I've been researching the Lexus specification for our rear differentials and available fluids that match the spec.

I was able to find information on the message board (here: https://www.clublexus.com/forums/ls4...-gear-oil.html) that there was a TSB recommending that our vehicles use the following part number for OEM fill:

Toyota Genuine Differential Synthetic Gear Oil (P/N 08885–02506) API GL–5 SAE 75W–85 or equivalent

I also found this product which appears to be the OEM stuff but is only semi-synthetic:

http://jaytec-lubricants.com/index.p...roducts_id=112

I was also able to find a .pdf of the actual TSB and a related TSB discussing the fluid (attached).

Looking at the aftermarket, I found a full synthetic Redline product that appears to be directly formulated for Toyota use/vehicles. What does everyone think of it for use in our LS430s?

http://www.redlineoil.com/product.aspx?pid=40&pcid=4

Last question, in the manual, some vehicles are specified to use the synthetic fill and others a "hypoid" fill - as noted on the differential itself - does anyone know what the differences are in the differentials and/or if the GL5 listed above can be used in both applications or the synthetic application only?

Thanks,

Andrew

 

I replaced mine with Mobil 1 synthetic. The drain part is easy, however you have to replace the fluid into the top of the differential and will need a pump of some sort as the bottle won't fit up there to pour the new fluid in. I used a 60cc syringe with a plastic tube attached to the end. A friend of mine bought a hand pump at an auto supply store and we used that to replace his fluid.

 

Thanks for the response. I've been considering using Redline 75-90 full synthetic which is the original weight. I still don't fully understand why Lexus issued their TSB to drop to a 75-85. I suspect, and have read, that their newer vehicles are using the lighter weight oil to help improve fuel economy. I'm thinking that I am more concerned with the long term longevity of the differential than a very slight improvement in fuel economy and will likely just stick to the original spec. I've previously had some bad experiences with the Mobil1 brand and, although I guess their product may be good, I will certainly go with something else. All suggestions welcome.

Andrew

 

I discovered by accident that Toyota/Lexus RWD differentials have an interesting wear characteristic... if you don't change the fluid they seem to last just fine BUT they become limited slip in function!

You read that correctly. I actually changed my LS400 fluid at the suggested interval of (IIRC 75k miles) but did not after that and have 168k trouble free miles. Not sure when it happened but knowing that earlier higher mileage cars would often spin both tires ala LSD I checked out my own and sure enough two black stripes.

I postulate this is due to the shape of the spyder gear to case interface that seem to increase in friction over time as they wear in together. I don't see this creating a problem and cannot recall a failed differential so it is up to you but for me... free limited slip is a GOOD thing.

 

Anyone have the torque specs on the drain & fill plugs? Also, are there crush washers that needs to be purchased?

Brian

 

Yes, I believe crush washers are required. Also, please find attached the FSM details for the change (including torque for the bolts).

Andrew

 

Thanks!

Brian

 

ABS,

I just had my Lexus dealer replace my differential fluid today on my 05 LS430... They used Valvoline VV70027. 75W90, full synthetic. Charged me for 3 quarts @ $14.35 per quart. As far as the gaskets for the plugs, two are required, one for the drain and another for the fill, they are part #: 12157-10010 @ $1.52 each from the local dealer. All in, including $60 in labor, they charged me $106.09 for this.

http://www.drillspot.com/products/66...hetic_gear_oil

 

Looks like a very high quality lube.

I guess they are ignoring the 75w-85 TSB? No worries, I am also going to ignore it by using Mobil1 75W-90 synthetic.

Some more info on the Valvoline:

http://www.valvoline.com/products/co...d-gear-oils/81

and

http://www.valvoline.com/pdf/HDSYNGO.pdf

 

Looks like they gave me a decent product for the differential...

BTW, I was going to start a new post about transmission fluid, but since the most recent threads have gotten so heated, I'm going to hold off for a bit. I'll state here though that I had my 05's transmission fluid exchanged at the dealer today along with the diff fluid. 8 quarts of WS fluid. 00289-ATFWS... They also charged me for two gaskets, part #: 35178-30010 (just crush washers)... The magnet(s) in the pan were clean / no sign of any metal shavings.

I gave them a Blackstone Laboratories vial for them to fill with the old tranny fluid. I heard when I went to pick up the car, that the mechanics got a chuckle out of it, but they're very interested in me sharing the analysis results with them. I plan to send it off to Blackstone tomorrow for analysis. My 05 had 100,944 miles on it today when the fluid was changed. I'll post the Blackstone report when I receive it, then everyone can quickly argue over the validity of the test and results, before the moderator needs to close the thread!

My tranny was shifting fine, just felt compelled to have it done. I must say that it does shift a bit smoother through the gears and shifting from park to drive, park to reverse, drive to reverse, and reverse to drive, feels slightly smoother and faster.

 

I gather a 1999 has a larger set of nads than my 1992 or 2002? While seemingly quick for luxury sleds, mine have never dreamed of darkening the pavement like that! Free LSD, or not!

 

This posting caused me to check and see what my dealer did a year ago when the differential oil was changed at 50,000 miles (at their recommendation).

They used the Toyota Synthetic Oil recommended in the TSB and charged me $60.

 

I changed the differential oil on a 04 LS 430 last year for a neighbor with valvoline synthetic. It only took 2 quarts to refill and all of 15 minutes from start to finish in the driveway. The crush washers looked fine but replaced them anyway as the drain and fill bolts were torqued beyond belief. Total cost was about $15.00 for oil and washers.

 

I have two sample kits on order from Blackstone Labs too - guess what fluids they are for?

 

I'm assuming you had to jack up both the front and rear of the car to keep the differential level for filling purposes?

Andrew