Mobil1 LS 75w90 in transfer case

[4OYOTER]

I read a thread recently where someone went to the extent of ordering the Toyota OEM specified transfer case fluid. I'm about to change the front, rear diff and transfer case fluid on my 5th gen. Has anyone EVER had a single issue with using Mobil1 LS 75w90 in all three?

I just used it in all 3 on my 4th gen, just wanting to double check before doing the same job on my 5th gen.

 

[coltm4]

There is another thread that sort of describes this but having read through a bunch of them, i'd say it depends on your low temps where you anticipate using it. From what I gather there is a triple cone synchronizer that works REALLY hard to get the chain, gears, driveshaft and half an axle shaft/components up to the same speed as the rear output shaft. What this suggests to me is 75w oil was carefully tailored to make those synchros work the right way in lower temps.

I recently had to use my 4wd repeatedly in cold weather and to say the shift is harder than normal is no joke compared to summer use and some of this difficulty I attribute to the cold temps and oil.

Could you get a away with it, yes and it may mean lower road speeds for shift on the fly in order to not damage things. For me I think I'm going to order the next closest thing: Ravenol 75w gear oil.https://www.amazon.com/RAVENOL-J1C1...TF8&qid=1484275628&sr=1-3&keywords=ravenol+75

Here is a good but long video showing the insides of your transfer case.

https://youtu.be/ESm0PPBkAQQ

 

[N2GLOCK]

I went thru this same fiasco a few weeks back. I've been involved in the automotive repair industry for 23 years now and I ended up going with the OEM fluid (as expensive as it is) My master tech recommended I NOT go w/ conventional diff fluid in the T/C. Even when I was planning on buying the most exotic sounding diff fluid he convinced me to go w/ the OEM

 

[Engineer]

I have no data to back this up but you will be fine with 75w90 in all three. Many, including myself have used this without issue.

I wont fault you for following the manual as that's what most people would reply when someone asks an interval change question but in this case I have only seen 1 person who blamed a failure on the oil and in that case It was a bearing IIRC.....very likely failed from another reason and not due to 75w-90being used but they claimed otherwise.

People under estimate the robustness of modern day vehicles and or mechanical assemblies....while its funny how a little voltage drop can cause a huge amount of issues its also amazing what kind of "abuse" they can and will take.

 

[TRUSTYAXE]

I'm doing the same to mine, both diff's and the TC. I tried finding the threads I read and failed, but I can tell you the moral of the story was use Toyota fluids.
An actual loss of MPG was reported when using the mobile one stuff in the rear diff on one thread and a Toyota mechanic was swapping back to the Toyota stuff after the original owner had just changed it to mobile one in another thread.

 

[N2GLOCK]

I'm doing the same to mine, both diff's and the TC. I tried finding the threads I read and failed, but I can tell you the moral of the story was use Toyota fluids.
An actual loss of MPG was reported when using the mobile one stuff in the rear diff on one thread and a Toyota mechanic was swapping back to the Toyota stuff after the original owner had just changed it to mobile one in another thread.

You'd be fine w/ Mobil 1 in the front and rear diffs. I recommend you go genuine Toyota in the T/C

 

[03_4x4Runner]

I used Mobil 1 in my 4th gen transfer case. Shortly after the switch my transfer case actuator seal started leaking. It started leaking at around 30k miles and when I traded it in at 72 k miles it was leaking a lot. This is a very expensive fix. It got so bad that it is one of the main reasons I traded it in on my 5th gen. The Mobil 1 may not have had anything to do with it but from now on I will only use OEM in there. I did use Mobil 1 in the difs with no problems and will do so again.

 

[catrains]

I'm doing the same to mine, both diff's and the TC. I tried finding the threads I read and failed, but I can tell you the moral of the story was use Toyota fluids.
An actual loss of MPG was reported when using the mobile one stuff in the rear diff on one thread and a Toyota mechanic was swapping back to the Toyota stuff after the original owner had just changed it to mobile one in another thread.

no on the rear diff oil comment . I just changed my rear diff oil with 3K miles on it.. oil was black and nasty. installed mobil 1 75-90wt .. now I get 19 MPG @70 MPH .. also drives with less drag when I take foot off throttle..

front diff not changed or transfer case because the gear oils looked perfect . rear diff was not good.. level was perfect so the break in did heat up the oil .. also the gear oil looked like conventional gear oil NOT synthetic so that maybe why I go more MPG...

SO I GOT 1.5 mpg INCREASE... 1500 MILE RIDE.....

 

[TRUSTYAXE]

Good to know, wish I had done my rear sooner. Your reporting better mpg while others reported worse so that remains fuzzy to me.

 

[catrains]

Good to know, wish I had done my rear sooner. Your reporting better mpg while others reported worse so that remains fuzzy to me.

I noticed when I backed off the ramps that the T4R rolled more. then I drive it around the block did some errands. drove much better less drag temp was 40 deg f.. a couple hundred miles later I began my trip to your area from up here in the cold north to FMB..before my change of the diff oil I got 17.5 MPG at lower hyway speeds .. I did the calculations when I got to exit 131 rt 75.. 1530 miles 19 MPG... I was doing 80 MPH on the rt 75 from Gainesville to FT Myers.. scan gauge also showed 18-20 MPG at that area/speed. temp 77deg f.. much better than 40 deg f LOL.. will be here till end of feb....

