Gear box oil change intervals

[bkgee]

I've looked through my manuals and factory maintenance schedule, and scanned through the FAQ and my memory of threads, but havent found a great answer yet, so I'll put it to the forum - btw, the maint schedule only kept repeating "inspect" for all the intervals, and only added "change" for severe applications (basically towing), but it never stipulated a hard and fast change interval for regular usage...

what is a good oil change interval for gear boxes? I noticed when i changed my gear box fluids at 120k, the front diff looked fairly fresh, the rear diff looked somewhat used, and the transfer case looked the worst of the three (i dont actually know when they were changed previously, but i think at 90k). i'm coming up on 150k, just planning my job... from my observations at the last change, i plan to do the transfer case at a minimum.

additional info: i'm using Mobil1 75W-90, i tow about 3000 lbs a handful of times each year, and i rarely cross deep water (pretty much never put the pumpkin under water).

 

[MilkmanVX]

what is a good oil change interval for gear boxes?

I think you have the Toyota wizards back in Japan stumped on this one ....

If my diffs and gearbox aren't leaking I would continue to inspect as instructed and probably replace every 3 years or so .... that is under normal usage ....

 

[Travis351]

I have been doing it every 100k unless I get into deep water.

 

[bkgee]

Travis, are you saying 100k Km or miles? I always figured at least 60k miles but I could see 100k miles with synthetics... that would be an uneducated assumption though. maybe i'll talk to the folks at blackstone labs

 

[Gottagetone]

30-60k miles depending on usage. Preventative maintenance is much cheaper than repairs. I use M1 as well.

 

[Nottajeep]

change your coolant, diff oil, tranny oil, and transfer case oill every 30K

 

[bkgee]

after some thought, 30k for all gear boxes seems easy enough, although maybe a little excessive and unnecessary (for my personal application) ... i think i will change the transfer case for this 30k interval, and if it looks pretty good I will assume the diffs are good to go another 30. if it looks a bit used i will change them all.

agreed on the coolant change every 30k, a well as a heavy brake fluid bleed/flush.

not trying to get too far off topic, but i've noticed that the steering fluid looks like it gets hammered pretty quick, so i'm thinking of adding a PS flush to the 30k interval. i'm thinking of putting a drain valve in the line to make this an easy operation. will post up if i work out something cool.

 

[Travis351]

Travis, are you saying 100k Km or miles? I always figured at least 60k miles but I could see 100k miles with synthetics... that would be an uneducated assumption though. maybe i'll talk to the folks at blackstone labs

100,000 Miles. Amsoil 90w synthetic. The salesman said I could do $250,000 miles if I kept the water out of it.

If you're doing yours every 30k, you should re-sell the old stuff as cologne...recoup some of the value.

 

[Romer]

Hmm, I have always done it every other year. Sounds liek I am doing it too often

 

[OregonLC]

100,000 Miles. Amsoil 90w synthetic. The salesman said I could do $250,000 miles if I kept the water out of it.

If you're doing yours every 30k, you should re-sell the old stuff as cologne...recoup some of the value.

$250k is a lot to spend on fluid, even if it is Amsoil.

 

[Travis351]

Here's the propaganda from Amsoil. Looks like 50,000 is the minimum and 250,000 is the max, depending the oil and your personal usage.

 

[mechanixhorseman]

If you aren't wheeling 24/7 and you're on synthetic, there shouldn't be any reason to change your diffs/transfer oil less than every 100k. I just changed all mine yesterday at 150,000 and it was as clean as new. Gear oil is expensive and if paying an extra 2-300 a year is worth the peace of mind then by all means go for it, but it's not giving you any more protection and you could otherwise put that money towards a new bumper.

 

[NMuzj100]

Amsoil gear oil came out of both diffs and transfer looking very good at 100k.

Power steering fluid does take a beating. I drain the reservoir and replace at basically every oil change. Very easy to do just unplug the hose and catch the fluid. I also have a filter installed in the return line.

 

[bkgee]

thnx for the additional responses. in my continual rethinking, maybe i will leave the transfer case (along with the diffs) alone until the 180k mile interval PM, and then schedule them every 90k.

i wonder why my transfer case oil was nasty looking at 120k?

 

[SWUtah]

With "normal" "Mall cruiser" use and synthetic fluid, 60k mile intervals are conservative. I've done 60k on previous 100's and when I changed them the fluid looks good and the transfer case fluid still looked new. If your towing or have heavy loads and off road a lot then 30k would work with synthetic

 

[Spike555]

I'm throwing my opinion now...every 50,000 miles change the trans fluid, power steering fluid, diff's and t-case.
Use whatever fluid you want as long as it meets specs.
The only real advantage to full Syn gear oil is cold weather and extreme heat, like heavy towing in the desert.