker isn't. It's saying that's how you tell in general on a Lexus / Toyota if the rear diff has a LSD. In the Tundra shop book it shows the exact same picture.

There's no LSD for our GX, our GX uses ATRAC (uses the brakes) as a limited slip for the front and rear diffs.


I'm using Amsoil 75w90 severe gear and it says it's safe for open diffs and LSDs. It says if you have an LSD and you heard clutch chatter to add one of their friction modifiers.

As long as it's a Hypoid / API GL-5 oil (that's exactly what it shows in the shop manual for the front / rear diff and transfer case) you're fine using it and on Mobil 1's site it says:

"Mobil 1 Synthetic gear Lubricant LS 75W-90 is intended for initial fill, topping-off or refilling differentials, final drives, transfer cases and other gear applications where lubricants meeting API Service GL-5 and multi-purpose or mild EP gear lubricants are recommended"

LINK ---> http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_Synthetic_Gear_Lubricant_LS_75W-90.aspx

 

Thank you RC!

 

Thanks everyone. Great information. Mann777, I was able to find the doc you noted after I posted my question. Looks like Lexus changed the fluids to synthetic beginning MY 2008. However, at around $50 quart, I will stick with Mobile1!