 

[03_4x4Runner]

no on the rear diff oil comment . I just changed my rear diff oil with 3K miles on it.. oil was black and nasty. installed mobil 1 75-90wt .. now I get 19 MPG @70 MPH .. also drives with less drag when I take foot off throttle..

front diff not changed or transfer case because the gear oils looked perfect . rear diff was not good.. level was perfect so the break in did heat up the oil .. also the gear oil looked like conventional gear oil NOT synthetic so that maybe why I go more MPG...

SO I GOT 1.5 mpg INCREASE... 1500 MILE RIDE.....

On my 4th gen the rear dif lube always looked dirty when changed. The front dif and transfer case always looked clean. I can not say I noticed any difference in MPG or performance after changing all three to Mobil 1.

 

[TRUSTYAXE]

I noticed when I backed off the ramps that the T4R rolled more. then I drive it around the block did some errands. drove much better less drag temp was 40 deg f.. a couple hundred miles later I began my trip to your area from up here in the cold north to FMB..before my change of the diff oil I got 17.5 MPG at lower hyway speeds .. I did the calculations when I got to exit 131 rt 75.. 1530 miles 19 MPG... I was doing 80 MPH on the rt 75 from Gainesville to FT Myers.. scan gauge also showed 18-20 MPG at that area/speed. temp 77deg f.. much better than 40 deg f LOL.. will be here till end of feb....

Well I already bought the fluids so I guess I will do Mobil 1 on the diffs next round. Welcome to sunny SWF. Tons of sugar sand to get stuck in off exit 179 if your ever up for it.

 

[LandCruiser]

I buy the stuff by the gallon because I also use it on my Land Cruiser.

I don't have a problem using it in differentials and transmissions of both vehicles.

 

[4OYOTER]

Thanks everyone for the replies. It sounds like the 75W might be a good idea for the transfer case in my 5th gen. Has anyone used the Ravenol 75W linked above? Sure seems like a good alternative to the Toyota brand. I will say it seems disappointing that most dealers don't use the 75W in the transfer case and just use whatever bulk is being put in the front and rear diffs.

Looking in my 4th gen manual I see that 75w90 is actually the recommended transfer case fluid, so I should be good to keep the Mobil1 in my 4th gen. It also seems the actuator leak issues seem to be on the earlier model 4th gens so I'm hoping it will never be an issue using the synthetic in my 2008.

 

[HerT4R]

I have no data to back this up but you will be fine with 75w90 in all three. Many, including myself have used this without issue.

I wont fault you for following the manual as that's what most people would reply when someone asks an interval change question but in this case I have only seen 1 person who blamed a failure on the oil and in that case It was a bearing IIRC.....very likely failed from another reason and not due to 75w-90being used but they claimed otherwise.

People under estimate the robustness of modern day vehicles and or mechanical assemblies....while its funny how a little voltage drop can cause a huge amount of issues its also amazing what kind of "abuse" they can and will take.

ive been using Mobil1 75W-90 Delvac in my diffs and tcase. No issues to date. No leaks and its been around 20-25k since i changes the oil.

getting ready to change the rear diff again due to the flooding in houston and a recent water crossing and going to use 75w-90 delvac again. then rear diff breather mod. but i trust the delvac. its been great.

 

[sandcrawler]

i'll be changing my TC fluid this spring and ponying up for the straight 75W (Toyota P/N 08885-81080). i don't care overly much that it's expensive; my labor cost is $0.

have been running Amsoil Severe Gear 75w90 in front and rear diffs for several years now, fwiw.

 

[veloindy]

Mobil1 in all 3, no issues over the last 50K miles.

 

[coltm4]

Thanks everyone for the replies. It sounds like the 75W might be a good idea for the transfer case in my 5th gen. Has anyone used the Ravenol 75W linked above? Sure seems like a good alternative to the Toyota brand. I will say it seems disappointing that most dealers don't use the 75W in the transfer case and just use whatever bulk is being put in the front and rear diffs.

Looking in my 4th gen manual I see that 75w90 is actually the recommended transfer case fluid, so I should be good to keep the Mobil1 in my 4th gen. It also seems the actuator leak issues seem to be on the earlier model 4th gens so I'm hoping it will never be an issue using the synthetic in my 2008.

I just ordered 2 quarts and should be here tomorrow. I decided on this for the viscosity specs and the aforementioned synchronizers. Also, need to avoid GL5 spec oils because they will corrode the synchronizers brass. Products listed as manual transmission fluids are usually rated GL4 which will not corrode brass.

 

[catrains]

I just ordered 2 quarts and should be here tomorrow. I decided on this for the viscosity specs and the aforementioned synchronizers. Also, need to avoid GL5 spec oils because they will corrode the synchronizers brass. Products listed as manual transmission fluids are usually rated GL4 which will not corrode brass.

gm used synchromesh gear oil in the manual transmissions that my family member had . 1994 chev S10 5 speed manual.. when we changed from dexron III to the GM synchromesh shifting was very smooth and the oil did have protection for the yellow metals..

previous owner had the dexron III in it hard to shift so we changed to the GM tranny oil..it worked ..

 

[4OYOTER]

I just ordered 2 quarts and should be here tomorrow. I decided on this for the viscosity specs and the aforementioned synchronizers. Also, need to avoid GL5 spec oils because they will corrode the synchronizers brass. Products listed as manual transmission fluids are usually rated GL4 which will not corrode brass.

Let us know how the Ravenol works out!