Changed Diffy and Transfer Case Fluids - Very Black

[Winston]

So, I changed out the transfer case and the differential fluids on my '03 Montero with 30k miles on it. The magnetic drain plugs on the differentials had quite a bit of metal on them and the fluid was very black. I was surprised the fluids looked so bad at only 30k miles. The transfer case fluid actually looked much better than the diffy fluids.

I put in Redline Fluids.

I drove around for in 4WD for 30 minutes to warm up the fluids. Checked the diffy fluids with a meat thermometer. They were both 120F. The transfer case was 115F.

 

[IslaVistaMan]

First change-out, Winston? If so, you waited too long -- 30,000 miles is well-beyond the ideal for initial gear oil loads.

Same thing here -- lots of metal on the magnetic plugs at first change, especially the one for the diff. I did mine at 2,000 miles IIRC, but then, I'm pretty hard-core about keeping that stuff fresh.

 

[Winston]

Yes it was the first change-out.

Hmm. My manual doesn't even say to actually change any of those fluids. Just check the level. The Factory service manual says every 30k. I never thought there was much of a breakin for differentials or transfer cases.

I am not one for reduced service intervals for fluids. I will spend for better fluids though.

 

[LargeCarMan]

The data (underground) for some reason...most likely $$$$ for the OEM... shows that changing your fluids within the first few thousand miles will extend the life of your drivetrain 10fold.

The wear metals reak havock on the rest of the parts during breakin. What sounds concerning is your fluid was so black. Glad to see you went with good synthetic fluids at 30K....you did better than most consumers. The first OCI is the most important in new/rebuilt equiptment.

 

[cordeen]

Re: Ford F150
Ford states that the rear axle synthetic 75W-140 is considered lubricated for life unless a leak is suspected or axle is submerged in water. At 46K I finally got around to changing it and sorry I didn't do it sooner. The oil that I suctioned out was similar to old engine oil with a dark silver color present. Seems to me that the fact of being synthetic doesn't make it a lifetime lube. Dry fill listed as 3.3L (6.9 pints) I was able to pump in 3qts. 18oz. of Amsoil Series 2000 gear Lube.

 

[TurboJim]

I would put in some Auto-Rx and then change the fluids out again after a few thousand miles.

 

[ARB1977]

quote:

---

Originally posted by Winston:
So, I changed out the transfer case and the differential fluids on my '03 Montero with 30k miles on it. The magnetic drain plugs on the differentials had quite a bit of metal on them and the fluid was very black. I was surprised the fluids looked so bad at only 30k miles. The transfer case fluid actually looked much better than the diffy fluids.

I put in Redline Fluids.
Youll be happy with redline gear oils i replaced my factory oils at 15K then at 45K and it was still brand new. Im currently using Amsoil Sever Gear 75W90.
I drove around for in 4WD for 30 minutes to warm up the fluids. Checked the diffy fluids with a meat thermometer. They were both 120F. The transfer case was 115F.

---

 

[1040 WreckerMan]

Generally I've found with the transmissions and diff's I've rebuilt (mostly HD trucks) break-in happens quite fast. After about 6.3 miles (my road test route) we put the trucks back into service and they are run loaded again. First drain is at the next engine oil change (at most 12,000 miles currently) then 100k after that. I'd like to change the gear oil at 1200 after a rebuild but the bean counters get upset at dumping several gallons of Eaton LL fluid that soon. 30k is usually too long for break-in fluid, IMO.

I'm not sure what type of transfer case that Montero has, but unless it has some type of viscous clutch (or some other type of limiting clutch) I would not drive around in 4x4 unless it is VERY wet out. It's really hard on the transfer case, front axles, etc. to run them on pavement in 4x4. You didn't specify the weather, but you were probably on the pavement at any rate?

 

[Winston]

The 4WD system is OK to use on dry pavement. It has some sort of clutch system. There is a separate 4WD Lock position that is only for off-road use.

 

[Strjock81]

The company I work for has a mixed fleet of roughly 55 2500 and 3500 Ford and Chevy pickup trucks for outside salespeople that accumulate 200,000 miles each within 4 years of purchase. About half of the miles are pulling trailers from 5K to 15K. They do not ever have us change diff fluid, and failures are basically zilch.

Trannies are done by flush every 50K and rarely do we have issues with them either. We run 5K intervals of 5w-30 in all these gassers and 95% of the engines make it to 200K without having the valve covers off. Surprisingly a lot of these trucks are Chevies and we rarely have Dex-Cool problems either, presumably to rapid accumulation of miles. All the trucks almost are gassers now.

And here I am following Dodge's recommendations on my personal truck swapping 90 bucks worth of syn diff fluid every 15K.

Next fill I am going Schaeffer's #167 in 75w-140 flavor and calling it good until 100K (about 60K miles).