2019 Lexus GX460 front diff, 55k mi; Motul 300 Gear 75w-90 GL5, 39k mi

[sds911]

Here is the UOA from Cat Labs on GX460 front differential using Motul Gear 300 75w90 for approximately 39k miles. Viscosity thickened from 14.2 for new to 14.7. Front diff fill is a bit less than rear - 1.5 to 2 qts in front vs. 2.5 to 3 in rear diff iirc.

Rear diff UOA of Motul sheared to 12.3. Will see if I can find a blackstone report to compare universal avg. But, wear metals look ok to me for 39k run.

Did not do UOA on Lexus factory fill 75w85 gl5 for front differential drained at 15,800 miles or so. So, can’t compare as I did with rear diff factory fill.

Feel free to comment and provide analysis. Think it looks better than rear diff and smaller capacity in front diff.

 

[fantastic]

Now you have some data on your gear fluid. BS might give you that average.

 

[Jetronic]

Did you have an analysis done on the virgin fluid, it might have been 14.7 to start with. You can't go off the datasheet values, which are averages. 10% more or less is considered in spec.

 

[sds911]

Did you have an analysis done on the virgin fluid, it might have been 14.7 to start with. You can't go off the datasheet values, which are averages. 10% more or less is considered in spec.

No. I didn’t do VOA. Just going by Motul spec sheet and possibly looked at VOAs by other(s). It was late last night - memory is fuzzy.

 

[Jetronic]

No. I didn’t do VOA.

Then I would assume the viscosity is still where it started, it's within 3% or so of the datasheet viscosity... ie noise. And viscosity measurements aren't that precise either.

In other words, the UOA numbers are better than you first thought.

 

[sds911]

Then I would assume the viscosity is still where it started, it's within 3% or so of the datasheet viscosity... ie noise. And viscosity measurements aren't that precise either.

In other words, the UOA numbers are better than you first thought.

Nice.

 

[edyvw]

Nice.

This is a really good report, and an overkill change interval.
Gear 300 is probably one of the best, if not the best gear fluid.

 

[martinq]

This is a really good report, and an overkill change interval.
Gear 300 is probably one of the best, if not the best gear fluid.

Agreed. Right up there with Amsoil, HPL and Red Line, etc.

If you want to optimize your maintenance I would do a VOA on this fluid along with the next UOA.

 

[sds911]

Manual calls for 60k changes to TC and potential 30k on diffs if towing, car top carrier etc. I do have roof rack and use large thule roof box. But, yes could extend oci on diffs now that break in is over. Will do uoa w/o draining at 40 to 50k miles on current Valvoline diff fill. Next fill probably Motul, Delvac or Amsoil SVG!

 

[sds911]

This is a really good report, and an overkill change interval.
Gear 300 is probably one of the best, if not the best gear fluid.

Believe me I know. I’ve used Motul products before in my other vehicles. I was curious how it would hold up in the GX460 diffs - given the full time 4wd, heavy curb weight, hot/humid weather in TX and my lead foot on hwy trips.

I tend to think of Motul products for sporty applications like WRX, 911, Bmw etc. I’m sure the Motul 75w90 offers excellent protection compared with the Lexus factory fill 75w85. Would use again if on sale. But, I’m really considering Delvac 75w90 or SVG next. A gallon of Delvac was $32/$35 per gallon on sale at Napa last time I checked. Will see how the current Valvoline FS does in 40 to 50k miles - also on sale frequently.

 

[edyvw]

Believe me I know. I’ve used Motul products before in my other vehicles. I was curious how it would hold up in the GX460 diffs - given the full time 4wd, heavy curb weight, hot/humid weather in TX and my lead foot on hwy trips.

I tend to think of Motul products for sporty applications like WRX, 911, Bmw etc. I’m sure the Motul 75w90 offers excellent protection compared with the Lexus factory fill 75w85. Would use again if on sale. But, I’m really considering Delvac 75w90 or SVG next. A gallon of Delvac was $32/$35 per gallon on sale at Napa last time I checked. Will see how the current Valvoline FS does in 40 to 50k miles - also on sale frequently.

Delvac 75W90 is favorite among Porsche owners.

 

[4WD]

Believe me I know. I’ve used Motul products before in my other vehicles. I was curious how it would hold up in the GX460 diffs - given the full time 4wd, heavy curb weight, hot/humid weather in TX and my lead foot on hwy trips.

I tend to think of Motul products for sporty applications like WRX, 911, Bmw etc. I’m sure the Motul 75w90 offers excellent protection compared with the Lexus factory fill 75w85. Would use again if on sale. But, I’m really considering Delvac 75w90 or SVG next. A gallon of Delvac was $32/$35 per gallon on sale at Napa last time I checked. Will see how the current Valvoline FS does in 40 to 50k miles - also on sale frequently.

I get Delvac 1 at Summit Racing - and order that and/or enough stuff for free shipping … They have other Delvac products you don’t see in box stores …