1st change of transmission & transfer case fluid(s)

[GT3Tim]

Its a turbo thing.

Porsche recommends the same thing.
Plugs every 40k.

My Porsche (2021 Cayenne GTS) is every 30K...I have a tune on it too, so it's even more important to stick to that interval, or less.

 

[Warrantero]

I am doing my diffs and xfer case at 15 k to dump all the break in metals out. May be overkill but it’s worth it to me. Using AMSOIL for the diffs and liquid moly for the xfer case.

 

[Bret_T]

Please let us know how the old fluids looked when they were drained.

 

[Warrantero]

Here goes, my GX has 16706 miles, just did the front/rear diffs today, have liquid moly 75W on order for the transfer case.

Dropped the spare tire made it a lot easier to drain and fill. Need a 24 mm socket to remove. Man it was tight! Cripes! Used AMSOIL 75w-85. Squeeze bags worked well on rear diffs. Used a little over 7 qts.

Front diff you will need a 10mm Allen socket for the fill and drain plugs they are torqued down too, it took a bit to break them loose.

Front and rear Drain plugs had a little bit of material on it looked alright to me.

Recommend a fluid pump for the front diff not much room to get a squeeze bag in there. I don’t have a lift so I removed the skid plate and gave me room to work. Just shy of two quarts to fill.

Looks like the transfer case is a 10 mm socket to remove fill and drain plugs. You will need a fluid plump for the transfer case also.

I tightened plugs to 20ft lbs, seemed to be pretty snugged down.

12157-10010 and 90430-24017 are the parts numbers for drain and fill plug gaskets on the front differential.

12157-10010 is the part number for drain and fill plug gaskets on rear differential.

Transfer case drain and fill plug gaskets are 90430-18008. Hope this helps.

 

[Bret_T]

Any thoughts on using the more available 75W-90 GL-5? 75W-85 GL-5 is difficult to find and over twice as expensive.

 

[Warrantero]

You would probably take a very small hit in gas mileage, as long as it meets the spec. I used amsoil to meet the 75w-85 spec.

 

[1mikezat1]

I spoke with a retired Toyota/Lexus master mechanic a while ago and asked for his advice regarding gearbox and transfer case fluids.

According to him, gearboxes and transfer cases, especially those manufactured in Japan, tend to have very tight internal gear tolerances when new. Because of this, fluid selection during the early service intervals can be important.

For vehicles operated under what Toyota considers "special driving conditions," such as frequent short trips under 5 miles, heavy stop-and-go traffic, extensive idling, towing, driving in extremely hot or cold temperatures, or operating on dusty or unpaved roads, he did not recommend using 75W-90 gear oil for the first two fluid changes. His concern was that the higher viscosity could create additional resistance, not being able to "sneak" in required volume between moving parts, and potentially generate extra heat during the initial break-in period.

For normal street driving, he recommended staying with Toyota OEM fluid for the first gearbox and transfer case fluid change. For the second change, he suggested that a fluid such as Amsoil or Ravenol 75W-85 would be acceptable.

After the first two fluid changes, he said the choice between 75W-85 and 75W-90 becomes less critical, and that using 75W-90 afterward should not present an issue.

My recommendation is to do the gearbox and transfer case fluid changes yourself if you are comfortable doing the work, but buy Toyota OEM fluid directly from a dealer. OEM fluids are ridiculously expensive, but if you do the work yourself, the pain is much less. Do not buy OEM fluids from Amazon or eBay; there are too many counterfeits.

 

[Bret_T]

Thanks for the information. I'll stick with the 75W-85 GL-5. I looked back at my old 2017 Land Cruiser maintenance records. It turns out that I used both Ravenol and Red Line 75W-85 GL-5. Since I never had an issue with that vehicle, I'll go with the Red Line again. I just can't stomach the ripoff price for the Toyota 75W-85 GL-5. I have a partial quart of the Red Line left and the bottle label indicates that it meets the Toyota specification.

 

[Warrantero]

Thanks for the information. I'll stick with the 75W-85 GL-5. I looked back at my old 2017 Land Cruiser maintenance records. It turns out that I used both Ravenol and Red Line 75W-85 GL-5. Since I never had an issue with that vehicle, I'll go with the Red Line again. I just can't stomach the ripoff price for the Toyota 75W-85 GL-5. I have a partial quart of the Red Line left and the bottle label indicates that it meets the Toyota specification.

I used the AMSOIL 75w-85 GL5 and went with Redline MT/ML 70/75 which meets the Toyota LF spec per Redlines website. I was going to use Liquid Moly but the Redline was available locally.