Hi all-

At 20k I changed the diff and transfer cases on my 03 Montero LTD. I
used Royal Purple Syn oil. I was shocked at how dirty and how much
metal 'paste' or shavings were stuck to the magnetic plugs! The truck
runs great, it just concerned me a little. Is this normal? I am
hoping it is because it included a lot of the debris from break-in.
Anyone else seeing the same thing? I changed the oils again at about
35k and it was much less and the fluid was clean. Is this just the way
it goes?

Thanks!

 

If the shavings are very very fine - you are okay. I looked at RP and stayed away from it for my differentials and transfer case for some reason. Make absolutely sure that GL4 is used in the transfer case and GL5 is used in the diffs. Im trying to remember why I did not use RP - I think its rated GL4 and GL5 but its cps viscosity was too high for the transfer case. Remember, do not use a GL5 fluid in the transfer case. GL5 is designed to withstand the extreme pressures of a hypoid gearing. All the gears in the transfer case are within the same axis and not hypoid.

The bottom line is that you will have to monitor the situation. I certainly would not tear down the transfer case for filiings unless it was pieces or chunks coming out of the drain. I would stick to OEM fluids or GL4 only fluid like specialty formulations. I have only noted very fine particles that once wiped with a rag looks like dirty grease in the rag.

 

My initial fill was very black with shavings too. It should be fine.

 

I found the same when I changed mine at 30k. They were all fine no chunks. I did put in both front and rear diff and trnasfer case Mobil 1 75w-90. Not sure if that is ok or not. I belive that it met specs of all three, but now it is too late anyway as I had there for 20k and it is coming due in 10k, which is about a year for me. Any input is appreciated.

 

GL-5 is needed in both differentials.
GL-4 is for the transfer case, as GL-5 can potentially damage the brass on the synchronizer.

there is NO need to waste money on synthetic lubricants of anykind. It helps nothing.