Rear diff oil analysis

[toyo]

I had my rear end oil checked. I changed out the factory fluid at 15k and put in Mobile1 synthetic. Here is my report with 15k miles on the new oil.

 

[greasefingers]

That is a valuable report and a rare document to have. I just changed my diffs and found that the drain plugs had about a 1/8” inch of iron filings on the magnets. It was my first change and I did this at 30K miles. Since it’s so easy to do and cheap, I will now service them at 15K intervals. Thanks for sharing that report. Great job.

 

[toyo]

I am in the automotive repair business. I have all the fluids in my vehicles analyzed.

 

[Kanab]

I had my rear end oil checked. I changed out the factory fluid at 15k and put in Mobile1 synthetic. Here is my report with 15k miles on the new oil.

What did the analysis look like on the factory fill after 15K miles?

 

[Bluto]

Do you do any towing?

It is just an open diff, what can go wrong?

 

[toyo]

Pitbull.. The original fluid was just fine also, but did not look as good as the M1.

Bluto... I do some towing, my boat and trailer weigh 7300 lbs, I have pulled it out of the water 2 times this year, I do alot of small misc towing, nothing too heavy. I do however use my 4wd system alot, or shall i say 4lo alot. The main reason i change it so often is that I go through some pretty deep creeks sometimes, that is what worries me, but the report shows no water.

 

[greasefingers]

Are your diff breathers are extended? Since the fill & drain plugs use cut-rings instead of fiber gaskets; this seal is extremely tight.

 

[Kanab]

Toyo, just wondering if the front diff's OEM fluid also looked good after 15K miles? The reason I asked and you can advise me on this. I am coming up on 15K miles and was going to change the front and rear diff's fluid to synthetic, but I might wait until 30K miles if you think it would be a waste. I don't tow anything and drive 70% highway and 30% city. What do you think? Did the OEM look good enough to go 30K with no problem? Thanks

 

[toyo]

Pitbull..Yes the front and center diffs looked pretty good, actually the center looked brand new. We could get away with every 60k if we really wanted to, but I think you and I are in the same "anal" category!!!

 

[Kanab]

Thanks Toyo, I am anal, but based on your experience I am going to wait until 30K miles and do the front and rear diff's and the transfer case. I only plan on keeping this 4runner until it hits around 80-90K miles and then trade for the latest and greatest. So I want to take good care of it but I don't want to over do it and waste money for no good reason. I am going to Mobil 1 5w30 at 15K miles for the engine and will continue to use the Toyota oil filter, and perform the OCI every 5K miles. I've been running Castrol GTX 5w30 and having it changed every 3.75K miles. Both routines are anal and over kill. When I trade this one in someone will get a good used 4runner.