Amsoil looked good in front differential

I recently changed the fluid in the front differential that had Amsoil Severe Gear 75-90W in it for the last 30,000 miles. That stuff looked brand new when it was draining out. A mechanic buddy that let me use his lift to change the oil even commented on it. The time before last I had Toyota do both differentials and the transfer case. The Toyota oil looked pretty bad in the front differential when I drained it to put Amsoil in. Almost a milky color and very dirty. I'll be changing all the fluids in my Tacoma myself from here on out and using the good stuff!

 

I enjoy folks who visually rate the condition of lubricants. Makes all those ChemE's seem so unneeded.

Using any lubricant of the correct viscosity, API rating and change interval based on vehicle usage will get you a healthy drive line. No boutique lubricant's needed.

 

Good feedback. However, I think the rear diff would paint a better picture since the front diff usage varies tremendously. Some folks may only engage the front a couple times in 30K. Any word on the rear?

 

The transfer case and the rear differential looked good with both the Toyota oil and the Amsoil. I remember other Tacomaworld members also noticing the milky color of the front diff fluid in another thread. I know my oil observations might not be that scientific, but there was sure a difference in appearance.

I paid Toyota $160 to change the fluids in both diffs and the transfer case. When I did it myself I spent $100 on full synthetic oil. I just feel better about saving money and using the good stuff.

 

Toyota's oil itself looks slightly murky. Doesn't mean anything.

 

Just don't go putting mobile 1 gear oil into a manual transmission. I did that ONCE, and regretted it -- stuff is more viscous at low temperatures than it should be, causes synchros not to... synch.

 

I had the same issue at 30k. Front diff was milky, the rear and t case were clean. Have amsoil severe gear in all three now.

 

For transmissions that call for GL4 (like ours) the

$34 Ford XT-M5-QS Full Synthetic Manual Transmission Fluid - 1 Quart , black

Ford XT-M5-QS is an outstanding product.

Available OTC at a Ford dealer. They 'may' have to order it, as it's usually found at dealers that carry some of the SVO line of goods.

It's pricey, but worth every penny. Seen many a notchy shifter on some fussy sports cars smooth up a ton after going to this.

In my own case, I had OE fluid, Redline MT90, then RP. Couldn't really tell a difference in any of those. Not that my shifting in that car was bad, just wanted better.

The Ford stuff did it.

YMMV of course.

 

Can't beat Amsoil.. I use their motor oil too. I get 20k miles between oil changes and it still looks new when I change it.

 

The book actually specified GL4 *OR* GL5.
See page 482: http://www.toyota.com/t3Portal/document/om-s/OM35A51U/pdf/OM35A51U.pdf

That ford oil is probably slightly lower viscosity (i.e., not necessarily outside of spec, just on the "thin" side). You could probably get the same results by mixing a small portion of MT 5w30 into the 75w90. Like this stuff, for instance; http://www.amsoil.com/shop/by-produ...omesh-transmission-fluid-5w-30/?code=MTFQT-EA

 

Make sure that you're doing occasional oil analysis on what comes out at that kind of OCI. I'm sure that the oil is good oil, but that is a VERY long time.

 

So did the vehicles I / we used it in.

Nope. Talking same viscosity, just different APIs.

High mileage tear downs in these transmissions showed much less syncro wear in ones running 4, due to the dislike bronze has for GL5. And several with synro failures that had been feed 5 all their lives.

We're talking regular 30k changes too, not maintenance neglected units.

There are very few GL4 products available. Redline and RP made 2 of the ones I used. Most products are rated 4/5.

The Ford product I quoted is a GL4 also. It's 'magic' is a different additive package. My tribologist friends tell me they feel quite comfortable moving to 50k change intervals, regardless of time, even in a weekend raced environment, based on multiple lab tests.

 

my front diff looked great with the stock oil after 30k, same with transfer

 

You didn't read what I read, did you?
A viscosity spec on the side of a bottle isn't an exact figure. 90 represents the mid point in a range. Anything within the range will qualify as 90. So, for example, anything from 85 to 95 will qualify as "90". The ford oil is probably closer to the 85 side of things. Mobile1 is probably closer to the 95 side of things. Amsoil/redline/toyota probably closer to the middle.

I'm sure that this is also true.

But consider this;
The Mobile 1 crap I tried worked perfectly fine (smooth shifting) when it was warm (installed it in south florida, where it worked fine, then drove back to Canada, where it was NOT fine). It only exhibited the bad behaviour when it was COLD. The temperature doesn't change an oil between GL4 and 5, nor does it alter the additives. The only difference that the temperature makes, is viscosity.